- X63/4 (CAN databus adapter connector, 2-pin)
- Test connectors and wiring for CAN of engine compartment CAN control modules.
- Control unit
Communication with ECU required ( Measuring system )
2. Check the CAN communication with control unit A1 (Instrument cluster).
Warning!Communication with ECU required.
3. Central CAN test
Warning!Communication with ECU required.
Part 1
No CAN message was received from control unit N22 (AAC [KLA] control and operating unit).
Possible cause:
- Check the CAN communication with control unit N22/1 (AAC [KLA] control unit).
- Interior CAN bus
Affected functions:
- CAN Communication
- Automatic transmission Function
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Test 1: Engine compartment CAN test
Test 2: Check the CAN communication with control unit N22 (AAC [KLA] control and operating unit).
Test 3: Interior CAN check
1. Engine compartment CAN test
Test 1.1: Procedure in case of CAN faults
Test 1.2: Evaluation of CAN fault codes
Test 1.3: Further CAN test options
1.1. Procedure in case of CAN faults
Test 1.1.1: How do I quickly reach my goal?
Test 1.1.2: General test information
Test 1.1.3: General CAN fundamentals
Test 1.1.4: Possible aids and their usage
1.1.1. How do I quickly reach my goal?
How do I quickly reach my goal?First call up menu item 'Evaluation of CAN fault codes' in case of CAN timeout fault codes and communication
errors.The resulting tests must be performed.Menu item 'Further CAN test options' should only be called up if the above-specified tests do not
produce the desired result.Note:Menu item 'General test information' can be called up for an explanation of the different CAN fault types.
1.1.2. General test information
Notes on CAN fault codes:CAN timeout fault
- A CAN timeout fault code is set due to the absence of a CAN input signal.The cause of this may be not only the transmitter control unit, but
also the CAN networking.
- For example:No CAN message was received from control unit A.
Bus OFF fault
- A Bus OFF fault code is set, when the control unit cannot send a certain amount of messages to the CAN bus or the messages are
incomplete.The control unit then switches off for a short time from CAN bus.
- For example:CAN controller: CAN bus OFF
