GM Service Manual Online
For 1990-2009 cars only

Step

Action

Values

Yes

No

Schematic Reference: Driver Seat Schematicsor Passenger Seat Schematics

Connector End View Reference: Power Seat Connector End Views

DEFINITION: This test assumes that Load Shed Level 1 or Level 2 Heated Seats is not enabled.

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

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

Go to Step 3

3

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the appropriate Heated Seat Relay parameter in the body control module (BCM) output data list.
  4. Press the appropriate heated seat switch.

Does the Heated Seat Relay parameter momentarily display On then Off?

--

Go to Step 12

Go to Step 4

4

Does the Heated Seat Relay parameter display On?

--

Go to Step 5

Go to Step 16

5

  1. Connect a test lamp from the heated seat element supply voltage circuit of the heated seat relay to a good ground.
  2. Press the heated seat switch.

Does the test lamp illuminate?

--

Go to Step 8

Go to Step 6

6

Connect a test lamp from the battery positive voltage circuit of the heated seat relay to ground.

Does the test lamp illuminate?

--

Go to Step 7

Go to Step 18

7

  1. Connect a test lamp from the heated seat relay control circuit of the heated seat relay to ground.
  2. Press the heated seat switch.

Does the test lamp illuminate?

--

Go to Step 13

Go to Step 17

8

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

Does the resistance measure less than the specified value?

5 ohms

Go to Step 9

Go to Step 14

9

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

Does the resistance measure less than the specified value?

5 ohms

Go to Step 10

Go to Step 15

10

Test the heated seat element supply voltage circuit between the heated seat relay and the seat cushion heating element for an open. Refer to Circuit Testingand Wiring Repairs.

Did you find and correct the condition?

--

Go to Step 24

Go to Step 11

11

Test the heated seat element supply voltage circuit between the seat cushion and the seat back heating element for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 24

Go to Step 19

12

Test the heated seat relay control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs.

Did you find and correct the condition?

--

Go to Step 24

Go to Step 13

13

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

Did you find and correct the condition?

--

Go to Step 24

Go to Step 20

14

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.

Did you find and correct the condition?

--

Go to Step 24

Go to Step 21

15

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

Did you find and correct the condition?

--

Go to Step 24

Go to Step 21

16

Inspect for poor connections at the harness connector of the HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 24

Go to Step 22

17

Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs.

Did you find and correct the condition?

--

Go to Step 24

Go to Step 23

18

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

Did you complete the repair?

--

Go to Step 24

--

19

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

Did you complete the repair?

--

Go to Step 24

--

20

Replace the heated seat relay. Refer to Relay Replacement.

Did you complete the replacement?

--

Go to Step 24

--

21

Replace the appropriate seat cushion heating element/temperature sensor or seat back heating element. Refer to Driver or Passenger Seat Back Cushion Heater Replacement and to Driver or Passenger Seat Cushion Heater Replacement.

Did you complete the replacement?

--

Go to Step 24

--

22

Replace the HVAC control module. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 24

--

23

Replace the BCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 24

--

24

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2