Test F: Auto Dimming Mirror Does Not Operate Correctly
- Using New Generation Star (NGS) tester, perform Rear Electronic Module (REM) self-test. If any DTCs exist, see MODULE COMMUNICATIONS NETWORK - WINDSTAR article for DTC index. If no DTCs are present, go to next step.
- Remove fuse No. 14 (10-amp) from Central Junction Box (CJB). Turn ignition switch to RUN position. Measure voltage between ground and input terminal (left terminal) on fuse No. 14 socket. If more than 10 volts exists, go to next step. If 10 volts or less exists, repair open power supply circuit to fuse No. 14. See WIRING DIAGRAMS .
- Turn ignition off. Install fuse No. 14 in CJB. Disconnect interior mirror 7-pin harness connector C907. Turn ignition switch to RUN position. Measure voltage between ground and interior mirror connector C907 terminal No. 7 (Red/Yellow wire). If more than 10 volts exists, go to next step. If 10 volts or less exists, repair open in Red/Yellow wire between CJB and interior mirror connector. See WIRING DIAGRAMS . Recheck system operation.
- Turn ignition off. Measure resistance between ground and interior mirror connector C907 terminal No. 6 (Black wire). If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or greater, repair open in Black wire. See WIRING DIAGRAMS . Recheck system operation.
- Turn ignition switch to RUN position. Ensure engine is not running. Ensure parking brake is applied. Move gearshift selector to Reverse position. Measure voltage between ground and interior mirror connector C907 terminal No. 5 (Black/Pink wire). If more than 10 volts exists, go to step 8 . If 10 volts or less exists, go to next step.
- Shift selector to Park position. Turn ignition off. Disconnect Rear Electronics Module (REM) 22-pin connector C341. REM is located in jack storage area. See Fig 2 . Measure resistance in Black/Pink wire between interior mirror connector C907 terminal No. 5 and REM connector C341 terminal No. 4. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or greater, repair open in Black/Pink wire. See WIRING DIAGRAMS . Recheck system operation.
- Measure resistance between ground and REM connector C341 terminal No. 4 (Black/Pink wire). If resistance is greater than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, repair short to ground in Black/Pink wire between REM and interior rear view mirror. See WIRING DIAGRAMS . Recheck system operation.
- Turn ignition switch to RUN position. Measure voltage between ground and REM connector C341 terminal No. 4 (Black/Pink wire). If more than 10 volts exists, repair short to power in Black/Pink wire. See WIRING DIAGRAMS . Recheck system operation. If 10 volts or less exists, replace interior mirror. See INTERIOR MIRROR ASSEMBLY under REMOVAL & INSTALLATION. Recheck system operation. If auto dimming mirror continues not to function, replace REM. Download module configuration information into new REM. Recheck system operation.
NOTE:
Prior to replacement of REM module, it is necessary to upload module configuration information using NGS tester. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION.