Communication Problems With The Engine Control Module (ECM): Information

• HINT: In the event of communication problems, the fault may exist in other parts of the communications network. The role of the central electronic module (CEM) is to control the communications network and to store diagnostic trouble codes (DTCs) in the event of communication problems between control modules. 

  If there are diagnostic trouble codes (DTCs) for communication problems stored for the brake control module (BCM) in the central electronic module (CEM), these must be fault traced first.

Were diagnostic trouble codes (DTCs) stored in the central electronic module (CEM)? 

• YES 

  OKAY:  Troubleshooting has been completed.

• NO 

  Refer to CHECKING DIAGNOSTIC TROUBLE CODES (DTCS) IN THE ENGINE CONTROL MODULE (ECM)