Test B: Air Bag Control Module Does Not Respond To Scan Tool
NOTE:
Depending on module configuration, with all modules connected and with ignition switch in RUN position or with engine running, 2-3 volts may be present at DLC terminal No. 7 (White wire with ABS; White/Red wire without ABS). This is the International Standards Organization (ISO) 9141 diagnostic communications network circuit.
- Turn ignition switch to LOCK position. Disarm air bag system. See appropriate AIR BAG RESTRAINT SYSTEMS article. Disconnect air bag control module connector C20. Inspect connector for loose, damaged or corroded terminals. If connector is okay, go to next step. If connector is damaged, repair connector as necessary. Check system for normal operation.
- Measure resistance between terminal No. 7 (White wire with ABS; White/Red wire without ABS) at DLC and terminal No. 5 (White/Red wire) at air bag control module connector. See Figure and Fig 1 . If resistance is less than 5 ohms, replace air bag control module (if equipped with ABS), or go to next step (if not equipped with ABS). If resistance is not less than 5 ohms, repair open in White/Red wire. Check system for normal operation.
- Turn ignition on. Measure voltage between ground and terminal No. 7 (White/Red wire) at DLC. If measurement indicates voltage, repair short to voltage in White/Red wire. Check system for normal operation. If measurement does not indicate voltage, go to next step.
- Measure resistance between ground and terminal No. 7 (White/Red wire) at DLC. If resistance is greater than 10 k/ohms, replace air bag control module. If resistance is not greater than 10 k/ohms, repair short to ground in White/Red wire. Check system for normal operation.