A: No Communication With Driver Door Module

Pinpoint Test A - No Communication With Driver Door Module (DDM)

A1 - Check Power Supply To Driver Door Module

- Disconnect driver door module connector C3.
- Using a voltmeter, measure for voltage at driver door module connector pin C3-4, circuit 517 (BK/W).

Is voltage B+?

YES GO to A4.
NO GO to A2.

A2 - Check Circuit 517 (BK/W) For Short To Ground

- Remove circuit breaker (20A) from fuse junction panel.
- Using an ohmmeter connected to ground, measure resistance at driver door module pin C34, circuit 517 (BK/W).

Is resistance less than 10 K ohms?

YES SERVICE circuit 517 (BK/W) for short to ground. RESTORE vehicle. RETEST system.
NO GO to A3.

A3 - Check Power Supply To Circuit Breaker (20A)

- Using a voltmeter, measure voltage at input cavity of circuit breaker (20A).

Is voltage B+?

YES SERVICE circuit 517 (BK/W) for open.
NO SERVICE power supply to circuit breaker (20A).

A4 - Check Ground Circuits

- Using an ohmmeter connected to ground, measure resistance at driver door module pins C1-15 and C1-4, circuit 57 (BK) Crown Victoria, Grand Marquis and pins C1-15, circuit 57 (BK), and C1-4, circuit 398 (BK/LG) Town Car.

Are both resistances less than 5 ohms?

YES GO to Information Bus in Computers and Control Systems to diagnose network concern.
NO SERVICE circuit 57 (BK) and or circuit 938. RESTORE vehicle. RETEST system.