Pinpoint Test B: No Communication With The Driver Door Module (DDM)

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.

B1 CHECK CIRCUITS 29-AJ80 (OG) AND 29S-AJ86 (OG/BU) FOR VOLTAGE
- Key in OFF position.
- Disconnect: DDM C501a.
- Key in ON position.
- Measure the voltage between DDM C501a-11, circuit 29-AJ80 (OG), harness side and ground; and between DDM C501a-12, circuit 29S-AJ86 (OG/BU), harness side and ground.
  
  Fig 1: Checking Circuits 29-AJ80 (OG) And 29S-AJ86 (OG/BU) For Voltage
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes : GO to B2.
- No : REPAIR the circuit in question. Test the system for normal operation.
B2 CHECK CIRCUITS 31-AJ80B (BK/OG) AND 91-AJ80 (BN/BU) FOR OPENS
- Key in OFF position.
- Measure the resistance between DDM C501a-7, circuit 91-AJ80 (BN/BU), harness side and ground; and between DDM C501a-8, circuit 31-AJ80B (BK/OG), harness side and ground.
  
  Fig 2: Checking Circuits 31-AJ80B (BK/OG) And 91-AJ80 (BN/BU) For Opens
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
- Yes : REFER to MODULE COMMUNICATIONS NETWORK .
- No : REPAIR the circuit(s) in question. Test the system for normal operation.