Diagnostic Trouble Code (DTC) Information

Diagnostic trouble code (DTC) information CEM-U049900

Condition
The central electronic module (CEM) is continuously supplied with the necessary information from the phone module (PHM). The central electronic module (CEM) checks information coming from the phone module (PHM).
The diagnostic trouble code (DTC) is stored if the control module detects that:
- The transmitting control module sends an incorrect value to the central electronic module (CEM).
The control module's test for the diagnostic trouble code (DTC) starts in the event of:
- All ignition positions.

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
- None.

Possible source
- Incorrect software in the phone module (PHM).
- Incorrect software in the central electronic module (CEM).

Hint: If several diagnostic trouble codes (DTCs) are stored in the central electronic module (CEM) for communication faults with other control modules in the low speed network, this indicates a common fault in the Control area network, see the wiring diagram. Do not replace the Central electronic module (CEM) unnecessarily.

Fault symptom[s]
- Volvo On Call/Does not work
- Volvo On Call/Other Volvo On Call problems