GM Service Manual Online
For 1990-2009 cars only

Step

Action

Values

Yes

No

Schematic Reference: Heated Seats Schematics

Connector End View Reference: Power Seat Connector End Views

1

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

--

Go to Step 2

Go to Symptoms - Seats

2

Operate the rear heated seat system.

Does the system operate normally?

--

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

Go to Step 3

3

  1. Disconnect the heated seat control module connector.
  2. Connect a test lamp from the ignition voltage supply circuit terminal in the harness connector to ground.
  3. Turn the ignition on.

Does the test lamp illuminate?

--

Go to Step 4

Go to Step 11

4

Connect a test lamp test from the battery voltage supply circuit terminal in the heated seat control module harness connector to ground.

Does the test lamp illuminate?

--

Go to Step 5

Go to Step 12

5

Connect a test lamp from battery voltage to the ground circuit terminal in the heated seat control module harness connector.

Does the test lamp illuminate?

--

Go to Step 6

Go to Step 13

6

  1. Connect a test lamp from battery voltage to the heated seat switch signal circuit terminal in the heated seat control module harness connector.
  2. Press and release the heated seat switch.

Does the test lamp illuminate only while the heated seat switch is pressed?

--

Go to Step 7

Go to Step 14

7

Connect a fused jumper wire from battery voltage to the high indicator control circuit terminal in the heated seat control module harness connector.

Does the heated seat switch high indicator illuminate?

--

Go to Step 8

Go to Step 16

8

Connect a fused jumper wire from battery voltage to the low indicator control circuit terminal in the heated seat control module harness connector.

Does the heated seat switch low indicator illuminate?

--

Go to Step 9

Go to Step 17

9

Test the resistance through the heated seat thermistor from the heated seat control module harness connector. Refer to Circuit Testing in Wiring Systems.

Is the resistance within the specified values?

7K-12K ohms

Go to Step 10

Go to Step 18

10

Test the resistance through the seat cushion heater element from the heated seat control module harness connector.

Is the resistance less than the specified value?

5 ohms

Go to Step 23

Go to Step 18

11

Repair the ignition voltage supply circuit to the heated seat control module for an open or short to ground. Refer to Wiring Repairs and to Connector Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 25

--

12

Repair the battery voltage supply circuit to the heated seat control module for an open or short to ground. Refer to Wiring Repairs and to Connector Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 25

--

13

Repair the heated seat control module ground circuit for an open or high resistance. Refer to Wiring Repairs and to Connector Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 25

--

14

  1. Disconnect the heated seat switch connector.
  2. Test the heated seat switch signal circuit for an open or short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 25

Go to Step 15

15

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

Did you find and correct the condition?

--

Go to Step 25

Go to Step 19

16

  1. Disconnect the heated seat switch connector.
  2. Test the heated seat switch high indicator control circuit for an open or short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 25

Go to Step 19

17

  1. Disconnect the heated seat switch connector.
  2. Test the heated seat switch low indicator control circuit for an open or short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 25

Go to Step 19

18

  1. Disconnect the seat cushion heater element connector.
  2. Test the seat cushion heater element and thermistor circuits from the heated seat control module connector to the seat cushion heater element connector for an open or short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 25

Go to Step 21

19

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

Did you find and correct the condition?

--

Go to Step 25

Go to Step 20

20

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

Is the repair complete?

--

Go to Step 25

--

21

Inspect for poor connections at the seat cushion heater element connector. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 25

Go to Step 22

22

Replace the seat cushion heater element. Refer to Rear Seat Cushion Heater Replacement .

Is the repair complete?

--

Go to Step 25

--

23

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

Did you find and correct the condition?

--

Go to Step 25

Go to Step 24

24

Replace the heated seat control module.

Is the repair complete?

--

Go to Step 25

--

25

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3