Test A: No Communication With Driver's Door Module
NOTE:
Only vehicles equipped with keyless entry system have a Driver's Door Module (DDM).
- Turn ignition switch to LOCK position. Disconnect 4-pin Driver's Door Module (DDM) harness connector C520. Measure voltage between ground and DDM harness connector C520 terminal No. 4 (Black/White wire). See Fig 1 . If battery voltage does not exist, go to next step. If battery voltage exists, go to step 4 .
- Remove circuit breaker No. 7 (20-amp) from power distribution box. Measure resistance between ground and DDM harness connector C520 terminal No. 4 (Black/White wire). If resistance is greater than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, repair short to ground in Black/White wire.
- Measure voltage between ground and input side circuit breaker No. 7 in power distribution box. If battery voltage exists, repair open in Black/White wire. If battery voltage does not exist, repair open in power supply to power distribution box. See appropriate wiring diagram in POWER DISTRIBUTION article in WIRING DIAGRAMS.
- Measure voltage between ground and DDM harness connector C520 terminal No. 3 (Yellow/Light Green wire). If battery voltage does not exist, go to next step. If battery voltage exists, go to step 7 .
- Remove maxi-fuse No. 28 (20-amp) from central junction box. Measure resistance between ground and DDM harness connector C520 terminal No. 3 (Yellow/Light Green wire). If resistance is greater than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, repair short to ground in Yellow/Light Green wire.
- Measure voltage at input side maxi-fuse No. 28 in central junction box. If battery voltage exists, repair open in Yellow/Light Green wire. If battery voltage does not exist, repair open in power supply to central junction box. See appropriate wiring diagram in POWER DISTRIBUTION article in WIRING DIAGRAMS.
- Disconnect DDM harness connector C519. Measure resistance between ground and DDM harness connector C519 terminals No. 4 (Pink/Orange wire) and No. 15 (Black wire). See Fig 2 . If either resistance reading is greater than 5 ohms, repair open in appropriate wire. If both resistance readings are 5 ohms or less, repair module communications problem. See MODULE COMMUNICATIONS NETWORK - CROWN VICTORIA & GRAND MARQUIS article.