Test I: Passive Anti-Theft System Transceiver Signal Is Not Received
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.
- Turn ignition switch to LOCK position. Connect New Generation Star (NGS) tester to Data Link Connector (DLC). DLC is located below driver's side of instrument panel, to right of steering column. Turn ignition switch to RUN position. Using NGS tester, perform instrument cluster self-test. If DTC B1681 is retrieved, go to next step. If DTC B1681 is not retrieved, system is okay at this time.
- Turn ignition switch to LOCK position. Disconnect White 4-pin transceiver module harness connector C221. Transceiver module is located on steering column, under steering column covers. Turn ignition switch to RUN position. Measure voltage between ground and transceiver module harness connector C221 terminal No. 2 (White/Light Blue wire). See Fig 1 . If more than 9 volts exist, go to next step. If 9 volts or less exist, repair open or short in White/Light Blue wire between transceiver module and fuse No. 34 (20-amp) located in Central Junction Box (CJB). CJB is located behind left side of instrument panel. See WIRING DIAGRAMS .
- Turn ignition switch to LOCK position. Measure resistance between ground and transceiver module harness connector C221 terminal No. 1 (Black/White wire). If resistance is 5 ohms or less, go to next step. If resistance is more than 5 ohms, repair open in Black/White wire between transceiver module and ground. Ground point is located behind center of instrument panel. See WIRING DIAGRAMS .
- Reconnect transceiver module harness connector C221. Turn ignition switch to RUN position. Measure voltage (backprobe) between ground and White 4-pin transceiver module harness connector C221 terminal No. 3 (Gray/Orange wire). If 9 volts or less exist, go to next step. If more than 9 volts exist, go to step 6 .
- Turn ignition switch to LOCK position. Disconnect transceiver module harness connector C221. Measure resistance between ground and transceiver module harness connector C221 terminal No. 3 (Gray/Orange wire). If resistance is more than 100 ohms, go to next step. If resistance is 100 ohms or less, check Gray/Orange wire for short to ground. Repair as necessary. If Gray/Orange wire is okay, replace instrument cluster. See ANALOG INSTRUMENT PANELS - MUSTANG article. Perform TEST J: SECURITY IDENTIFICATION DOES NOT MATCH BETWEEN INSTRUMENT CLUSTER & POWERTRAIN CONTROL MODULE .
- Turn ignition switch to LOCK position. Disconnect transceiver module harness connector C221 (if connected). Disconnect 12-pin instrument cluster harness connector C250. It may be necessary to remove instrument cluster for access to connector. See ANALOG INSTRUMENT PANELS - MUSTANG article. Measure resistance of Gray/Orange wire between instrument cluster harness connector C250 terminal No. 7 and transceiver module harness connector C221 terminal No. 3. See Fig 1 and Fig 2 . If resistance is 5 ohms or less, go to next step. If resistance is more than 5 ohms, repair open in Gray/Orange wire between instrument cluster and transceiver module. See WIRING DIAGRAMS .
- Ensure ignition switch is in LOCK position. Reconnect transceiver module harness connector C221. Connect instrument cluster harness connector C250. Turn ignition switch to RUN position. Measure voltage (backprobe) between ground and transceiver module harness connector C221 terminal No. 4 (White/Light Green wire). If 9 volts or less exist, go to next step. If more than 9 volts exist, go to step 9 .
- Turn ignition switch to LOCK position. Disconnect transceiver module harness connector C221. Measure resistance between ground and transceiver module harness connector C221 terminal No. 4 (White/Light Green wire). If resistance is more than 100 ohms, go to next step. If resistance is 100 ohms or less, check for short to ground in White/Light Green wire between transceiver module and instrument cluster. See WIRING DIAGRAMS . Repair as necessary. If White/Light Green wire is okay, replace instrument cluster. See ANALOG INSTRUMENT PANELS - MUSTANG article. Perform TEST J: SECURITY IDENTIFICATION DOES NOT MATCH BETWEEN INSTRUMENT CLUSTER & POWERTRAIN CONTROL MODULE .
- Connect transceiver module harness connector C221 (if disconnected). Turn ignition switch to RUN position. Using NGS tester, trigger instrument cluster active command RF SIGNAL to on. Measure voltage (backprobe) between ground and transceiver module harness connector C221 terminal No. 4 (White/Light Green wire) while triggering active command RF SIGNAL from on to off. More than 9 volts should exist in OFF position and less than one volt in ON position. If voltage is as specified, go to next step. If voltage is not as specified, check for open in White/Light Green wire between transceiver module and instrument cluster. Repair as necessary. If White/Light Green wire is okay, replace instrument cluster. See ANALOG INSTRUMENT PANELS - MUSTANG article. Perform TEST J: SECURITY IDENTIFICATION DOES NOT MATCH BETWEEN INSTRUMENT CLUSTER & POWERTRAIN CONTROL MODULE .
- Turn ignition switch to LOCK position. Replace transceiver module. See REMOVAL & INSTALLATION . Turn ignition switch to RUN position. Using NGS tester, perform instrument cluster self-test. If DTC B1681 is retrieved, go to next step. If DTC B1681 is not retrieved, system is okay at this time.
- Turn ignition switch to LOCK position. Replace instrument cluster. See ANALOG INSTRUMENT PANELS - MUSTANG article. After replacing instrument cluster, perform TEST J: SECURITY IDENTIFICATION DOES NOT MATCH BETWEEN INSTRUMENT CLUSTER & POWERTRAIN CONTROL MODULE . Turn ignition switch to RUN position. Using NGS tester, perform instrument cluster self-test. If any DTCs are retrieved, go to next step. If no DTCs are retrieved, system is okay at this time.
- If any DTCs other than B1681 are retrieved, perform appropriate test. See INSTRUMENT CLUSTER DIAGNOSTIC TROUBLE CODE INDEX table under SELF-DIAGNOSTIC SYSTEM. If DTC B1681 is retrieved, check White/Light Green wire and Gray/Orange wire between transceiver module and instrument cluster. Check Black/White wire between transceiver module and ground. Check White/Light Blue wire between transceiver module and fuse No. 34 (20-amp) located in Central Junction Box (CJB). CJB is located below left side of instrument panel. See WIRING DIAGRAMS . Repair as necessary.