Checking The Power Supply And Ground For The Differential Electronic Module (DEM)

Fig 1: Identifying Ignition OFF

Courtesy of VOLVO CARS CORPORATION

Ignition off.
Check that the fuse by the main fuse for the battery for the differential electronic module (DEM). Check that the fuse in the fuse box in the cargo compartment for the rear electronic module is intact.

Check the cable between the fuse and the power supply relay for the differential electronic module (DEM). Check for an open-circuit. Check for a short-circuit to ground. Check for a short-circuit to supply voltage.

Check the cable between the power supply relay for the differential electronic module (DEM) and the control module. Check for an open-circuit. Check for a short-circuit to ground. Check for a short-circuit to supply voltage.

Check the connectors and wiring for the differential electronic module (DEM) and the battery terminal. Check for contact resistance and oxidation. Check for loose connections.

If necessary, check the function of the power supply relay by moving it to another position.

Check the cable between the ground terminal and the differential electronic module (DEM). Check for an open-circuit. Check for a short-circuit to ground. Check for a short-circuit to supply voltage.

Check the ground terminal for the differential electronic module (DEM). Check for contact resistance and oxidation.

Other information:
- For AW50AWD and 4T65AWD 2003-, see DIFFERENTIAL ELECTRONIC MODULE (DEM), REPLACING
- For M66AWD 2004-, see DIFFERENTIAL ELECTRONIC MODULE (DEM), REPLACING .
- For TF-80SC 2005- see DIFFERENTIAL ELECTRONIC MODULE (DEM), REPLACING (2005-2008) .
- see CHECKING WIRING AND TERMINALS .
Fig 2: Identifying Ohm Meter
Courtesy of VOLVO CARS CORPORATION

Fig 3: Active On Demand Coupling Control Module
Courtesy of VOLVO CARS CORPORATION

Was a fault detected?

YES
Refer to CHECKING THE DIFFERENTIAL ELECTRONIC MODULE (DEM)
NO
Refer to CHECKING COMMUNICATION WITH THE DIFFERENTIAL ELECTRONIC MODULE (DEM)