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 or Body Control System Connector End Views

DEFINITION: This test assumes that load shed level 1 or 2 heated seats is not enabled.

1

Did you review the heated seat 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. Disconnect the heated seat module connector C1.
  2. Measure the voltage from the battery positive voltage circuit of the heated seat module to ground.

Does the voltage measure within the specified range?

9-15 V

Go to Step 4

Go to Step 28

4

Measure the voltage from the battery positive voltage circuit of the heated seat module to the ground circuit of the heated seat module.

Does the voltage measure within the specified range?

9-15 V

Go to Step 5

Go to Step 31

5

  1. Turn ON the ignition, with the engine OFF.
  2. Measure the voltage from the ignition 3 voltage circuit of the heated seat module to ground.

Does the voltage measure within the specified range?

9-15 V

Go to Step 6

Go to Step 29

6

Probe the heated seat high/low signal circuit of the heated seat module with a test lamp that is connected to ground.

Does the test lamp illuminate?

--

Go to Step 32

Go to Step 7

7

Probe the heated seat high/low signal circuit of the heated seat module with a test lamp that is connected to battery positive voltage.

Does the test lamp illuminate?

--

Go to Step 22

Go to Step 8

8

With the test lamp still connected from battery positive voltage to the high/low signal circuit of the heated seat module, activate the heated seat HI/LO switch.

Does the test lamp illuminate?

--

Go to Step 10

Go to Step 9

9

  1. Probe the heated seat high/low terminal of the heated seat switch with a test lamp that is connected to battery positive voltage.
  2. Activate the heated seat HI/LO switch.

Does the test lamp illuminate?

--

Go to Step 30

Go to Step 21

10

Probe the heated seat off signal circuit of the heated seat module with a test lamp that is connected to battery positive voltage.

Does the test lamp illuminate?

--

Go to Step 17

Go to Step 11

11

Probe the heated seat control module inhibit signal circuit of the heated seat module with a test lamp that is connected to battery positive voltage.

Does the test lamp illuminate?

--

Go to Step 18

Go to Step 12

12

  1. Disconnect the heated seat module connector C2.
  2. Measure the resistance between the heated seat element supply voltage circuit and the heated seat element control circuit of the module connector.

Does the resistance measure less than the specified value?

5 ohms

Go to Step 14

Go to Step 13

13

  1. Disconnect the seat back heating element connector.
  2. Measure the resistance between the heated seat element supply voltage circuit and the heated seat element control circuit of the seat back heating element connector.

Does the resistance measure less than the specified value?

5 ohms

Go to Step 23

Go to Step 24

14

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

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

Does the resistance measure within the specified range?

850 ohms-11,500 ohms

Go to Step 15

Go to Step 23

15

Test the temperature sensor signal circuit 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 38

Go to Step 16

16

Test the heated seat element control circuit of the seat heating elements 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 38

Go to Step 25

17

Test the heated seat off signal circuit between the heated seat module and the heated seat switch 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 38

Go to Step 27

18

  1. Disconnect the RIM connector C2.
  2. Using a test lamp connected to battery positive voltage, prove the heated seat control module inhibit signal at the heated seat module connector C1.

Does the test lamp illuminate?

--

Go to Step 20

Go to Step 19

19

  1. Connect the RIM connector C2.
  2. Disconnect the heated seat module connector C2.
  3. Using a test lamp connected to battery positive voltage, probe the heated seat control module inhibit signal circuit at the heated seat module connector C1.

Does the test lamp illuminate?

--

Go to Step 26

Go to Step 12

20

Repair the short to ground in the heated seat control module inhibit signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 38

--

21

Test the ground 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 38

Go to Step 27

22

Test the heated seat high/low signal circuit between the heated seat module and the heated seat switch 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 38

Go to Step 27

23

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 38

Go to Step 33

24

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 38

Go to Step 34

25

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 38

Go to Step 35

26

Inspect for poor connections at the harness connector of the rear integration 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 38

Go to Step 36

27

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 38

Go to Step 37

28

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

Did you complete the repair?

--

Go to Step 38

--

29

Repair the open in the ignition 3 voltage circuit of the heated seat module. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 38

--

30

Repair the open in the heated seat high/low signal circuit of the heated seat module. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 38

--

31

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

Did you complete the repair?

--

Go to Step 38

--

32

Repair the short to voltage in the heated seat high/low signal circuit of the heated seat module. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 38

--

33

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

Did you complete the replacement?

--

Go to Step 38

--

34

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

Did you complete the replacement?

--

Go to Step 38

--

35

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

Did you complete the replacement?

--

Go to Step 38

--

36

Replace the rear integration module. Refer to Rear Integration Body Control Module Replacement in Body Control Systems.

Did you complete the replacement?

--

Go to Step 38

--

37

Replace the heated seat switch. Refer to Heated Seat Switch Replacement .

Did you complete the replacement?

--

Go to Step 38

--

38

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2