Heated Element: Testing and Inspection

For circuit descriptions and diagrams, (Refer to Appropriate Wiring Information).
1. If both mirror heaters are inoperative, check for proper operation of the Rear Window Defogger System. (Refer to ELECTRICAL/HEATED GLASS - DIAGNOSIS AND TESTING - REAR WINDOW DEFOGGER SYSTEM). If Rear Window Defogger System operates correctly or if only one mirror heater is inoperative, go to Step 2.
2. Disconnect and isolate the battery negative cable. Remove the front door trim panel on the side of the inoperative mirror heater. Go to Step 3.
3. Disconnect the door wire harness connector from the door module connector receptacle. Check for continuity between the mirror heater 12 volt supply and the mirror heater ground. There should be continuity. If OK, go to Step 4. If not OK, check for continuity of the individual circuits between the power mirror and the door module, and of the mirror heater grid right at the power mirror.
4. Use a DRB III and (Refer to Appropriate Diagnostic Information) to test the door module and the PCI data bus.