GM Service Manual Online
For 1990-2009 cars only

Step

Action

Values

Yes

No

Schematic Reference: Driver Seat Schematics or Passenger Seat Schematics

Connector End View Reference: Power Seat Connector End Views or Computer/Integrating Systems Connector End Views in Computer/Integrating Systems

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 in Vehicle DTC Information

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 7

3

Are both heated seats inoperative?

--

Go to Step 4

Go to Step 7

4

  1. Disconnect connector C311.
  2. Using a test lamp connected to ground, probe the heated seat relay switched voltage supply circuit.

Does the test lamp illuminate?

--

Go to Step 6

Go to Step 5

5

Test for a short to ground or an open in the heated seat relay switched voltage supply circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 29

Go to Step 28

6

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool navigate to the driver heated seat output control screen by making the following selections:
  4. • Body and Accessories
    • Seats
    • Special functions
    • Body control module (BCM)
    • Miscellaneous tests
  5. Select the driver heated seat relay.
  6. Command the relay On and Off.

Does the heated seat relay turn On and Off with each command?

--

Go to Step 20

Go to Step 21

7

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, navigate to the heated seat output control screen by making the following selection:
  4. • Body and Accessories
    • Seats
    • Special functions
    • BCM
    • Miscellaneous test
  5. Press the appropriate heated seat switch.

Does the heated seat relay parameter momentarily display On then Off?

--

Go to Step 16

Go to Step 8

8

Does the heated seat relay parameter display On?

--

Go to Step 9

Go to Step 20

9

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

Does the test lamp illuminate?

--

Go to Step 12

Go to Step 10

10

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 11

Go to Step 22

11

  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 17

Go to Step 21

12

  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 13

Go to Step 18

13

  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 14

Go to Step 19

14

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 Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 29

Go to Step 15

15

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 in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 29

Go to Step 23

16

Test the heated seat relay control 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 29

Go to Step 17

17

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 in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 29

Go to Step 24

18

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 29

Go to Step 25

19

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 in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 29

Go to Step 25

20

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 in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 29

Go to Step 26

21

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

Did you find and correct the condition?

--

Go to Step 29

Go to Step 27

22

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

Did you complete the repair?

--

Go to Step 29

--

23

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

Did you complete the repair?

--

Go to Step 29

--

24

Replace the heated seat relay. Refer to Front Seat Heater Relay Replacement .

Did you complete the replacement?

--

Go to Step 29

--

25

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

Did you complete the replacement?

--

Go to Step 29

--

26

Replace the HVAC control module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 29

--

27

Replace the BCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 29

--

28

Replace the instrument panel (I/P) fuse block. Refer to Instrument Panel Electrical Center or Junction Block Replacement .

Did you complete the repair?

--

Go to Step 29

--

29

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2