Diagnostic Trouble Code (DTC) Information CEM-1B03
Condition
NOTE:
Only on vehicles with the function automatic start/stop of engine.
The Central electronic module (CEM) monitors the main battery relay, main battery diode and secondary battery relay and associated functionality.
The diagnostic trouble code is stored if the control module detects:
- Low power supply to the central electronic module (CEM).
- Incorrect value runs longer than 30 milliseconds.
The control module's test for the diagnostic trouble code (DTC) starts in the event of:
- At restart after auto stop (hot crank).
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
- Main battery relay jammed in closed position.
- Secondary battery relay jammed in open position.
- Damaged main battery diode.
- Damaged secondary battery relay.
- Damaged fuse for secondary battery.
- Open-circuit in the cable for the secondary battery.
- Secondary battery, poor capacity.
Fault symptom[s]
- Driving/Automatic start/stop of engine/Does not work
- Idling/Automatic start/stop of engine/Does not work