Diagnostic Trouble Code (DTC) Information

Diagnostic trouble code (DTC) information CPM-U030000

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 Central electronic module (CEM) regularly transmits messages on the CAN network. These messages contain information about which signal configuration ID applies to the vehicle. The control modules on the CAN network have the same signal configuration ID so that they can communicate with each other. The control module compares its configuration ID with the signal configuration transmitted on the control area network (CAN) by the central electronic module (CEM).
The diagnostic trouble code (DTC) is stored if the control module detects that:
- The control module's configuration ID differ from the ID that the Central electronic module (CEM) transmits.
The control module's test for the diagnostic trouble code (DTC) starts in the event of:
- Heater started.

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.





Substitute value
- Control module shuts itself off ("bus-off").
- Heater's function blocked.

Possible source
- Incorrect configuration parameter. Combustion preheater module (CPM) not intended for this car, e.g., used control module with other hardware/software.
- Open-circuit in the CAN cables between the control module and the Central Electronic Module (CEM).

Fault symptom[s]
- Poor heating in compartment
- Parking heater does not operate