Pinpoint Test B: No Communication with the Driver Seat Module (DSM): Testing

2009 Ford Fusion SEL, 3.0 1, FWDSECTION Testing
WARNING: This page is about a different car, the 2005 Mercury Montego, 2005 Ford Freestyle, and 2005 Ford Five Hundred. However, it is still accessible from the selected car via links, so may be relevant.
  1. B1 CHECK THE DSM VOLTAGE SUPPLY CIRCUITS FOR AN OPEN 
    • Key in OFF position.
    • Disconnect: DSM C341a.
    • Disconnect: DSM C341c.
    • Measure the voltage between the DSM C341a-2, circuit 566 (DG), harness side and ground; and between the DSM C341c-1, circuit 956 (OG/LG), harness side and ground.
      Fig 1: Measuring Voltage Between DSM C341A-2 Circuit 566 (DG)
      G03993024Courtesy of FORD MOTOR CO.
    • Are the voltages greater than 10 volts? 
    • Yes  : GO to B2.
    • No  : REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.
  2. B2 CHECK THE DSM GROUND CIRCUIT FOR AN OPEN 
    • Measure the resistance between the DSM C341a-1, circuit 1205 (BK), harness side and ground; and between the DSM C341c-13, circuit 1203 (BK/LB), harness side and ground.
      Fig 2: Measuring Resistance Between DSM C341A-1 Circuit 1205 (BK)
      G03993025Courtesy of FORD MOTOR CO.
    • Are the resistances less than 5 ohms? 
    • Yes  : REFER to MODULE COMMUNICATIONS NETWORK to continue communication diagnosis.
    • No  : REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
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