Operation CHARM: Car repair manuals for everyone.

D - No Communication With Driver Door Module

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

D1 - Check Power Supply To Driver Door Module

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

Is voltage B+?

YES GO to D4.
NO GO to D2.

D2 - 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 D3.

D3 - 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).

D4 - 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 diagnostics in Computers and Control Systems to diagnose network concern.
NO SERVICE circuit 57 (BK) and or circuit 938 (BK/LG). RETEST vehicle. RETEST system.