Test Z: No Communication With RCM
WARNING: This page is about a different car, the 2002 Mazda B4000, 2002 Mazda B3000, and 2002 Mazda B2300. However, it is still accessible from the selected car via links, so may be relevant.
- Check RCM connector & pin for damage
Turn ignition switch to OFF position. Disable air bag system. See DISABLING SYSTEM under DISABLING & ACTIVATING AIR BAG SYSTEM. Access RCM and disconnect harness connector. See RESTRAINTS CONTROL MODULE (RCM) under REMOVAL & INSTALLATION. Inspect RCM connector, terminal No. 5 (Light Blue/White wire), component side and harness side, for damage. See Figure & Figure . If module pin and module harness connector terminal No. 5 are okay, go to next step. If module pin and module harness connector terminal No. 5 are damaged, repair/replace as necessary. Reconnect air bag system. Reactivate air bag system. See ACTIVATING SYSTEM under DISABLING & ACTIVATING AIR BAG SYSTEM. Prove out system. See PROVE OUT SYSTEM under DIAGNOSTICS. Clear all DTCs. See CLEARING FAULT CODES under DIAGNOSTICS. - Check DLC for damage
Inspect Data Link Connector (DLC) and DLC connector terminal No. 7 (Light Blue/White wire) for damage. See Fig 1 . DLC is located under left side of instrument panel. If DLC connector and DLC connector terminal No. 7 (Light Blue/White wire) is okay, go to next step. If DLC connector and DLC connector terminal No. 7 (Light Blue/White wire) is damaged, repair/replace as necessary. Retest communication with RCM. Reconnect air bag system. Reactivate air bag system. Prove out system. Clear all DTCs. - Check circuit for short to battery
Measure voltage between ground and DLC connector terminal No. 7 (Light Blue/White wire). If any voltage is present, repair short to battery voltage in Light Blue/White wire. Retest communication with RCM. Reconnect air bag system. Reactivate air bag system. Prove out system. Clear all DTCs. If no voltage is present, go to next step. - Check circuit for open
Measure resistance of Light Blue/White wire between RCM connector terminal No. 5 and DLC connector terminal No. 7. See Figure & Fig 1 . If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open in Light Blue/White wire. Retest communication with RCM. Reconnect air bag system. Reactivate air bag system. Prove out system. Clear all DTCs. - Check circuit for short to ground
Measure resistance between ground and DLC connector terminal No. 7 (Light Blue/White wire). If resistance is less than 10 k/ohms, repair short to ground in Light Blue/White wire. Retest communication with RCM. Reconnect air bag system. Reactivate air bag system. Prove out system. Clear all DTCs. If resistance is more than 10 k/ohms, replace RCM. Retest communication with RCM. Reconnect air bag system. Reactivate air bag system. Prove out system. Clear all DTCs.