GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Driver Seat Schematics or Passenger Seat Schematics

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

Operate the heated seats.

Does the system operate normally?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

Is the inoperative heated seat on the passengers side?

Go to Step 4

Go to Step 6

4

  1. Disconnect the passengers side heated seat switch.
  2. Insert the seat belt buckle into the seat belt latch.
  3. Connect a test lamp between battery positive voltage and the seat belt switch signal circuit at the heated seat switch connector.

Did the test lamp illuminate?

Go to Step 5

Go to Step 6

5

  1. Disconnect the passengers side seat belt switch connector under the seat cushion.
  2. Insert the seat belt buckle into the seat belt latch.
  3. Test for continuity across the seat belt switch connector.

Is continuity present across the seat belt switch connector with the seat belt buckle inserted into the seat belt latch?

Go to Step 19

Go to Step 18

6

  1. Disconnect the inoperative heated seat switch.
  2. Turn ON the ignition, with the engine OFF.
  3. Connect a test lamp between the ignition 3 voltage circuit at the inoperative heated seat switch connector and a good ground.

Did the test lamp illuminate?

Go to Step 7

Go to Step 14

7

Connect a test lamp between the ground circuit at the heated seat switch connector and battery positive voltage.

Did the test lamp illuminate?

Go to Step 8

Go to Step 15

8

  1. Reconnect the heated seat switch.
  2. Disconnect the inoperative seat heater module.
  3. Connect a test lamp between the heated seat hi/low signal circuit and a good ground.
  4. Turn ON the ignition, with the engine OFF.
  5. Operate the heated seat switch to the HI and LOW positions.

Did the test lamp illuminate?

Go to Step 9

Go to Step 11

9

Connect a test lamp between the battery positive voltage circuit at the seat heater module connector and a good ground.

Did the test lamp illuminate?

Go to Step 10

Go to Step 16

10

Connect a test lamp between the ground circuit at the heated seat element connector and battery positive voltage.

Did the test lamp illuminate?

Go to Step 13

Go to Step 17

11

Test the heated seat switch signal circuit for a open, high resistance or a short to ground.

Did you find and correct the condition?

Go to Step 22

Go to Step 12

12

Inspect for poor connections at the harness connector of the inoperative heated seat switch. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Did you find and correct the condition?

Go to Step 22

Go to Step 21

13

Inspect for poor connections at the harness connector of the inoperative seat heater module. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Did you find and correct the condition?

Go to Step 22

Go to Step 20

14

Repair the open or short to ground in the ignition 3 voltage circuit to the inoperative heated seat switch. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 22

--

15

Repair the open in the ground circuit at the inoperative heated seat switch. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 22

--

16

Repair the open or short to ground in the battery positive voltage circuit at the inoperative seat heater module. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 22

--

17

Repair the open in the ground circuit at the inoperative seat heater module. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 22

--

18

Repair the short to ground in the seat belt switch signal circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 22

--

19

Replace the seat belt switch.

Did you complete the replacement?

Go to Step 22

--

20

Replace the inoperative seat heater module.

Did you complete the replacement?

Go to Step 22

--

21

Replace the inoperative heated seat switch.

Did you complete the replacement?

Go to Step 22

--

22

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2