GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Turn the ignition ON with the engine off.
  2. Operate the heated seat switch to the LOW or HI position.

Does the heated seat function properly?

--

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

Go to Step 2

2

Connect a test lamp between the heated seat relay module positive voltage circuit and a good ground.

Does the test lamp illuminate?

--

Go to Step 3

Go to Step 9

3

  1. Connect a test lamp to the heated seat element circuit and a good ground.
  2. Place the heated seat switch in the HI position.

Does the test lamp illuminate?

--

Go to Step 10

Go to Step 4

4

  1. Disconnect the seat cushion element circuit.
  2. Test for open in the heated seat element circuit.

Did you find and correct the condition?

--

Go to Step 5

Go to Step 17

5

  1. Disconnect the heated seat relay module.
  2. With the heated seat switch in the HI position.
  3. Use a test lamp connected to a good ground.
  4. Probe the Low/HI input circuit of the heated seat relay module.

Does the test lamp illuminate?

--

Go to Step 6

Go to Step 11

6

  1. With the heated seat switch in the HI position.
  2. Use a test lamp connected to a good ground.
  3. Probe the ON input circuit of the heated seat relay module.

Does the test lamp illuminate?

--

Go to Step 7

Go to Step 12

7

Using a test lamp connected to B+, probe the heated seat relay module ground circuit.

Does the test lamp illuminate?

--

Go to Step 8

Go to Step 13

8

Using a DMM, measure the resistance of the thermistor circuit at room temperature.

Is the resistance within the specified range?

8kohms - 12kohms

Go to Step 14

Go to Step 15

9

Repair a open or short to ground on the heated seat positive voltage circuit.

Did you complete the repair?

--

Go to Step 18

--

10

Repair the open on the heated seat element circuit.

Did you complete the repair?

--

Go to Step 18

Go to Step 16

11

Repair a short to ground or an open in the Low/HI input circuit.

Did you complete the repair?

--

Go to Step 18

--

12

Repair a open in the ON input circuit.

Did you complete the repair?

--

Go to Step 18

--

13

Repair a open in the ground circuit.

Did you complete the repair?

--

Go to Step 18

--

14

Repair a open in the heated seat element circuit.

Did you complete the repair?

--

Go to Step 18

Go to Step 16

15

Replace the heated seat switch.

Did you complete the repair?

--

Go to Step 18

--

16

Replace the heated seat.

Did you complete the repair?

--

Go to Step 18

--

17

Replace the heated seat relay module.

Did you complete the repair?

--

Go to Step 18

--

18

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 1