Diagnostic Trouble Code (DTC) Information

Diagnostic trouble code (DTC) information CEM-U010400

Condition
The control modules communicate with each other for exchange of information in a network via a standardized serial communication procedure - CAN (Controller Area Network).
The diagnostic trouble code (DTC) is stored if the control module detects that:
- Interrupted or missing communication with the Forward Sensing Module (FSM).
The control module's test for the diagnostic trouble code (DTC) starts in the event of:
- Ignition switch position II.

Note! The control module can only detect the fault once the test has been started and the diagnostic trouble code (DTC) is stored when the conditions are met. The diagnostic trouble code (DTC) indicates a fault in the communication across the CAN network and does not isolate an individual node. Do not replace the central electronic module (CEM) unless fault-tracing indicates a damaged control module.





Substitute value
- None.

Possible source
- Voltage supply to the Forward Sensing Module (FSM) missing.
- Open-circuit in the ground lead to the Forward Sensing Module (FSM).
- Contact resistance in the terminals.
- Open-circuit or short-circuit in the wiring for the control area network (CAN).
- The Forward Sensing Module (FSM) is not intended for this vehicle, for example, it is a used control module with other software/hardware.

Hint: If several diagnostic trouble codes for communication errors with other control modules in the high-speed network are stored in the Central electronic module (CEM), this indicates some common problem in the CAN-network (see wiring diagram).

Fault symptom[s]
- Adaptive cruise control; No Functionality
- Forward collision warning; No Functionality
- Collision avoidance driver support; No Functionality