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Test C: The Differential Electronic Module (DEM) Does Not Respond To The Scan Tool

PINPOINT TEST C: THE DIFFERENTIAL ELECTRONIC MODULE (DEM) DOES NOT RESPOND TO THE SCAN TOOL


C1-C2:






C3-C4:






Normal Operation
The DEM communicates with the scan tool through the high speed controller area network (HS-CAN). Circuits 1908 (WH) (HS-CAN +) and 1909 (BK) (HS-CAN -) provide the network connection to the DEM. The DEM shares the HS-CAN network with the powertrain control module (PCM), the transmission control module (TCM), the anti-lock brake system (ABS) module, the restraints control module (RCM) and the instrument cluster. Voltage for the DEM is provided by circuit 972 (BK/WH), and ground is provided by circuit 570 (BK).

Possible Causes
- Fuse
- Circuit 570 (BK) open
- Circuit 972 (BK/WH) open
- Circuit 1908 (WH) open (MS-CAN +)
- Circuit 1909 (BK) open (MS-CAN -)
- DEM