Pinpoint Test D: No Communication With The Driver Seat Module (DSM)

WARNING: This page is about a different car, the 2005 Lincoln LS. However, it is still accessible from the selected car via links, so may be relevant.

D1 CHECK CIRCUIT 29-AH80 (OG/WH) AND 30-AH80 (RD) FOR VOLTAGE
- Key in OFF position.
- Disconnect: DSM C341b.
- Disconnect: DSM C341c.
- Key in ON position.
- Measure the voltage between the DSM C341b-4, circuit 30-AH80 (RD), harness side and ground and between the DSM C341c-10, circuit 29-AH80 (OG/WH), harness side and ground.
  
  Fig 1: Checking Circuit 29-AH80 (OG/WH) And 30-AH80 (RD) For Voltage
  Courtesy of FORD MOTOR CO.
- Are the voltages greater than 10 volts?
- Yes : GO to D2.
- No : REPAIR the supply circuit in question. CLEAR the DTCs. REPEAT the self-test.
D2 CHECK CIRCUITS 31-AH80 (BK) AND 91-AH80 (BN/WH) FOR AN OPEN
- Measure the resistance between the DSM C341b-3, circuit 31-AH80 (BK), harness side and ground; and between the DSM C341c-2, circuit 91-AH80 (BN/WH), harness side and ground.
  
  Fig 2: Checking Circuits 31-AH80 (BK) And 91-AH80 (BN/WH) For Open
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
- Yes : REFER to MODULE COMMUNICATIONS NETWORK .
- No : REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.