Test E: Scan Tool Does Not Communicate With Sensing & Diagnostic Module
WARNING:
Vehicles are equipped with air bag supplemental restraint system. Before attempting any repairs involving steering column, instrument panel or related components, see SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM in appropriate AIR BAG RESTRAINT SYSTEMS article.
- If air bag diagnostic system check has been performed, go to next step. If air bag diagnostic system check has not been performed, perform air bag diagnostic system check. See AIR BAG SYSTEM DIAGNOSTIC SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM.
- Turn ignition switch to LOCK position. Remove and inspect air bag fuse (15-amp). Air bag fuse is a in-line fuse, attached to a carrier. If fuse is blown, replace air bag fuse and go to next step. If air bag fuse is not blown, go to step 8 .
- Disconnect Sensing and Diagnostic Module (SDM) harness connector. SDM is located under passenger seat. Using DVOM, measure resistance in Black wire between ground and SDM harness connector terminal A18. See Fig 1 . If resistance is less than 2 ohms, go to next step. If resistance is more than 2 ohms, go to step 11 .
- Turn ignition switch to RUN position. Using DVOM, measure voltage between ground and SDM harness connector terminal A1 (Blue/Red wire). If battery voltage exists, go to next step. If battery voltage does not exist, go to step 12 .
- Turn ignition switch to LOCK position. Measure resistance in Purple/Green wire between DLC terminal No. 7 and SDM harness connector terminal A4. See Figure and Fig 1 . If resistance is less than 2 ohms, go to next step. If resistance is more than 2 ohms, go to step 13 .
- Check continuity between ground and SDM terminal A4 (White/Black wire). If continuity does not exist, go to next step. If continuity does exist, go to step 14 .
- Turn ignition switch to RUN position. Measure voltage between ground and DLC terminal No. 7 (Purple/Green wire). If more than one volt exists, go to step 15 . If less than one volt exists, 16 .
- Disconnect Sensing and Diagnostic Module (SDM) harness connector. SDM is located under passenger seat. Check continuity between ground and SDM harness connector terminal A1 (Blue/Red wire). See Fig 1 . If continuity does not exist, go to next step. If continuity exists, go to step 10 .
- Reconnect SDM harness connector and perform air bag system diagnostic system check. See AIR BAG SYSTEM DIAGNOSTIC SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM.
- Repair short to ground in ignition voltage feed circuit between SDM and ignition switch. Replace air bag fuse (15-amp).
- Repair open in Black wire between SDM and ground. After repairs perform air bag system diagnostic system check. See AIR BAG SYSTEM DIAGNOSTIC SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM.
- Repair open in Black/White wire between SDM and ignition switch. After repairs perform air bag system diagnostic system check. See AIR BAG SYSTEM DIAGNOSTIC SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM.
- Repair open in Purple/Green wire or White/Black wire between SDM and DLC. After repairs perform air bag system diagnostic system check. See AIR BAG SYSTEM DIAGNOSTIC SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM.
- Repair short to ground in Purple/Green wire or White/Black wire between SDM and DLC. After repairs perform air bag system diagnostic system check. See AIR BAG SYSTEM DIAGNOSTIC SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM.
- Repair short to voltage in Purple/Green wire or White/Black wire between SDM and DLC. After repairs perform air bag system diagnostic system check. See AIR BAG SYSTEM DIAGNOSTIC SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM.
- Replace SDM. See REMOVAL & INSTALLATION in AIR BAG RESTRAINT SYSTEMS article. After repairs perform air bag system diagnostic system check. See AIR BAG SYSTEM DIAGNOSTIC SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM.
NOTE:
Wire color changes from White/Black wire at SDM terminal A4 to Purple/Green wire at DLC terminal No. 7 at in-line harness connector C215. In-line harness connector C215 is located at rear center of instrument panel.