Faulty Communication

Faulty communication

Checking the wiring
The diagnostic trouble code (DTC) is stored if there is no communication between the engine control module (ECM) and the alternator control module (ACM). This may be due to a fault in the signal cable between the control modules or a damaged communication device in one or both of the control modules.

Hint: This diagnostic trouble code (DTC) can be stored if a generator (GEN) with an alternator control module (ACM) (charge regulator) not intended for LIN communication is installed.

Check the connector on the alternator control module (ACM). Check for contact resistance and oxidation.
Check the signal cable. Check for an open-circuit. Check for a short-circuit to ground. Check for a short-circuit to supply voltage.
Take readings between:
- Engine control module (ECM) #A46 (#A46) and alternator control module (ACM) #B2.

Hint: Another test to check the alternator's function is to perform Quick test of alternator function. Found in VIDA vehicle communication under Central electronic module (CEM).

Remedy as necessary.

Other information
- Connecting the breakout box, B5254T7 Connecting the Breakout Box, Engine Control Module (ECM)
- Signal specification, B5254T7 Signal Specification
- Checking wiring and terminals Checking Wiring and Terminals

Was a fault detected?

Yes - Fault-tracing information

No - Replacing the control module

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Replacing the control module
Try a new alternator control module (ACM).
Remedy as necessary.

Continue - Fault-tracing information

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Fault-tracing information




Information

Fault-tracing information
In case of this defect, troubleshooting is not followed by verification.
The information can be displayed again or the fault-tracing for this fault can be interrupted.

Do you want to view the information again?

Yes - Attempt New Test

No - FAULT FOUND

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Attempt New Test - Checking the wiring

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