GM Service Manual Online
For 1990-2009 cars only

Step

Action

Values

Yes

No

Schematic Reference: Heated Seats Schematics

1

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

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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 rear heated seat 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 13

4

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

Does the test lamp illuminate?

--

Go to Step 5

Go to Step 14

5

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

Does the test lamp illuminate?

--

Go to Step 6

Go to Step 15

6

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

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

--

Go to Step 7

Go to Step 16

7

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

Does the rear heated seat high indicator illuminate?

--

Go to Step 8

Go to Step 18

8

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

Does the rear heated seat low indicator illuminate?

--

Go to Step 9

Go to Step 19

9

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

Is the resistance within the specified values?

7K-12K ohms

Go to Step 10

Go to Step 11

10

Test the resistance through the seat cushion heater element from the element supply circuit terminal to the ground circuit terminal in the rear heated seat module harness connector. Refer to Circuit Testing in Wiring Systems.

Is the resistance within the specified values?

0.5-2.0 ohms

Go to Step 22

Go to Step 12

11

Test the thermistor reference and signal circuits for an open, short to ground, or short to voltage. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 23

Go to Step 21

12

Test the seat cushion heater element supply and ground circuits 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 23

Go to Step 21

13

Repair the ignition voltage supply circuit to the rear heated seat 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 23

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14

Repair the battery voltage supply circuit to the rear heated seat 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 23

--

15

Repair the rear heated seat 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 23

--

16

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

Did you find and correct the condition?

--

Go to Step 23

Go to Step 17

17

Test the rear 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 23

Go to Step 20

18

  1. Disconnect the rear heated seat switch connector.
  2. Test the rear heated seat high indicator control 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 23

Go to Step 20

19

  1. Disconnect the rear heated seat switch connector.
  2. Test the rear heated seat low indicator control 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 23

Go to Step 20

20

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

Is the repair complete?

--

Go to Step 23

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21

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

Is the repair complete?

--

Go to Step 23

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22

Replace the rear heated seat module.

Is the repair complete?

--

Go to Step 23

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23

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2