AUTOSAR E2E Profile 2 Explained: CRC16, DataID, and CAN Communication Protection

AUTOSAR E2E Profile 2 is the second and arguably the more robust of the two original end-to-end safety protocols introduced in AUTOSAR Release 3.1. While E2E Profile 1 remains the most widely deployed profile, AUTOSAR E2E Profile 2 delivers measurably stronger masquerade protection and a superior CRC algorithm — making it the preferred choice for new CAN and FlexRay designs where maximum safety assurance is required without sacrificing the compact header footprint that bandwidth-constrained bus networks demand.

The defining feature of AUTOSAR E2E Profile 2 is its revolutionary approach to Data ID management: instead of a static 16-bit Data ID, it uses a 16-entry DataIDList — a pre-shared array of 16 unique 8-bit values where the specific byte used in each CRC computation is selected by the current counter value. This means the “message key” that protects against masquerade attacks changes with every single transmission, making AUTOSAR E2E Profile 2 significantly harder to attack than Profile 1. Combined with the CRC-8-H2F polynomial (0x2F) — which provides a higher Hamming distance for short automotive messages than the SAE J1850 polynomial used in Profile 1 — AUTOSAR E2E Profile 2 represents a technically superior solution for AUTOSAR E2E CAN FlexRay communication protection at the same 1-byte header overhead cost.

This comprehensive guide covers every technical aspect of AUTOSAR E2E Profile 2: the CRC-8-H2F polynomial mathematics, the complete DataIDList mechanism with generation methodology, the header bit layout, the protect and check algorithms with full C code examples, the state machine configuration, and a thorough automotive functional safety ISO 26262 ASIL D E2E analysis. By the end, you will have everything needed to design, implement, configure, and certify AUTOSAR E2E Profile 2 deployments in production automotive ECU programs.

🔗 Part of the AUTOSAR E2E Master Series on PiEmbSysTech.
Parent page: AUTOSAR E2E Communication Protection: Complete Technical Guide

What is AUTOSAR E2E Profile 2?
History and Background of E2E Profile 2
Architectural Position in AUTOSAR Stack
Complete Technical Specifications
Header Layout and Bit-Level Structure
CRC-8-H2F Polynomial 0x2F — Deep Dive
Sequence Counter Mechanism
AUTOSAR E2E Profile 2 DataIDList — Complete Explanation
DataIDList Generation Methodology
E2E_P02Protect() — Step-by-Step Algorithm
E2E_P02Check() — Step-by-Step Algorithm
E2E Profile 2 State Machine
E2E_P02ConfigType — All Parameters Explained
E2E_P02CheckStatusType — Status Codes
Practical Implementation Guide with Code
ISO 26262 Compliance and ASIL D Analysis
Real-World Automotive Use Cases
E2E Profile 2 vs Profile 1 — Detailed Comparison
Gateway Handling for E2E Profile 2
Advantages of AUTOSAR E2E Profile 2
Limitations and Challenges
Testing Strategy and Fault Injection
Tools and Configuration Support
Frequently Asked Questions
Conclusion

1. What is AUTOSAR E2E Profile 2?

AUTOSAR E2E Profile 2 is a standardized End-to-End (E2E) safety communication protocol defined in the AUTOSAR Classic Platform (CP) specification. It is part of the AUTOSAR E2E Library (SWS_E2ELibrary) and the E2E Protocol Specification (PRS_E2EProtocol), and was introduced in AUTOSAR Release 3.1 alongside Profile 1 to provide a higher-assurance alternative for safety-critical CAN and FlexRay-based automotive communication.

At its core, AUTOSAR E2E Profile 2 uses three safety mechanisms working in concert:

CRC-8-H2F (polynomial 0x2F): An 8-bit cyclic redundancy check computed using the superior H2F polynomial, providing better Hamming distance than the SAE J1850 polynomial used by Profile 1
4-bit Sequence Counter: An incrementing counter (0–14) transmitted with every message, enabling detection of lost messages, repeated messages, and message delays
DataIDList (16-entry rotating Data ID): A pre-agreed 16-byte array where the specific byte used in each CRC computation is indexed by the current counter value, making the effective message key unique for every transmission cycle

The combination of these three mechanisms makes AUTOSAR E2E Profile 2 one of the most elegant safety protocols in the AUTOSAR standard — achieving ISO 26262 ASIL D-compliant fault detection within a compact 2-byte header overhead that fits comfortably within any classic CAN message payload. This is precisely why AUTOSAR E2E CAN FlexRay communication protection using Profile 2 is the default choice for many OEM supplier requirements and automotive safety reference architectures in Europe and globally.

📌 Quick Reference — AUTOSAR E2E Profile 2 at a Glance

Profile Identifier	E2E_02 (AUTOSAR Standard Profile)
CRC Algorithm	CRC-8-H2F, polynomial 0x2F (x⁸+x⁵+x³+x²+x+1), Start: 0xFF, XOR: 0xFF
Counter	4-bit (values 0–14; 15 reserved for init/invalid)
Data ID Mechanism	DataIDList[16] — 16-entry rotating 8-bit Data ID, indexed by counter value
Header Overhead	2 bytes (Byte 0 = CRC, Byte 1 low nibble = Counter)
Header Position	Fixed at start of data (Byte 0 = CRC, Byte 1 = Counter in low nibble)
Maximum Data Length	256 bytes
Primary Bus Target	CAN, CAN FD, FlexRay
Maximum ASIL	ASIL D (with proper safety analysis)
Introduced In	AUTOSAR Release 3.1
AUTOSAR Standard	AUTOSAR_PRS_E2EProtocol, AUTOSAR_SWS_E2ELibrary (Doc ID 428)

2. History and Background of AUTOSAR E2E Profile 2

AUTOSAR E2E Profile 2 was developed in parallel with Profile 1 during the AUTOSAR Release 3.1 specification process (2009). While Profile 1 was a direct standardization of the long-established CRC-8-SAE J1850-based approach used in many existing OEM programs, AUTOSAR E2E Profile 2 was designed from scratch to address specific weaknesses in the Profile 1 design — particularly the relatively weak masquerade protection provided by a static Data ID and the suboptimal Hamming distance of the SAE J1850 polynomial for short CAN messages.

The two key innovations in AUTOSAR E2E Profile 2 over Profile 1 were the adoption of the CRC-8-H2F polynomial (0x2F) — selected specifically for its superior Hamming distance properties in the 8–64 byte message length range common in automotive CAN applications — and the introduction of the rotating DataIDList mechanism, which ensures the message key used in the CRC computation is never the same across consecutive transmissions. This second innovation was particularly significant: in Profile 1’s BOTH/ALT modes, the Data ID alternated between two fixed values. In AUTOSAR E2E Profile 2, it cycles through up to 16 distinct values, each uniquely chosen for each protected data element, making replay and masquerade attacks substantially more difficult to execute undetected.

Since its introduction, AUTOSAR E2E Profile 2 has become one of the two most commonly specified profiles in OEM supplier requirements (alongside Profile 1), with widespread deployment across ABS, EPS, powertrain, and chassis systems in European and Asian automotive programs. The AUTOSAR SWS_E2ELibrary dedicates an entire chapter (Chapter 13 in Release 4.2.2) specifically to the usage and generation methodology for the AUTOSAR E2E Profile 2 DataIDList, reflecting the importance and complexity of this unique mechanism.

3. AUTOSAR E2E Profile 2 in the AUTOSAR Architecture

Like all AUTOSAR E2E profiles, AUTOSAR E2E Profile 2 is implemented entirely at the software application layer, independent of the physical communication bus and the QM-rated Basic Software (BSW). This architectural independence is what enables AUTOSAR E2E CAN FlexRay communication protection using Profile 2 to satisfy automotive functional safety ISO 26262 ASIL D E2E requirements even when the underlying communication infrastructure is not safety-certified.

╔═══════════════════════════════════════════════════════════════════╗
║                APPLICATION LAYER (ASIL D)                         ║
║  ┌──────────────────────┐        ┌──────────────────────────────┐ ║
║  │   SW-C Sender         │        │   SW-C Receiver               │ ║
║  │  [e.g. ESP Controller]│        │   [e.g. Brake Actuator ECU]   │ ║
║  └──────────┬────────────┘        └──────────────┬───────────────┘ ║
║             │ E2EPW_Write()                       │ E2EPW_Read()   ║
║             │ → E2E_P02Protect()                  │ → E2E_P02Check()║
║             ▼                                     ▲               ║
║  ┌─────────────────────────────────────────────────────────────┐  ║
║  │         E2E LIBRARY — Profile 2 Functions  (ASIL D)         │  ║
║  │  CRC-8-H2F + Counter + DataIDList[counter % 16]             │  ║
║  └─────────────────────────────────────────────────────────────┘  ║
╠═══════════════════════════════════════════════════════════════════╣
║                    RTE (QM or ASIL D)                             ║
╠═══════════════════════════════════════════════════════════════════╣
║                 BASIC SOFTWARE (QM)                               ║
║  COM ──► PDU Router ──► CAN/FlexRay Driver ──► Physical Bus       ║
╚═══════════════════════════════════════════════════════════════════╝

Key: E2E_P02Protect() adds CRC + Counter to data BEFORE Rte_Write()
     E2E_P02Check()   verifies CRC + Counter AFTER  Rte_Read()
     DataIDList[counter] is the rotating message key — never transmitted on bus

The diagram above illustrates the crucial design property of AUTOSAR E2E Profile 2: the DataIDList values are never transmitted on the CAN or FlexRay bus. They exist only in the software configuration of both sender and receiver, embedded in the E2E_P02ConfigType structure. A message intercepted on the bus will not contain the DataID — it is a virtual, pre-shared secret that only the legitimate sender and receiver know. This is why the AUTOSAR E2E Profile 2 DataIDList mechanism provides qualitatively stronger masquerade protection than Profile 1’s transmitted or implicitly-included static Data ID.

4. AUTOSAR E2E Profile 2 — Complete Technical Specifications

The following table provides the complete, authoritative technical specification of AUTOSAR E2E Profile 2 as defined in AUTOSAR_SWS_E2ELibrary Release 4.3.1 and AUTOSAR_PRS_E2EProtocol. Every engineer implementing AUTOSAR E2E CAN FlexRay communication protection with Profile 2 should reference these parameters precisely.

Parameter	Value / Description
Profile Identifier	E2E_02
CRC Algorithm	CRC-8-H2F (also called CRC-8-AUTOSAR), polynomial 0x2F (x⁸+x⁵+x³+x²+x+1)
CRC Start Value	0xFF
CRC XOR Output Value	0xFF
CRC Field Size	8 bits (1 byte), always at Byte 0 of the data element
Counter Size	4 bits, values 0–14 (15 is reserved/init)
Counter Position	Fixed at low nibble of Byte 1 (bits 0–3 of second byte). Upper nibble of Byte 1 is available for signal data.
Counter Increment	+1 per transmission, wraps 14→0 (skips 15)
Data ID Mechanism	DataIDList[16] — array of 16 unique 8-bit values. CRC computed using `DataIDList[Counter % 16]` as the key byte. Never transmitted on bus.
Maximum Data Length	256 bytes (2048 bits) including header — much larger than Profile 1’s 30-byte maximum
CRC Computation Scope	Over: Data[1..N-1] (all data bytes except CRC byte at Byte 0), followed by DataIDList[Counter] as the key
Timeout Detection	Yes — via counter evaluation (non-blocking receiver read)
Supported Bus Types	CAN, CAN FD, FlexRay, intra-ECU
Communication Patterns	1:1 (point-to-point), 1:N (broadcast/multicast to multiple receivers)
Maximum ASIL Rating	ASIL D
CRC Library Dependency	Calls `Crc_CalculateCRC8H2F()` from AUTOSAR CRC Library (Crc module)
Note: CP Only	AUTOSAR E2E Profile 2 is defined for Classic Platform (CP) only. It is not included in the AUTOSAR Adaptive Platform (AP) E2E Protocol Specification.

5. AUTOSAR E2E Profile 2 Header Layout and Bit-Level Structure

Unlike Profile 1 where the CRC and counter positions are configurable, AUTOSAR E2E Profile 2 uses a fixed header layout with no configuration options. This design decision simplifies implementation and eliminates a category of integration errors (mismatched offset configurations) that can plague Profile 1 deployments. The fixed layout is one of the reasons AUTOSAR E2E Profile 2 is often easier to implement correctly across multi-supplier programs.

Byte Index:    0                          1                        2 .. N
              ┌──────────────────────────┬─────────────────────────┬──────────────────┐
Bit Layout:   │  7   6   5   4   3   2   1   0  │  7  6  5  4 │  3   2   1   0  │          │
              │                          │           │                           │          │
Content:      │      CRC-8-H2F (8 bits)  │ Signal    │ Counter (4 bits, 0–14)   │ Signal   │
              │   [computed over Bytes   │ data      │ [Sequence Counter]        │ data     │
              │    1..N + DataIDList key]│ nibble    │                           │ bytes    │
              └──────────────────────────┴─────────────────────────┴──────────────────┘
                ◄──────── Byte 0 ────────►◄──────────── Byte 1 ───────────────►◄── Data ──►

FIXED POSITIONS (no CRCOffset / CounterOffset parameters in Profile 2):
  CRC byte:     Byte index 0  (bit offset 0)
  Counter:      Low nibble of Byte index 1  (bits 0–3 of Byte 1)
  Signal data:  Upper nibble of Byte 1 + Bytes 2 through N

DataIDList:   NOT transmitted. Virtual key used only in CRC computation.
              DataIDList[Counter] selects the key for each transmission.

This fixed 2-byte header means that in a classic 8-byte CAN message, AUTOSAR E2E Profile 2 leaves 6 full bytes plus a 4-bit nibble available for application signal data — essentially the same payload efficiency as Profile 1. For CAN FD or FlexRay frames, the overhead remains a fixed 2 bytes regardless of payload length (up to 256 bytes), making AUTOSAR E2E Profile 2 progressively more space-efficient as data length increases.

6. E2E Profile 2 CRC-8-H2F Polynomial 0x2F — Deep Dive

The E2E Profile 2 CRC-8-H2F 0x2F polynomial is one of the most carefully chosen safety parameters in the AUTOSAR E2E specification. Understanding why this polynomial was selected for AUTOSAR E2E Profile 2 — and how it outperforms the SAE J1850 polynomial used in Profile 1 — is essential for engineers performing quantitative safety analysis for automotive functional safety ISO 26262 ASIL D E2E compliance.

The H2F Polynomial

G(x) = x⁸ + x⁵ + x³ + x² + x + 1
Hexadecimal (without leading 1): 0x2F
Binary: 0010 1111
Full polynomial with leading bit: 0x12F = 100101111₂
Start Value: 0xFF
XOR Output Value: 0xFF
AUTOSAR CRC Library Function: Crc_CalculateCRC8H2F()
Reference Check Value: 0xDF (CRC of 0x00..0x0F with initial value 0xFF)

The “H2F” designation refers to the hexadecimal representation of the polynomial: 0x2F (with the leading bit of the degree-8 polynomial implied). The name is sometimes written as “CRC-8/AUTOSAR” in non-AUTOSAR literature, reflecting that this polynomial was essentially standardized by and for the AUTOSAR specification.

Why CRC-8-H2F is Superior to CRC-8-SAE J1850 for Automotive Messages

The critical performance metric for CRC selection in safety protocols is Hamming distance — the minimum number of bit errors in any message that will be undetected by the CRC. A higher minimum Hamming distance means stronger guaranteed fault detection.

For the typical message lengths found in automotive CAN applications (8–64 bytes), the E2E Profile 2 CRC-8-H2F 0x2F polynomial achieves a minimum Hamming distance of 6 for messages up to approximately 119 data bits — meaning it guarantees detection of all error patterns involving 5 or fewer corrupted bits. The SAE J1850 polynomial (0x1D used in Profile 1) achieves a minimum Hamming distance of 4 for the same message lengths — guaranteeing detection of only 3-bit errors. This is a substantial practical difference in a harsh automotive EMI environment where multi-bit burst errors are common.

CRC Polynomial	Used In	Min Hamming Distance (HD)	Max Protected Data Length
CRC-8-SAE J1850 (0x1D)	E2E Profile 1	HD=4 (detects all ≤3-bit errors)	~119 data bits for HD=4
CRC-8-H2F (0x2F)	E2E Profile 2, Profile 11	HD=6 (detects all ≤5-bit errors)	~119 data bits for HD=6
CRC-16-CCITT (0x1021)	E2E Profile 5, 6, 22	HD=4 for longer messages	Up to 32767 data bits
CRC-32 (0xF4ACFB13)	E2E Profile 4	HD=6 for medium messages	Up to 32571 bits

CRC-8-H2F and Independence from Bus CRC

A fundamental requirement from the AUTOSAR SRS_E2E (SRS_E2E_08533) is that the CRC polynomial used in an E2E profile must be different from the CRC used by the underlying physical communication protocol. The E2E Profile 2 CRC-8-H2F 0x2F polynomial satisfies this requirement perfectly:

CAN bus: Uses CRC-15 (hardware-implemented). CRC-8-H2F (software-only) is completely independent.
FlexRay: Uses CRC-24 (hardware). CRC-8-H2F is completely independent.
CAN FD: Uses CRC-17 or CRC-21 (hardware). CRC-8-H2F is completely independent.

This independence ensures that any error pattern that passes the hardware bus CRC is still subject to a completely independent 8-bit check at the application layer. The two CRC layers together provide joint fault detection far superior to either layer alone — a key property required for automotive functional safety ISO 26262 ASIL D E2E compliance in the context of end-to-end protection over a QM communication stack.

CRC-8-H2F Computation Example

/* CRC-8-H2F reference values for verification */
/* Input: 0x00, 0x00, 0x00, 0x00 (4 zero bytes), start = 0xFF */
/* Expected CRC: 0x12 */

/* Input: 0x00..0x0F (bytes 0–15), start = 0xFF */
/* Expected CRC (check value): 0xDF */

/* Python verification: */
/* import e2e */
/* crc = e2e.crc.calculate_crc8_h2f(b"\x00\x00\x00\x00") */
/* assert crc == 0x12 */

7. Sequence Counter Mechanism in AUTOSAR E2E Profile 2

The counter in AUTOSAR E2E Profile 2 is a 4-bit field placed in the low nibble of Byte 1 of the data element. Its role and behavior are very similar to Profile 1’s counter, but with one critical operational difference: in AUTOSAR E2E Profile 2, the counter value directly indexes the AUTOSAR E2E Profile 2 DataIDList array — making the counter not just a fault detection mechanism, but also the index that determines which message key is used in the CRC computation for this particular transmission.

Counter Behavior

Sender: Starts at 0 after initialization. Increments by 1 with each E2E_P02Protect() call. Wraps from 14 back to 0 (skipping 15, which is reserved).
Receiver: Reads the counter from the received Byte 1 low nibble. Computes the expected counter value and delta. Uses the received counter value to look up the correct DataIDList entry for CRC verification.
Counter range: 0–14 (15 values). Value 15 (0xF) is reserved for initialization and treated as invalid by the receiver.
DataIDList indexing: DataIDList[Counter % 16] — since counter values 0–14 are used and the list has 16 entries (indices 0–15), counter values 0–14 map to DataIDList entries 0–14. DataIDList[15] is effectively never used in practice (counter never reaches 15 in normal operation).

Counter as Fault Detection

Counter Situation	Delta Computed	Fault Detected	Status Reported
Normal reception	delta = 1	None	OK or OKSOMELOST
1 message lost	delta = 2	Message loss (if delta ≤ MaxDeltaCounter)	OKSOMELOST
Multiple messages lost	delta > MaxDeltaCounter	Excessive message loss	WRONGSEQUENCE
Message repeated	delta = 0	Repetition fault	REPEATED
Timeout (no new data)	N/A (no new message)	Timeout / sender failure	NONEWDATA
CRC mismatch	Any	Data corruption or masquerade	ERROR

8. AUTOSAR E2E Profile 2 DataIDList — Complete Explanation

The AUTOSAR E2E Profile 2 DataIDList is the most distinctive and technically significant innovation that separates AUTOSAR E2E Profile 2 from Profile 1. Understanding it deeply is essential for anyone working with AUTOSAR E2E CAN FlexRay communication protection using Profile 2.

What is the DataIDList?

The AUTOSAR E2E Profile 2 DataIDList is a pre-agreed array of 16 unique 8-bit bytes (uint8 DataIDList[16]) stored in the E2E_P02ConfigType configuration structure of both the sender and receiver. This array functions as a virtual, rotating message key. For every transmission of the protected data element, the CRC is computed using one specific byte from this array — selected by the current counter value as the index.

/* Example DataIDList for a wheel speed signal (FL wheel) */
uint8 DataIDList_WheelSpeedFL[16] = {
    0x4B,  /* Counter = 0  → CRC uses DataIDList[0] = 0x4B */
    0x7A,  /* Counter = 1  → CRC uses DataIDList[1] = 0x7A */
    0x2C,  /* Counter = 2  → CRC uses DataIDList[2] = 0x2C */
    0xF1,  /* Counter = 3  → CRC uses DataIDList[3] = 0xF1 */
    0x93,  /* Counter = 4  → CRC uses DataIDList[4] = 0x93 */
    0x0E,  /* Counter = 5  → CRC uses DataIDList[5] = 0x0E */
    0xD8,  /* Counter = 6  → CRC uses DataIDList[6] = 0xD8 */
    0x65,  /* Counter = 7  → CRC uses DataIDList[7] = 0x65 */
    0xB4,  /* Counter = 8  → CRC uses DataIDList[8] = 0xB4 */
    0x37,  /* Counter = 9  → CRC uses DataIDList[9] = 0x37 */
    0xE2,  /* Counter = 10 → CRC uses DataIDList[10] = 0xE2 */
    0x1F,  /* Counter = 11 → CRC uses DataIDList[11] = 0x1F */
    0xA6,  /* Counter = 12 → CRC uses DataIDList[12] = 0xA6 */
    0x5D,  /* Counter = 13 → CRC uses DataIDList[13] = 0x5D */
    0xC9,  /* Counter = 14 → CRC uses DataIDList[14] = 0xC9 */
    0x80,  /* Counter = 15 → NEVER USED (counter 15 is reserved) */
};

Why the Rotating DataIDList Provides Stronger Masquerade Protection

Consider a masquerade attack scenario: an attacker attempts to inject a fake wheel speed signal by replaying a previously captured valid CAN message. In AUTOSAR E2E Profile 2, the attacker would need to know:

The correct counter value for the current transmission cycle
The correct DataIDList entry for that specific counter value
The CRC-8-H2F algorithm

Points 1 and 3 might be observable or guessable from bus traffic analysis. But Point 2 — the DataIDList entries — are never transmitted on the bus. They exist only in the ECU firmware. This means an attacker who captures bus traffic and reverse-engineers the CRC algorithm still cannot craft a valid fake message without knowledge of the DataIDList. In contrast, Profile 1’s DataID (even in BOTH/ALT mode) eventually reveals both bytes of the Data ID through successive transmissions since the alternation pattern is observable.

AUTOSAR E2E Profile 2 DataIDList Is Implicit (Never Transmitted)

This is a fundamental property that must be understood: the AUTOSAR E2E Profile 2 DataIDList values are implicit — they appear nowhere in the transmitted CAN or FlexRay message. The bus only carries the CRC byte (Byte 0), the counter nibble (Byte 1 low nibble), and the application signal data. The DataIDList entry used for the CRC computation is a virtual, pre-shared secret embedded in ECU software on both sides of the communication link.

9. AUTOSAR E2E Profile 2 DataIDList Generation Methodology

Generating a correct and secure AUTOSAR E2E Profile 2 DataIDList is one of the most practically important and least well-documented aspects of Profile 2 deployment. The AUTOSAR SWS_E2ELibrary dedicates Chapter 13 specifically to this topic, providing examples of both correct and incorrect DataIDList generation approaches. Here we provide a comprehensive guide to DataIDList generation.

Requirements for a Valid DataIDList

The AUTOSAR E2E Profile 2 DataIDList for a given data element must satisfy the following requirements:

System-level uniqueness: The DataIDList for each protected data element must be unique system-wide. No two data elements that communicate between the same sender-receiver ECU pair should share the same DataIDList.
16 distinct values: Ideally, all 16 entries in the DataIDList should be distinct to maximize protection against counter-indexed guessing. While not strictly mandatory in the specification, identical or patterned entries significantly reduce masquerade protection strength.
Pre-shared agreement: The same DataIDList must be configured identically in both the sender ECU and all receiver ECUs. A mismatch of even one byte will cause permanent CRC failures for that counter value.
Offline generation: The DataIDList is generated offline (at system design time), not at runtime. It is a static configuration parameter.

DataIDList Generation Approaches

Approach A — Systematic from a Master Data ID (AUTOSAR Chapter 13 Method)

The AUTOSAR specification suggests deriving the DataIDList from a single 16-bit “master Data ID” using a deterministic algorithm. One common approach is:

/* Generate DataIDList from a 16-bit master Data ID */
/* Example: masterDataID = 0xABCD */
void GenerateDataIDList(uint16 masterDataID, uint8 DataIDList[16])
{
    /* Method: mix high byte, low byte, and counter index */
    for (uint8 i = 0; i < 16; i++) {
        /* XOR low byte with index, then XOR result with high byte */
        DataIDList[i] = (uint8)((masterDataID & 0xFF) ^ i)
                        ^ (uint8)((masterDataID >> 8) & 0xFF);
    }
}

/* Example: masterDataID = 0xABCD → 0xCD^0x00^0xAB=0x66,
                                      0xCD^0x01^0xAB=0x67, etc. */

Approach B — Cryptographically Random Generation

For maximum masquerade protection, generate all 16 DataIDList bytes using a cryptographically secure random number generator during system design. Store the result in the vehicle communication matrix and program it into both sender and receiver ECUs during production. This approach provides the strongest security but requires a robust system-level configuration management process.

Approach C — OEM-Specified Fixed Values

Many OEMs provide pre-defined DataIDList tables in their supplier interface requirements documents, with unique values assigned to each protected signal by the OEM system architect. This is the most common approach in production programs. As a supplier, your role is to implement the specified DataIDList exactly — no generation required, but verification that both sender and receiver ECUs are programmed with identical values is critical.

DataIDList Generation Pitfalls (From AUTOSAR Chapter 13 Examples)

The AUTOSAR specification Chapter 13 examples specifically warn against the following DataIDList generation pitfalls that have caused real-world integration failures:

Using sequential values (0x00, 0x01, 0x02…): Creates predictable patterns that reduce masquerade protection
Reusing the same DataIDList for two different signals between the same ECU pair: Makes it impossible to detect signal substitution (message from one signal accepted as another)
Symmetric or palindromic patterns: DataIDList[0] = DataIDList[15], DataIDList[1] = DataIDList[14], etc. Creates detectable patterns
All-zero or all-same values: The pathological case where all 16 DataIDList entries are identical. Defeats the rotating key mechanism entirely, reducing AUTOSAR E2E Profile 2 to a fixed-key scheme no stronger than Profile 1 LOW mode

10. E2E_P02Protect() — Sender Algorithm Step by Step

The E2E_P02Protect() function is the sender-side API of AUTOSAR E2E Profile 2. It is called once per transmission cycle, immediately before passing data to Rte_Write() or the E2E Protection Wrapper.

Function Signature

Std_ReturnType E2E_P02Protect(
    const E2E_P02ConfigType*   ConfigPtr,   /* [in]     Static configuration      */
    E2E_P02ProtectStateType*   StatePtr,    /* [in/out] Current protect state      */
    uint8*                     DataPtr      /* [in/out] Data buffer (modified)     */
);

Protect Algorithm — Step by Step

Validate inputs: Check for NULL pointers and valid DataLength (must be ≥ 2 bytes, multiple of 8). Return E2E_E_INPUTERR_NULL or E2E_E_INPUTERR_WRONG on failure.
Write Counter: Write the low nibble of StatePtr->Counter into the low nibble of DataPtr[1]:DataPtr[1] = (DataPtr[1] & 0xF0) | (StatePtr->Counter & 0x0F);
Zero CRC byte: Set DataPtr[0] = 0x00 (CRC byte cleared before computation).
Select DataIDList entry: Look up the rotating key:uint8 dataID = ConfigPtr->DataIDList[StatePtr->Counter % 16];
Compute CRC-8-H2F: Compute CRC over:
- First, DataPtr[1] through DataPtr[DataLength/8 - 1] (all data bytes excluding CRC byte at Byte 0)
- Then the selected dataID byte appended as the final byte in the CRC computation
uint8 crc = Crc_CalculateCRC8H2F(&DataPtr[1], DataLen-1, 0xFF, TRUE); uint8 computed_crc = Crc_CalculateCRC8H2F(&dataID, 1, crc, FALSE);
Write CRC: DataPtr[0] = computed_crc;
Increment Counter: StatePtr->Counter = (StatePtr->Counter >= 14) ? 0 : StatePtr->Counter + 1;
Return: E2E_E_OK

Complete E2E_P02Protect() Code Example

/* AUTOSAR E2E Profile 2 Protect — Conceptual C Implementation */
Std_ReturnType E2E_P02Protect(
    const E2E_P02ConfigType  *Config,
    E2E_P02ProtectStateType  *State,
    uint8                    *Data)
{
    uint8  dataID;
    uint8  crc;
    uint16 dataLen;

    /* Input validation */
    if ((Config == NULL_PTR) || (State == NULL_PTR) || (Data == NULL_PTR)) {
        return E2E_E_INPUTERR_NULL;
    }
    if ((Config->DataLength < 16U) || ((Config->DataLength % 8U) != 0U)) {
        return E2E_E_INPUTERR_WRONG;
    }

    dataLen = Config->DataLength / 8U;  /* Convert bits to bytes */

    /* Step 1: Write counter into low nibble of Byte 1 */
    Data[1] = (Data[1] & 0xF0U) | (State->Counter & 0x0FU);

    /* Step 2: Zero CRC byte */
    Data[0] = 0x00U;

    /* Step 3: Select rotating DataIDList entry indexed by counter */
    dataID = Config->DataIDList[State->Counter % 16U];

    /* Step 4: Compute CRC-8-H2F over Data[1..N-1] then DataIDList entry */
    crc = Crc_CalculateCRC8H2F(&Data[1], (uint32)(dataLen - 1U), 0xFFU, TRUE);
    crc = Crc_CalculateCRC8H2F(&dataID,  1U,                      crc,   FALSE);

    /* Step 5: Write computed CRC into Byte 0 */
    Data[0] = crc;

    /* Step 6: Increment counter (wrap: 14 → 0, never use 15) */
    State->Counter = (State->Counter >= 14U) ? 0U : (State->Counter + 1U);

    return E2E_E_OK;
}

11. E2E_P02Check() — Receiver Algorithm Step by Step

The E2E_P02Check() function is the receiver-side API of AUTOSAR E2E Profile 2. It is called after each Rte_Read() to verify the received data before the application SW-C processes it.

Function Signature

Std_ReturnType E2E_P02Check(
    const E2E_P02ConfigType*  ConfigPtr,   /* [in]     Static configuration     */
    E2E_P02CheckStateType*    StatePtr,    /* [in/out] Current check state       */
    const uint8*              DataPtr      /* [in]     Received data buffer      */
);

Check Algorithm — Step by Step

Validate inputs (NULL and parameter checks as in Protect).
Check NewDataAvailable flag. If FALSE, status = NONEWDATA, update state machine, return.
Read received Counter: uint8 receivedCounter = DataPtr[1] & 0x0F;
Read received CRC: uint8 receivedCRC = DataPtr[0];
Select DataIDList entry using received counter: uint8 dataID = Config->DataIDList[receivedCounter % 16];
Recompute CRC-8-H2F over DataPtr[1..N-1] then dataID byte (same order as sender), with CRC byte position set to 0x00 for computation.
Compare CRC: If computedCRC != receivedCRC → set error flag (data corruption or wrong DataID / masquerade).
Evaluate counter delta:delta = (receivedCounter - StatePtr->LastValidCounter + 15) % 15
Check delta against MaxDeltaCounter:
- delta == 0 → REPEATED
- delta == 1 → OK
- 1 < delta ≤ MaxDeltaCounter → OKSOMELOST
- delta > MaxDeltaCounter → WRONGSEQUENCE
Update State Machine based on combined CRC and counter result.
Update LastValidCounter if status is OK or OKSOMELOST.
Return E2E_E_OK. Actual result is in StatePtr->Status.

Complete Receiver Handling Code Example for AUTOSAR E2E Profile 2

/* Full receiver-side E2E Profile 2 handling in an AUTOSAR SW-C runnable */
void ESC_ReceiveSteeringTorque(void)
{
    SteeringTorqueDataType rxData;
    uint32 e2ePwStatus;

    /* Option A: Using E2E Protection Wrapper (older AUTOSAR releases) */
    e2ePwStatus = E2EPW_Read_SteeringTorque_Data(&rxData);

    /* Extract E2E_P02Check status from byte 2 of the 32-bit return value */
    uint8 e2eStatus = (uint8)((e2ePwStatus >> 16U) & 0xFFU);

    switch (e2eStatus)
    {
        case E2E_P02STATUS_OK:
            /* Perfect: CRC-8-H2F matched, counter delta = 1 */
            ESC_ProcessSteeringTorque(rxData.TorqueNm);
            break;

        case E2E_P02STATUS_OKSOMELOST:
            /* CRC OK but 1–MaxDelta messages lost; data still usable */
            ESC_ProcessSteeringTorque(rxData.TorqueNm);
            Dem_ReportErrorStatus(ESC_E2E_SomeLostDEM, DEM_EVENT_STATUS_FAILED);
            break;

        case E2E_P02STATUS_INITIAL:
            /* First reception after init — do not use until trustworthy */
            ESC_ApplySafeDefault();
            break;

        case E2E_P02STATUS_REPEATED:
            /* Same counter received twice — stale/replayed message */
            ESC_ApplySafeDefault();
            Dem_ReportErrorStatus(ESC_E2E_RepeatDEM, DEM_EVENT_STATUS_FAILED);
            break;

        case E2E_P02STATUS_WRONGSEQUENCE:
        case E2E_P02STATUS_ERROR:
        default:
            /* CRC failure (corruption or masquerade) or excessive message loss */
            ESC_ApplySafeDefault();
            Dem_ReportErrorStatus(ESC_E2E_ErrorDEM, DEM_EVENT_STATUS_FAILED);
            ESC_TriggerSafetyDegradation();
            break;
    }
}

12. AUTOSAR E2E Profile 2 State Machine

AUTOSAR E2E Profile 2 uses the same shared E2E state machine architecture as all other AUTOSAR E2E profiles. The state machine ensures hysteretic, noise-tolerant safety decisions by tracking reception history across multiple cycles — a critical requirement for automotive functional safety ISO 26262 ASIL D E2E deployments.

State Machine Overview

State	Meaning	Data Usable?	Exits When
INIT	Initial state after `E2E_P02CheckInit()`. No reliable reception history yet.	❌ No	MinOkStateInit consecutive OK → VALID MaxErrorStateInit errors → INVALID
VALID	Communication is healthy and trustworthy. CRC and counter checks passing consistently.	✅ Yes	MaxErrorStateValid consecutive errors → INVALID
INVALID	Communication has degraded beyond tolerance. Data MUST NOT be used by safety function.	❌ No	MinOkStateInvalid consecutive OK → VALID

State Machine Configuration Parameters for AUTOSAR E2E Profile 2

/* Typical ASIL D configuration for a 10ms safety-critical CAN signal */
/* Explanation of each threshold: */

MaxDeltaCounter     = 1U;   /* Expect exactly counter+1 each 10ms cycle.
                               For 1:N communication or jitter-prone networks,
                               increase to 2 or 3 to reduce false WRONGSEQUENCE
                               reports. */

MinOkStateInit      = 3U;   /* Require 3 consecutive OK receptions during INIT
                               before declaring VALID. Prevents false-positive
                               VALID state from a brief lucky sequence. */

MaxErrorStateInit   = 3U;   /* After 3 errors in INIT, declare INVALID.
                               Safety reaction triggered before unproven
                               communication is relied upon. */

MinOkStateValid     = 1U;   /* In VALID state, 1 OK is enough to stay VALID.
                               Avoids excessive state churn from isolated faults.*/

MaxErrorStateValid  = 3U;   /* After 3 consecutive errors in VALID, declare
                               INVALID. 3×10ms = 30ms reaction time budget. */

MinOkStateInvalid   = 5U;   /* Require 5 consecutive OK receptions to recover
                               from INVALID. Conservative recovery threshold for
                               ASIL D. */

MaxErrorStateInvalid= 0U;   /* Stay INVALID — errors in INVALID state do not
                               extend INVALID, but OK receptions are still
                               counted toward MinOkStateInvalid. */

13. E2E_P02ConfigType — All Parameters Explained

The E2E_P02ConfigType structure is the complete static configuration for AUTOSAR E2E Profile 2. It is initialized at system startup and must be identical on both sender and receiver sides.

typedef struct {

    uint8   DataIDList[16];   /* THE CORE INNOVATION OF E2E PROFILE 2:
                                 16-entry array of 8-bit Data ID bytes.
                                 DataIDList[i] is used when counter == i.
                                 NEVER transmitted on bus — virtual key only.
                                 Must be IDENTICAL on sender and all receivers.
                                 Must be UNIQUE per protected data element. */

    uint16  DataLength;       /* Length of protected data in BITS.
                                 Must be a multiple of 8.
                                 Includes CRC byte (Byte 0) and counter (Byte 1 low nibble).
                                 Minimum: 16 bits (2 bytes). Maximum: 2048 bits (256 bytes). */

    uint8   MaxDeltaCounterInit;   /* Max allowed counter delta in INIT state.
                                      Typically 1–2 for 1:1 communication. */

    uint8   MaxDeltaCounter;       /* Max allowed counter delta in VALID/INVALID state.
                                      Determines how many lost messages are tolerated
                                      before WRONGSEQUENCE is reported. */

    uint8   MinOkStateInit;        /* Consecutive OK receptions in INIT → transition to VALID */

    uint8   MaxErrorStateInit;     /* Consecutive errors in INIT → transition to INVALID */

    uint8   MinOkStateValid;       /* Consecutive OK in VALID to stay VALID (typically 1) */

    uint8   MaxErrorStateValid;    /* Consecutive errors in VALID → transition to INVALID */

    uint8   MinOkStateInvalid;     /* Consecutive OK in INVALID → recovery to VALID */

    uint8   MaxErrorStateInvalid;  /* Consecutive errors in INVALID (typically 0 = stay INVALID) */

} E2E_P02ConfigType;

Example Configuration — ABS Wheel Speed FR (CAN, 10ms, ASIL D)

/* AUTOSAR E2E Profile 2 configuration for Front-Right wheel speed signal */
static const E2E_P02ConfigType E2E_P02_Config_WheelSpeedFR = {
    /* DataIDList — unique values for FR wheel speed, OEM-specified */
    .DataIDList = {
        0x4B, 0x7A, 0x2C, 0xF1, 0x93, 0x0E, 0xD8, 0x65,
        0xB4, 0x37, 0xE2, 0x1F, 0xA6, 0x5D, 0xC9, 0x80
    },
    .DataLength          = 64U,   /* 8 bytes = 64 bits (full CAN payload) */
    .MaxDeltaCounterInit = 1U,
    .MaxDeltaCounter     = 1U,    /* 10ms cycle, expect exactly counter+1 */
    .MinOkStateInit      = 3U,
    .MaxErrorStateInit   = 3U,
    .MinOkStateValid     = 1U,
    .MaxErrorStateValid  = 3U,    /* 3 errors × 10ms = 30ms reaction time */
    .MinOkStateInvalid   = 5U,
    .MaxErrorStateInvalid= 0U,
};

14. E2E_P02CheckStatusType — Status Codes and Application Handling

After every E2E_P02Check() call, the receiver SW-C reads StatePtr->Status to determine the quality of the received data. The AUTOSAR E2E Profile 2 status codes are defined in E2E_P02CheckStatusType:

Status Code	Hex	Meaning	Application Action
`E2E_P02STATUS_OK`	0x00	CRC-8-H2F matched AND counter delta exactly 1. Perfect reception.	✅ Use data
`E2E_P02STATUS_NONEWDATA`	0x01	No new data available from RTE (possible timeout or call rate mismatch).	⚠️ Apply safe default if timeout exceeded
`E2E_P02STATUS_WRONGSEQUENCE`	0x02	CRC OK but counter delta exceeded MaxDeltaCounter.	⚠️ Apply safe default; log DTC
`E2E_P02STATUS_ERROR`	0x03	CRC-8-H2F mismatch. Data corruption, masquerade, or wrong DataIDList.	❌ Discard; apply safe default; trigger safety reaction
`E2E_P02STATUS_REPEATED`	0x08	CRC OK but counter delta = 0 (message received twice).	⚠️ Discard as stale; log repetition DTC
`E2E_P02STATUS_OKSOMELOST`	0x20	CRC OK and counter delta between 2 and MaxDeltaCounter (some messages lost).	⚠️ Use data; log message-loss DTC
`E2E_P02STATUS_INITIAL`	0x40	State machine in INIT — first reception after initialization.	⚠️ Do not use data yet

15. Practical Implementation Guide for AUTOSAR E2E Profile 2

Implementing AUTOSAR E2E Profile 2 correctly in a production AUTOSAR project involves several concrete steps beyond simply calling the library functions. This section walks through the complete workflow for a typical AUTOSAR E2E CAN FlexRay communication protection deployment using Profile 2.

Step 1 — Obtain or Generate the DataIDList

Before any code is written, obtain the AUTOSAR E2E Profile 2 DataIDList for each protected signal from the OEM’s communication specification or generate it using the methodology described in Section 9. Document the DataIDList values in the vehicle communication matrix. Treat the DataIDList with the same change-control rigor as cryptographic keys — mismatching DataIDList values between sender and receiver will cause 100% CRC failures for the affected counter positions.

Step 2 — Enable CRC-8-H2F in the Crc Module

In your AUTOSAR BSW configuration tool, navigate to the Crc module configuration and enable CrcCrc8H2F. The Crc_CalculateCRC8H2F() function called by the AUTOSAR E2E Profile 2 library will not link without this. Note: this is a different function from the Crc_CalculateCRC8() used by Profile 1 — both can be enabled simultaneously if your ECU uses both profiles.

Step 3 — Configure the E2E_P02ConfigType

Populate the E2E_P02ConfigType structure (as shown in Section 13) with the DataIDList values and state machine thresholds. Ensure DataLength matches the actual CAN payload size × 8 (in bits). Verify that MaxDeltaCounter accounts for any jitter or burst retransmission in the network design.

Step 4 — Choose E2E Transformer or Protection Wrapper

AUTOSAR R4.2+ (E2E Transformer recommended): Configure the E2E Transformer in your AUTOSAR toolchain. Set profile to Profile 2, configure DataIDList and state machine parameters in the transformer configuration. The tool generates all necessary integration code automatically.

Older releases or manual integration (Protection Wrapper): Generate protection wrappers following the AUTOSAR SWS_E2ELibrary Section 12 methodology. The wrapper functions handle the Rte_Write/Read calls plus E2E_P02Protect/Check invocations.

Step 5 — Initialize State Structures

/* Initialize E2E Profile 2 states in ECU startup routine */
void SafetyCom_P02_Init(void)
{
    /* Sender ECU */
    E2E_P02ProtectInit(&E2E_P02_ProtectState_WheelSpeedFR);

    /* Receiver ECU */
    E2E_P02CheckInit(&E2E_P02_CheckState_WheelSpeedFR);
    /* After init: CheckState.Counter = 0, State = INIT */
}

Step 6 — Sender Integration

/* Sender runnable (10ms task) */
void WheelSpeedSensor_SendFR(void)
{
    WheelSpeedDataType txData;

    /* Fill application data */
    txData.SpeedRPM = AcquireWheelSpeed_FR();

    /* Call E2E Profile 2 Protect — adds CRC-8-H2F + Counter */
    Std_ReturnType e2eResult = E2E_P02Protect(
        &E2E_P02_Config_WheelSpeedFR,
        &E2E_P02_ProtectState_WheelSpeedFR,
        (uint8*)&txData
    );

    if (e2eResult == E2E_E_OK) {
        /* Write protected data to RTE */
        Rte_Write_WheelSpeedFR_Port((const uint8*)&txData);
    } else {
        /* E2E configuration error — report to DEM */
        Dem_ReportErrorStatus(WS_FR_E2E_ConfigError, DEM_EVENT_STATUS_FAILED);
    }
}

Step 7 — Document DataIDList Configuration Management

For automotive functional safety ISO 26262 ASIL D E2E certification, the safety case must document how DataIDList values are managed through the ECU software lifecycle — including how mismatches are prevented during ECU variant management, how DataIDList updates (if any) are handled during reprogramming, and how the correct values are verified during production EOL testing.

16. ISO 26262 Compliance and ASIL D Analysis for AUTOSAR E2E Profile 2

AUTOSAR E2E Profile 2 satisfies the communication protection requirements of automotive functional safety ISO 26262 ASIL D E2E when correctly deployed and when a project-specific safety analysis demonstrates that the residual error probability meets the ASIL D quantitative requirement.

Fault Coverage Summary

Fault Type	Detection Mechanism	Residual Error Rate
Data corruption (bit flips)	CRC-8-H2F (Hamming distance 6 for ≤119 data bits)	~2⁻⁸ = 1/256 for errors outside HD guarantee
Message loss	Counter delta evaluation (OKSOMELOST / WRONGSEQUENCE)	Near-zero (counter + CRC together)
Message repetition	Counter delta = 0 → REPEATED status	Near-zero (1/15 if counter wraps simultaneously)
Message delay / timeout	Counter freeze detection + NONEWDATA status	Application-dependent (timeout threshold)
Masquerade / insertion	DataIDList rotating key (never transmitted)	~1/256 per transmission (attacker must guess correct DataIDList byte)
Wrong sequence	Counter delta > MaxDeltaCounter → WRONGSEQUENCE	Near-zero

Profile 2 vs Profile 1 — Safety Comparison for ISO 26262

For automotive functional safety ISO 26262 ASIL D E2E analysis, AUTOSAR E2E Profile 2 provides objectively better fault coverage than Profile 1 in two dimensions: the CRC-8-H2F polynomial achieves Hamming distance 6 versus Profile 1’s Hamming distance 4 (for messages up to 119 data bits), and the rotating DataIDList provides stronger masquerade protection than Profile 1’s static or alternating Data ID. Projects requiring the most rigorous ASIL D safety case with the smallest residual error argument should prefer AUTOSAR E2E Profile 2 over Profile 1.

17. Real-World Automotive Use Cases for AUTOSAR E2E Profile 2

AUTOSAR E2E Profile 2 is widely deployed across safety-critical automotive control systems. Its combination of superior CRC performance and stronger masquerade protection makes it the preferred choice for high-criticality signals in AUTOSAR E2E CAN FlexRay communication protection deployments.

Electronic Stability Control (ESC) — Sensor Fusion Signals

ESC systems require lateral acceleration, yaw rate, and wheel speed signals — all typically ASIL C–D. These signals are transmitted via CAN between sensor ECUs and the ESC controller. AUTOSAR E2E Profile 2 is commonly specified for these interfaces by European OEMs due to its superior masquerade protection, which prevents a failed sensor from being misidentified as a functioning one. The unique DataIDList for each sensor channel ensures that data from a faulty yaw rate sensor cannot be mistaken as valid lateral acceleration data by the ESC controller.

Brake-by-Wire — Pedal Sensor to Brake Controller

Next-generation brake-by-wire systems (used in EVs and hybrid vehicles) rely entirely on electronic signals for brake actuation. The brake pedal position sensor signal is classified ASIL D. AUTOSAR E2E Profile 2 on the CAN or FlexRay interface between the pedal sensor ECU and the brake hydraulic controller provides the CRC-8-H2F fault detection and rotating DataIDList masquerade protection required to demonstrate ASIL D communication integrity for this safety-critical interface.

FlexRay Safety-Critical Chassis Communication

FlexRay networks — common in premium vehicle platforms for their deterministic timing and higher bandwidth — carry safety-critical chassis signals including active suspension control, active torque vectoring, and integrated chassis dynamics data. AUTOSAR E2E Profile 2 is specifically listed as appropriate for FlexRay in the AUTOSAR specification (“only for CP”), making it a natural choice for FlexRay-based safety communication alongside Profile 4 (for longer FlexRay frames). For short FlexRay frames ≤ 256 bytes, Profile 2 provides excellent efficiency.

Cross-ECU Safety Signal Exchange in Multi-Core Architectures

Modern high-end automotive microcontrollers implement multiple processing cores with AUTOSAR’s memory and time protection mechanisms. In these systems, safety-relevant data exchanged between ASIL D and QM software components — even within the same ECU — is protected using AUTOSAR E2E Profile 2 on the intra-ECU communication path. This prevents a QM software defect from corrupting safety-critical data that a higher-integrity component depends upon.

18. AUTOSAR E2E Profile 2 vs Profile 1 — Detailed Technical Comparison

Engineers frequently need to choose between AUTOSAR E2E Profile 2 and Profile 1 for CAN-based safety-critical interfaces. This section provides a definitive technical comparison to support that decision.

Criterion	AUTOSAR E2E Profile 1	AUTOSAR E2E Profile 2	Winner
CRC Polynomial	CRC-8-SAE J1850 (0x1D) Start/XOR: 0x00	CRC-8-H2F (0x2F) Start/XOR: 0xFF	🏆 Profile 2 (better HD)
Hamming Distance	HD=4 for ≤119 data bits	HD=6 for ≤119 data bits	🏆 Profile 2
Data ID Mechanism	Static 16-bit DataID with 4 modes (BOTH/ALT/LOW/NIBBLE)	16-entry rotating DataIDList, never transmitted	🏆 Profile 2 (stronger masquerade protection)
Counter Range	4-bit (0–14)	4-bit (0–14)	🤝 Equal
Header Overhead	2 bytes (configurable position)	2 bytes (fixed position)	🤝 Equal
Header Position Flexibility	Fully configurable (CRCOffset, CounterOffset)	Fixed (Byte 0 = CRC, Byte 1 low nibble = counter)	🏆 Profile 1 (retrofit-friendly)
Max Data Length	240 bits (30 bytes)	2048 bits (256 bytes)	🏆 Profile 2
Bus Support	CAN, CAN FD (short), FlexRay	CAN, CAN FD, FlexRay (CP only)	🤝 Equal (both CP only for Profile 2)
Legacy Compatibility	Pre-AUTOSAR history; widest OEM support	AUTOSAR R3.1 onward; widely adopted	🏆 Profile 1 (more legacy deployments)
Configuration Complexity	Moderate (4 DataIDModes to choose from)	Moderate (DataIDList generation methodology)	🤝 Comparable
ISO 26262 ASIL D Suitability	Yes (with safety analysis)	Yes (stronger baseline)	🏆 Profile 2 (stronger safety argument)

Decision Recommendation

Choose AUTOSAR E2E Profile 2 when:

Starting a new design with no legacy CAN message layout constraints
The OEM specifies Profile 2 in their supplier interface requirements
Maximum masquerade protection is required (rotating DataIDList)
Better Hamming distance is needed to support the ASIL D safety case
Data elements exceed 30 bytes (Profile 2 supports up to 256 bytes)

Choose Profile 1 when:

Retrofitting E2E protection into an existing CAN message layout where the header position cannot be changed to Byte 0
The OEM specifies Profile 1 (many established OEM programs still mandate Profile 1)
The toolchain or legacy E2E implementation already supports only Profile 1

19. Gateway Handling for AUTOSAR E2E Profile 2

Gateway handling is one of the most complex integration scenarios for AUTOSAR E2E Profile 2 in multi-domain vehicle architectures. When a Profile 2-protected message travels through a gateway (e.g., from a CAN-connected sensor ECU to a FlexRay-connected domain controller), the gateway must handle the E2E protection correctly to maintain end-to-end integrity.

Transparent Forwarding (No Protocol Change)

If the gateway simply forwards the raw CAN frame onto another CAN segment without changing the message format, the E2E protection is naturally transparent. The CRC, counter, and data bytes are forwarded unchanged. The ultimate receiver’s E2E_P02Check() will succeed as if communicating directly with the original sender. This is the simplest gateway scenario and requires no special E2E handling in the gateway ECU.

Protocol Translation Gateway (CAN to FlexRay or CAN to Ethernet)

When a gateway translates a message between different bus protocols (e.g., CAN Frame → FlexRay PDU), it has two options:

Option A — E2E Passthrough: The gateway extracts the raw byte payload (including the E2E header) from the CAN frame and places it verbatim into the FlexRay PDU. The counter, CRC, and DataIDList semantics are fully preserved. The ultimate receiver can perform E2E_P02Check() against the same DataIDList configuration. This is the preferred approach for end-to-end safety guarantees.
Option B — E2E Re-Protect: The gateway performs E2E_P02Check() on the received CAN message and then E2E_P02Protect() on the outgoing FlexRay PDU — potentially with a different DataIDList for the new segment. This breaks the “end-to-end” property (the protection no longer spans from original sender to ultimate receiver) but may be necessary if the FlexRay segment has different DataIDList requirements. In this case, the safety analysis must treat the gateway as a safety-relevant component that maintains protection integrity.

The critical rule: a gateway must never silently discard or ignore the E2E protection header when forwarding safety-critical data. Doing so would result in the receiving ECU’s E2E_P02Check() function always reporting CRC errors (because it attempts to verify a non-existent E2E header), degrading the system to INVALID state — or worse, if the gateway reconstructs dummy E2E headers without proper CRC or DataIDList, masking a real data corruption fault.

20. Advantages of AUTOSAR E2E Profile 2

AUTOSAR E2E Profile 2 offers a compelling set of technical advantages for automotive embedded systems engineers and functional safety specialists:

1. Superior CRC Polynomial (CRC-8-H2F, HD=6): The E2E Profile 2 CRC-8-H2F 0x2F polynomial provides Hamming distance 6 for automotive-length messages — guaranteeing detection of all 5-bit error combinations. This is a substantial improvement over Profile 1’s HD=4, significantly strengthening the residual error probability argument in the ASIL D safety case.

2. Strongest Masquerade Protection in the 8-bit CRC Profile Family: The rotating AUTOSAR E2E Profile 2 DataIDList mechanism — with 16 distinct message keys cycling through every 15 transmissions — provides fundamentally stronger masquerade protection than any static or alternating Data ID scheme. Since the DataIDList is never transmitted, an eavesdropper analyzing bus traffic cannot reconstruct the keys used in the CRC computation.

3. Larger Maximum Data Length (256 Bytes): At 256 bytes maximum, AUTOSAR E2E Profile 2 is applicable not only to classic CAN (8-byte payloads) but also to longer CAN FD frames (up to 64 bytes), FlexRay frames (up to 254 bytes), and moderate-length intra-ECU data structures. This broad coverage with a compact 2-byte overhead makes Profile 2 one of the most versatile profiles in the E2E library for AUTOSAR E2E CAN FlexRay communication protection.

4. Fixed Header Layout Eliminates Configuration Errors: The fixed CRC at Byte 0 and counter at low nibble of Byte 1 eliminates the category of integration errors caused by mismatched CRCOffset/CounterOffset parameters — a known source of subtle bugs in Profile 1 multi-supplier programs. In a Profile 2 deployment, both sender and receiver always know exactly where to find the header fields.

5. Wide OEM and Toolchain Adoption: AUTOSAR E2E Profile 2 is the default profile specified by many European automotive OEMs, and is fully supported by all major AUTOSAR toolchains (Vector DaVinci, ETAS RTA-CAR, EB tresos). The AUTOSAR SWS_E2ELibrary’s dedicated chapter on DataIDList generation reflects the maturity and thoroughness of its specification.

6. ASIL D Over QM Stack: Like all E2E profiles, AUTOSAR E2E Profile 2 enables automotive functional safety ISO 26262 ASIL D E2E communication protection over a QM-rated communication stack, eliminating the cost and complexity of certifying the entire CAN/FlexRay stack to ASIL D.

21. Limitations and Challenges of AUTOSAR E2E Profile 2

Despite its advantages, engineers should be aware of these limitations when deploying AUTOSAR E2E Profile 2:

1. CP-Only (No Adaptive Platform Support): AUTOSAR E2E Profile 2 is defined exclusively for the AUTOSAR Classic Platform. It is not included in the AUTOSAR Adaptive Platform E2E Protocol Specification. Projects migrating to AUTOSAR AP or using hybrid CP+AP architectures must use different profiles (Profile 6, 7, or 22) for the AP segments.

2. DataIDList Configuration Management Complexity: The AUTOSAR E2E Profile 2 DataIDList introduces a new system-level artifact — 16 bytes per protected signal — that must be managed across the vehicle software lifecycle. DataIDList mismatches between sender and receiver are silent failures at design time but catastrophic at runtime (100% CRC errors for affected counter positions). Robust configuration management and EOL verification are mandatory.

3. Fixed Header Position May Not Fit All Legacy Layouts: Unlike Profile 1 where the CRC and counter can be placed at arbitrary positions, Profile 2 always places CRC at Byte 0 and counter in the low nibble of Byte 1. This fixed layout is ideal for new designs but cannot be used to retrofit E2E protection into existing CAN message layouts where Byte 0 is already occupied by application signal data without changing the message format.

4. 4-Bit Counter Limitation: The 4-bit counter (0–14) wraps every 15 transmissions. As with Profile 1, this is adequate for most automotive cycle rates but may need careful analysis for very high-frequency signals (e.g., 1ms cycle rate) where counter reuse occurs every 15ms.

5. Residual Error Rate Requires Project-Specific Analysis: Despite Profile 2’s superior Hamming distance, the residual error rate for automotive functional safety ISO 26262 ASIL D E2E compliance must still be demonstrated through project-specific safety analysis. The 8-bit CRC still has a 1/256 residual error probability for error patterns beyond its Hamming distance guarantee, and this must be shown to meet the ASIL D quantitative requirement for the specific network.

22. Testing AUTOSAR E2E Profile 2 — Fault Injection Strategy

A comprehensive test strategy for AUTOSAR E2E Profile 2 must cover all fault detection mechanisms. The following fault injection test cases are required for automotive functional safety ISO 26262 ASIL D E2E compliance testing:

Test ID	Fault Injected	Expected E2E Status	Expected SW-C Reaction
TC-P2-001	Single bit flip in signal data byte (e.g., Byte 3)	E2E_P02STATUS_ERROR (CRC-8-H2F mismatch)	Safe default; DTC logged
TC-P2-002	5-bit burst error in signal bytes	E2E_P02STATUS_ERROR (HD=6 should catch all ≤5-bit errors)	Safe default; DTC logged
TC-P2-003	Corrupt CRC byte (flip bit 4)	E2E_P02STATUS_ERROR	Safe default
TC-P2-004	Drop 1 consecutive message	E2E_P02STATUS_OKSOMELOST (delta=2)	Use data; log some-lost DTC
TC-P2-005	Drop 3 consecutive messages	E2E_P02STATUS_WRONGSEQUENCE (delta=4 > MaxDelta=1)	Safe default; DTC
TC-P2-006	Replay same frame twice (counter frozen)	E2E_P02STATUS_REPEATED	Discard; repetition DTC
TC-P2-007	Sender stops (timeout beyond MaxDelta cycles)	E2E_P02STATUS_NONEWDATA	Safe default; timeout DTC
TC-P2-008	Masquerade: inject frame with wrong DataIDList byte (correct counter, wrong CRC)	E2E_P02STATUS_ERROR	Safe default; DTC
TC-P2-009	Counter rollback (send counter=5 after counter=10)	E2E_P02STATUS_WRONGSEQUENCE	Safe default
TC-P2-010	Receiver ECU reset mid-stream → INIT state	E2E_P02STATUS_INITIAL	Do not use data until first OK
TC-P2-011	Sustained 3+ errors → INVALID, then 5+ OK → VALID recovery	INVALID → VALID after MinOkStateInvalid OK	Safe default during INVALID; normal during VALID
TC-P2-012	DataIDList mismatch between sender/receiver (misconfig simulation)	E2E_P02STATUS_ERROR (permanent, all transmissions)	INVALID state quickly; persistent DTC

23. Tools and Configuration Support for AUTOSAR E2E Profile 2

All major AUTOSAR toolchains and testing platforms provide comprehensive support for AUTOSAR E2E Profile 2:

Vector DaVinci Developer / Configurator Pro: Full Profile 2 support including DataIDList configuration UI, state machine parameter setup, E2E Transformer and E2E Protection Wrapper code generation. CANoe integration allows live Profile 2 CRC-8-H2F decoding and fault injection on CAN/FlexRay buses.

ETAS RTA-CAR (Application Note 06 — E2E Configuration): ETAS provides a dedicated E2E configuration guide for Profile 2 covering DataIDList setup, CRC module activation (Crc8H2F must be enabled), and Protection Wrapper generation. Supports both E2E Transformer (R4.2+) and legacy protection wrapper approaches.

Elektrobit (EB) tresos Studio: AUTOSAR configuration tool with full Profile 2 support. Generates AUTOSAR-compliant E2E_P02ConfigType initialization code from the tool’s GUI configuration.

Python autosar-e2e Library: The open-source Python library at autosar-e2e.readthedocs.io implements E2E Profile 2 CRC-8-H2F 0x2F polynomial calculations (via e2e.crc.calculate_crc8_h2f()) and full Profile 2 protect/check functions (e2e.p02.e2e_p02_protect() and e2e.p02.e2e_p02_check()). This library is ideal for building Python-based test harnesses that validate AUTOSAR E2E Profile 2 implementations in ECU HIL or SIL environments.

dSPACE VEOS / SCALEXIO: Hardware-in-the-loop platforms supporting AUTOSAR E2E Profile 2 fault injection testing (counter manipulation, CRC corruption, DataIDList mismatch simulation). These platforms are essential for automotive functional safety ISO 26262 ASIL D E2E verification testing.

MATLAB/Simulink AUTOSAR Blockset: Supports Profile 2 in model-based development and SiL testing workflows, enabling simulation of Profile 2-protected communication before target code generation.

24. Frequently Asked Questions About AUTOSAR E2E Profile 2

Q1: What is the CRC polynomial used in AUTOSAR E2E Profile 2?

AUTOSAR E2E Profile 2 uses the CRC-8-H2F polynomial 0x2F (x⁸+x⁵+x³+x²+x+1), with both start value and XOR output value equal to 0xFF. This polynomial is also known as CRC-8/AUTOSAR in non-AUTOSAR literature. The AUTOSAR CRC Library implements this as Crc_CalculateCRC8H2F(). The H2F designation simply refers to the hexadecimal value 0x2F of the generator polynomial coefficient byte.

Q2: What is the AUTOSAR E2E Profile 2 DataIDList and why is it important?

The AUTOSAR E2E Profile 2 DataIDList is a pre-shared array of 16 unique 8-bit bytes that function as a rotating message key. For each transmission, the specific byte used in the CRC-8-H2F computation is selected by the current counter value as an array index. This rotating key mechanism is never transmitted on the bus — making it a virtual secret that provides stronger masquerade protection than Profile 1’s static or alternating Data ID. A DataIDList mismatch between sender and receiver will cause CRC failures for the affected counter positions, making correct configuration and management of DataIDList values critical in production programs.

Q3: Why does AUTOSAR E2E Profile 2 use a 16-entry DataIDList if the counter only goes up to 14?

The counter in AUTOSAR E2E Profile 2 uses values 0–14 (15 entries), not 0–15, because value 15 (0xF) is reserved for the initialization/invalid state. The DataIDList has 16 entries (indices 0–15) to match the 4-bit counter’s theoretical range. In practice, DataIDList[15] is never accessed during normal operation since the counter never reaches 15. It should still be populated with a valid byte value in the configuration (not left uninitialized) to avoid undefined behavior if the counter somehow receives value 15 due to a fault.

Q4: Is AUTOSAR E2E Profile 2 available in AUTOSAR Adaptive Platform?

No. AUTOSAR E2E Profile 2 is defined exclusively for AUTOSAR Classic Platform (CP). The AUTOSAR Adaptive Platform (AP) E2E Protocol Specification does not include Profile 2. For AUTOSAR AP safety-critical communication over SOME/IP, Profiles 6, 7, or 22 should be used depending on data size and communication pattern. In hybrid CP+AP architectures, Profile 2 can still be used on the CP side with a gateway handling the protocol translation to the AP-side profiles.

Q5: How do I verify that my DataIDList is configured correctly on both sender and receiver?

The most reliable verification method is EOL (End-of-Line) production testing where a test tool sends E2E Profile 2-protected messages with known counter values and checks that the receiving ECU accepts them (counter-and CRC-correct messages). If any counter values consistently produce CRC errors, that counter’s DataIDList entry is mismatched. During integration testing, Vector CANoe with the AUTOSAR E2E plugin can decode live CAN traffic and display the expected CRC for a given DataIDList — allowing direct comparison. Automated regression tests should include TC-P2-012 (DataIDList mismatch detection) to catch misconfigurations early.

Q6: Can I use AUTOSAR E2E Profile 2 and Profile 1 on the same ECU simultaneously?

Yes. The AUTOSAR E2E Library is designed as a static library with separate configuration structures and state instances for each profile and each data element. An ECU can simultaneously use Profile 1 for some signals (e.g., legacy interfaces with fixed CRCOffset requirements) and AUTOSAR E2E Profile 2 for others (e.g., new interfaces where stronger masquerade protection is required). Both Crc_CalculateCRC8() (for Profile 1) and Crc_CalculateCRC8H2F() (for Profile 2) must be enabled in the Crc module configuration.

Q7: What happens if the AUTOSAR E2E Profile 2 state machine enters INVALID state during vehicle operation?

When the AUTOSAR E2E Profile 2 state machine enters INVALID, the application SW-C is expected to apply a safe default value (e.g., a previously known-good value, a mid-range fallback, or a predefined safe state) and report a Diagnostic Trouble Code (DTC) via the Dem module. The vehicle function associated with the invalid signal should enter a degraded operating mode (e.g., ESC reduced intervention, EPS in limp-home mode) as defined by the system safety concept. The state machine will automatically attempt recovery once MinOkStateInvalid consecutive valid receptions are received, but the safety function must remain in degraded mode until the state returns to VALID.

Q8: How does AUTOSAR E2E Profile 2 handle 1:N communication (one sender, multiple receivers)?

In 1:N communication with AUTOSAR E2E Profile 2, the sender transmits to all receivers using the same CRC and counter. Each receiver maintains its own independent E2E_P02CheckStateType instance with its own state machine. All receivers must be configured with the identical AUTOSAR E2E Profile 2 DataIDList — since the CRC is computed with the DataIDList on the sender side and verified using the same list on each receiver side. Each receiver independently tracks its own counter history and state machine status. A receiver that joins mid-stream (e.g., after an ECU reset) starts in INIT state and must accumulate MinOkStateInit consecutive OK receptions before its local state machine reaches VALID, regardless of the other receivers’ states.

25. Conclusion

AUTOSAR E2E Profile 2 stands as one of the most technically refined safety communication protocols in the AUTOSAR Classic Platform specification. By combining the superior E2E Profile 2 CRC-8-H2F 0x2F polynomial — which achieves Hamming distance 6 for automotive-length CAN messages — with the innovative rotating AUTOSAR E2E Profile 2 DataIDList mechanism that provides stronger masquerade protection than any static Data ID scheme, Profile 2 delivers a qualitatively higher safety assurance level than its predecessor Profile 1 within the same compact 2-byte header footprint.

For engineers implementing AUTOSAR E2E CAN FlexRay communication protection in new automotive ECU programs, AUTOSAR E2E Profile 2 should be the default choice for safety-critical CAN and FlexRay interfaces where the fixed header layout at Byte 0 is acceptable — which is the case for virtually all new designs. Its fixed, unambiguous header structure eliminates a category of configuration errors, its superior CRC polynomial strengthens the automotive functional safety ISO 26262 ASIL D E2E safety argument, and its rotating DataIDList provides a level of masquerade protection that makes it genuinely challenging to defeat without access to the ECU firmware.

Mastering AUTOSAR E2E Profile 2 — from the CRC-8-H2F polynomial mathematics to the DataIDList generation methodology, from the precise protect/check algorithm to the state machine thresholds and fault injection test requirements — is a fundamental competency for any automotive embedded systems engineer working on ASIL D safety-critical ECU development.

📚 AUTOSAR E2E Profile Series — Continue Learning:

References

AUTOSAR — Specification of SW-C End-to-End Communication Protection Library (AUTOSAR_SWS_E2ELibrary, Document ID 428, Release 4.3.1) — Chapter 13: Usage and generation of DataIDLists for E2E Profile 2
AUTOSAR — E2E Protocol Specification (AUTOSAR_PRS_E2EProtocol), Releases R3.1 through R24-11
AUTOSAR — Requirements on E2E Communication Protection (AUTOSAR_SRS_E2E, Document ID 651)
ISO 26262:2018 — Road Vehicles — Functional Safety, Part 6: Software Level
AUTOSAR — Specification of CRC Routines (AUTOSAR_SWS_CRCLibrary, Document ID 016)
autosar-e2e Python Library Documentation: autosar-e2e.readthedocs.io
ETAS RTA-CAR Application Note 06 — E2E Configuration Guide

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AUTOSAR E2E Profile 2 Explained: CRC16, DataID, and CAN Communication Protection

Table of Contents

1. What is AUTOSAR E2E Profile 2?

2. History and Background of AUTOSAR E2E Profile 2

3. AUTOSAR E2E Profile 2 in the AUTOSAR Architecture

4. AUTOSAR E2E Profile 2 — Complete Technical Specifications

5. AUTOSAR E2E Profile 2 Header Layout and Bit-Level Structure

6. E2E Profile 2 CRC-8-H2F Polynomial 0x2F — Deep Dive

The H2F Polynomial

Why CRC-8-H2F is Superior to CRC-8-SAE J1850 for Automotive Messages

CRC-8-H2F and Independence from Bus CRC

CRC-8-H2F Computation Example

7. Sequence Counter Mechanism in AUTOSAR E2E Profile 2

Counter Behavior

Counter as Fault Detection

8. AUTOSAR E2E Profile 2 DataIDList — Complete Explanation

What is the DataIDList?

Why the Rotating DataIDList Provides Stronger Masquerade Protection

AUTOSAR E2E Profile 2 DataIDList Is Implicit (Never Transmitted)

9. AUTOSAR E2E Profile 2 DataIDList Generation Methodology

Requirements for a Valid DataIDList

DataIDList Generation Approaches

Approach A — Systematic from a Master Data ID (AUTOSAR Chapter 13 Method)

Approach B — Cryptographically Random Generation

Approach C — OEM-Specified Fixed Values

DataIDList Generation Pitfalls (From AUTOSAR Chapter 13 Examples)

10. E2E_P02Protect() — Sender Algorithm Step by Step

Function Signature

Protect Algorithm — Step by Step

Complete E2E_P02Protect() Code Example

11. E2E_P02Check() — Receiver Algorithm Step by Step

Function Signature

Check Algorithm — Step by Step

Complete Receiver Handling Code Example for AUTOSAR E2E Profile 2

12. AUTOSAR E2E Profile 2 State Machine

State Machine Overview

State Machine Configuration Parameters for AUTOSAR E2E Profile 2

13. E2E_P02ConfigType — All Parameters Explained

Example Configuration — ABS Wheel Speed FR (CAN, 10ms, ASIL D)

14. E2E_P02CheckStatusType — Status Codes and Application Handling

15. Practical Implementation Guide for AUTOSAR E2E Profile 2

Step 1 — Obtain or Generate the DataIDList

Step 2 — Enable CRC-8-H2F in the Crc Module

Step 3 — Configure the E2E_P02ConfigType

Step 4 — Choose E2E Transformer or Protection Wrapper

Step 5 — Initialize State Structures

Step 6 — Sender Integration

Step 7 — Document DataIDList Configuration Management

16. ISO 26262 Compliance and ASIL D Analysis for AUTOSAR E2E Profile 2

Fault Coverage Summary

Profile 2 vs Profile 1 — Safety Comparison for ISO 26262

17. Real-World Automotive Use Cases for AUTOSAR E2E Profile 2

Electronic Stability Control (ESC) — Sensor Fusion Signals

Brake-by-Wire — Pedal Sensor to Brake Controller

FlexRay Safety-Critical Chassis Communication

Cross-ECU Safety Signal Exchange in Multi-Core Architectures

18. AUTOSAR E2E Profile 2 vs Profile 1 — Detailed Technical Comparison

Decision Recommendation

19. Gateway Handling for AUTOSAR E2E Profile 2

Transparent Forwarding (No Protocol Change)

Protocol Translation Gateway (CAN to FlexRay or CAN to Ethernet)

20. Advantages of AUTOSAR E2E Profile 2

21. Limitations and Challenges of AUTOSAR E2E Profile 2

22. Testing AUTOSAR E2E Profile 2 — Fault Injection Strategy

23. Tools and Configuration Support for AUTOSAR E2E Profile 2

24. Frequently Asked Questions About AUTOSAR E2E Profile 2

25. Conclusion

References

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