Diagnostic Trouble Code (DTC) Information

Diagnostic trouble code (DTC) information DEM-U012100

Condition
The Differential electronic module (DEM) is continually supplied with necessary information from the Brake control module (BCM) via controller area network (CAN) communication. The Brake control module (BCM) informs about the speed of each wheel, among other things. The Differential electronic module (DEM) checks the communication with the Brake control module (BCM).
The diagnostic trouble code (DTC) is stored if the control module detects that:
- No communication with the Brake control module (BCM).
- Incorrect value lasts longer than 5 seconds.
The control module's test for the diagnostic trouble code (DTC) starts in the event of:
- Ignition on.

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
- Reduced function of four-wheel drive.

Possible source

- Open-circuit in the communication cable.
- Short-circuit to ground in the communication cable.
- Short-circuit to supply voltage in the communication cable.
- Contact resistance or oxidation in the terminals.
- Look for the cause of the fault in the brake control module (BCM).

Fault symptom[s]
- MU, 4-wheel/all wheel drive/Does not work