FixVault

Test B: No Communication With Central Security Module

NOTE: Central locking module may also be referred to as Central Security Module (CSM).
  1. Turn ignition switch to OFF position. Disconnect central locking module harness connector C451A. Measure voltage between ground and central locking module harness connector C451A terminal No. 1 (Orange/White wire). See Figure . If battery voltage exists, go to next step. If battery voltage does not exist, repair power distribution circuit as necessary. Check for blown fuse No. 25 (20-amp) in Central Junction Box (CJB). If fuse is blown, repair short to ground in Orange/White wire between central locking module and CJB. If fuse is okay, repair open in Orange/White wire between central locking module and CJB. See appropriate wiring diagram in POWER DISTRIBUTION article in WIRING DIAGRAMS.
  2. Turn ignition switch to ON position. Measure voltage between ground and central locking module harness connector C451A terminal No. 10 (Orange/White wire). If battery voltage exists, go to next step. If battery voltage does not exist, repair power distribution circuit as necessary. Check for blown fuse No. 30 (7.5-amp) in CJB. If fuse is blown, repair short to ground in Green/White wire between central locking module and CJB. If fuse is okay, repair open in Green/White wire between central locking module and CJB. See appropriate wiring diagram in POWER DISTRIBUTION article in WIRING DIAGRAMS.
  3. Turn ignition switch to OFF position. Measure resistance between ground and Black wires at central locking module harness connector C451A terminal No. 5 and 11. If both resistance readings are 5 ohms or less, repair module communication concern. See MODULE COMMUNICATIONS NETWORK - COUGAR article. If either resistance reading is more than 5 ohms, repair open in appropriate Black wire between central locking module and ground point (bottom of passenger side "A" pillar).