Test D: Heated Seat Inoperative

Review heated seat system. See HEATED SEATS under DESCRIPTION & OPERATION. Perform necessary inspections. See PRELIMINARY INSPECTION under TROUBLE SHOOTING. After review, go to next step.
Turn ignition switch to RUN position. Turn heated seat switch to ON position. If heated seat does not operate properly, go to next step. If heated seat operates properly, fault may be intermittent. Check for intermittent or poor connections. See PRELIMINARY INSPECTION under TROUBLE SHOOTING.
If heated seat switch indicator does not illuminate when switch is turned to ON position, go to next step. If heated seat switch indicator illuminates when switch is turned to ON position, go to step 6.
Check for high resistance or open in Brown wire between DRL/HVAC TEMP/HTD ST fuse (10-amp) and heated seat switch harness connector terminal "C". See Fig 1. If Brown wire is okay, go to next step. If Brown wire is not okay, repair as necessary. After repair, go to step 17.

Fig 1: Identifying Heated Seat Switch Harness Connector Terminals
Courtesy of GENERAL MOTORS CORP.
Check for high resistance or open in Black wire (ground circuit) between ground and suspect heated seat harness connector (C313 on driver's side or C314 on passenger's side) terminal "A". See Figure. If Black wire is okay, go to step 11. If Black wire is not okay, repair as necessary. After repair, go to step 17.
Disconnect suspect heated seat 8-pin harness connector (C313 on driver's side or C314 on passenger's side). Connect a test light between ground and heated seat cushion harness connector terminal "B" (Light Blue wire on driver's side; Light Blue/Black wire on passenger's side). See Figure. Turn ignition switch to RUN position. Turn heated seat switch to ON position. If test light illuminates, go to next step. If test light does not illuminate, go to step 10.
Check for open or short to ground in Orange wire between PWR SEAT CIRCUIT BREAKER fuse (30-amp) and suspect seat cushion harness connector (C313 on driver's side or C314 on passenger's side) terminal "F". If Orange wire is okay, go to next step. If Orange wire is not okay, repair as necessary. After repair, go to step 17.
Check for high resistance or open in Black wire (ground circuit) between suspect heated seat cushion harness connector terminal "A". If Black wire is okay, go to next step. If Black wire is not okay, repair as necessary. After repair, go to step 17.
Disconnect heated seat back element connector. Measure resistance of heated seat back element. If resistance is not 0.5-2 ohms, go to step 13. If resistance is 0.5-2 ohms, go to step 15.
Check for high resistance in Light Blue wire on driver's side or Light Blue/Black wire on passenger's side between heated seat cushion harness connector terminal "B" and heated seat switch harness connector terminal "E". If Light Blue wire or Light Blue/Black wire are okay, go to next step. If Light Blue wire or Light Blue/Black wire are not okay, repair as necessary. After repair, go to step 17.
Check suspect heated seat switch connector for intermittent or poor terminal contact. If connector or terminal contact is okay, go to next step. If connector or terminal contact is not okay, repair as necessary. After repair, go to step 17.
Replace heated seat switch. After repair, go to step 17.
Check heated seat back element connector for intermittent and poor terminal contact. If terminal contact is okay, go to next step. If terminal contact is not okay, repair as necessary. After repair, go to step 17.
Replace heated seat back element. After repair, go to step 17.
Check appropriate heated seat cushion harness connector for intermittent and poor terminal contact. If terminal contact is okay, go to next step. If terminal contact is not okay, repair as necessary. After repair, go to step 17.
Replace heated seat cushion element. After repair, go to next step.
Operate system to verify fault no longer exists. If fault still exists, go to step 2.