GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

Schematic Reference: Heated Seats Schematics

Connector End View Reference: Power Seat Connector End Views

1

Did you review the Heated Seat System Description and Operation and perform the necessary inspections?

--

Go to Step 2

Go to Symptoms - Seats

2

Verify that the Heated Seat Inoperative complaint is present.

Does the heated seat system operate as described in the system description and operation?

--

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

Go to Step 3

3

  1. Turn ON the ignition, with the engine OFF.
  2. While observing the heated seat switch temperature indicators, place the heated seat switch in the HIGH and LOW positions.

Do the HI and LO temperature indicators illuminate?

--

Go to Step 4

Go to Step 21

4

  1. Probe the heated seat element supply voltage circuit of the heated seat module with a test lamp that is connected to a good ground.
  2. Place the heated seat switch in the HIGH heat position.

Does the test lamp illuminate?

--

Go to Step 11

Go to Step 5

5

  1. Turn Off the ignition.
  2. Disconnect the heated seat module.
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a test lamp from the battery positive voltage circuit of the heated seat module connector to a good ground.

Does the test lamp illuminate?

--

Go to Step 6

Go to Step 27

6

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

Does the test lamp illuminate?

--

Go to Step 7

Go to Step 28

7

  1. Connect a test lamp from the heated seat switch signal circuit of the heated seat module connector to a good ground.
  2. Place the heated seat switch in the HIGH heat position.

Does the test lamp illuminate?

--

Go to Step 8

Go to Step 18

8

  1. Turn OFF the ignition.
  2. Place the heated seat switch in the HIGH heat position.
  3. Measure the resistance between the heated seat switch signal circuit of the heated seat module connector and the heated seat high/low signal circuit of the module connector.

Dose the resistance measure near the specified value?

310 ohms

Go to Step 9

Go to Step 15

9

  1. Place the heated seat switch in the LOW heat position.
  2. Measure the resistance between the heated seat switch signal circuit of the heated seat module connector and the heated seat high/low signal circuit of the module connector.

Dose the resistance measure near the specified value?

200 ohms

Go to Step 10

Go to Step 23

10

Important: If the resistance is measured with the seat still warm, the resistance may very outside of the specified range since the thermistor resistance varies with temperature.

Measure the resistance between the temperature sensor signal circuit of the heated seat module connector and the ground circuit of the module connector.

Does the resistance measure within the specified range?

7,000-11,000 ohms

Go to Step 13

Go to Step 16

11

  1. Disconnect the heated seat cushion heating element connector.
  2. Measure the resistance across the cushion heating element connector.

Does the resistance measure less than the specified value?

5 ohms

Go to Step 12

Go to Step 24

12

  1. Disconnect the heated seat back heating element connector.
  2. Measure the resistance across the back heating element connector.

Does the resistance measure less than the specified value?

5 ohms

Go to Step 19

Go to Step 25

13

Test the signal circuit of the heated seat temperature sensor for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 34

Go to Step 14

14

  1. Turn ON the ignition, with the engine OFF.
  2. Test the heated seat high/low signal circuit between the heated seat switch and the heated seat module for a short to battery voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 34

Go to Step 26

15

Test the heated seat high/low signal circuit between the heated seat switch and the heated seat module for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 34

Go to Step 23

16

Test the ground circuit of the heated seat temperature sensor for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 34

Go to Step 17

17

Test the signal circuit of the heated seat temperature sensor for a short to battery voltage or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 34

Go to Step 24

18

Test the heated seat switch signal circuit between the heated seat switch and the heated seat module for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 34

Go to Step 23

19

Test the heated seat element supply voltage circuit between the heated seat module and the seat cushion heating element for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 34

Go to Step 20

20

Test the heated seat element supply voltage circuit between the seat cushion the seat back heating elements for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 34

Go to Step 29

21

Test the battery positive voltage circuit of the heated seat switch for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 34

Go to Step 22

22

Test the ground circuit heated seat switch for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 34

Go to Step 23

23

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

Did you find and correct the condition?

--

Go to Step 34

Go to Step 30

24

Inspect for poor connections at the harness connector of the heated seat cushion heating element/temperature sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 34

Go to Step 31

25

Inspect for poor connections at the harness connector of the heated seat back heating element. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 34

Go to Step 32

26

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

Did you find and correct the condition?

--

Go to Step 34

Go to Step 33

27

Repair the open or short to ground in the battery positive voltage circuit of the heated seat module. Refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 34

--

28

Repair the open in the ground circuit of the heated seat module. Refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 34

--

29

Repair the open in the ground circuit of the seat heating elements. Refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 34

--

30

Replace the heated seat switch. Refer to Front Seat Heater Switch Replacement .

Is the repair complete?

--

Go to Step 34

--

31

Replace the seat cushion heater element/temperature sensor. Refer to Front Seat Heater Element Replacement .

Is the repair complete?

--

Go to Step 34

--

32

Replace the seat back heater element. Refer to Front Seat Heater Element Replacement .

Is the repair complete?

--

Go to Step 34

--

33

Replace the heated seat control module. Refer to Front Seat Heater Control Module Replacement .

Is the repair complete?

--

Go to Step 34

--

34

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2