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 are present, see MODULE COMMUNICATIONS NETWORK - WINDSTAR article. If no DTCs are present, go to next step.
- Remove fuse No. 14 (10-amp) from junction panel fuse block. Turn ignition on. Using voltmeter, measure voltage between ground and input terminal (left terminal) on fuse No. 14 socket. If voltage is greater than 10 volts, go to next step. If voltage is 10 volts or less, repair open power supply circuit to fuse No.14.
- Turn ignition off. Install fuse No. 14 in junction panel fuse block. Disconnect interior mirror harness connector. Turn ignition on. Measure voltage between ground and terminal No. 7 (Red/Yellow wire) on interior mirror harness connector. If voltage is greater than 10 volts, go to next step. If voltage is 10 volts or less, repair open Red/Yellow wire.
- Turn ignition off. Measure resistance between ground and terminal No. 6 (Black wire) on interior mirror harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or greater, repair open Black wire.
- Turn ignition on. Ensure engine is not running. Measure voltage between ground and terminal No. 5 (Black/Pink wire) on interior mirror harness connector. If voltage is greater than 10 volts, go to step 8 . If voltage is 10 volts or less, go to next step.
- Ensure shift selector is Park position. Turn ignition off. Disconnect REM 22-pin C341 connector. REM is located in jack storage area. See Fig 2 . Using ohmmeter, measure resistance of Black/Pink wire between terminal No. 5 on interior mirror harness connector and terminal No. 4 on REM 22-pin harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or greater, repair open Black/Pink wire.
- Measure resistance between ground and terminal No. 4 (Black/Pink wire) on REM 22-pin harness connector. If resistance is greater than 10,000 ohms, go to next step. If resistance is 10,000 ohms or less, repair Black/Pink wire for short to ground.
- Turn ignition on. Using voltmeter, measure voltage between ground and terminal No. 4 (Black/Pink wire) on REM 22-pin harness connector. If voltage is greater than 10 volts, repair Black/Pink wire for short to voltage. If voltage is 10 volts or less, replace interior mirror. See INTERIOR MIRROR ASSEMBLY under REMOVAL & INSTALLATION. Test system for correct operation. If auto dimming mirror continues not to function, replace REM. Download module configuration information into new REM. Test system for correct 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.