GM Service Manual Online
For 1990-2009 cars only

Step

Action

Values

Yes

No

Schematic Reference: Heated Seats Schematics

DEFINITION: One or both of the front heated seats are inoperative.

1

Has the Heated Seats System Check been performed?

--

Go to Step 2

Go to Heated Seats System Check

2

Is the front passenger seat heater inoperative in the high and low modes?

--

Go to Step 3

Go to Step 4

3

  1. Disconnect the passenger seat belt buckle switch connector C228.
  2. Turn ON the ignition.
  3. Operate the front passenger heated seat switch in the high and low modes.

Does the front passenger heated seat operate in the high and low modes?

--

Go to Step 25

Go to Step 4

4

  1. Disconnect the heated seat module.
  2. Connect a test lamp from the harness connector terminal D to a good ground.

Does the test lamp illuminate?

--

Go to Step 5

Go to Step 17

5

Connect a test lamp from the heated seat module harness connector terminal D to terminal F.

Does the test lamp illuminate?

--

Go to Step 6

Go to Step 18

6

  1. Connect a test lamp from the heated seat module harness connector terminal C to ground.
  2. Turn ON the ignition.
  3. Operate the heated seat switch in the high and low switch positions.

Does the test lamp illuminate in the high and low switch positions?

--

Go to Step 7

Go to Step 10

7

  1. Turn OFF the ignition.
  2. Using a DMM measure the resistance through the heated seat switch from the heated seat module harness connector terminals C to B.
  3. Operate the heated seat switch in the high and low switch positions.

Is the resistance at or near the specified values?

    • High 496 ohms
    • Low 275 ohms

Go to Step 8

Go to Step 20

8

Using a DMM measure the resistance through the heated seat elements from the heated seat module harness connector terminals A to F.

Is the resistance within the specified values?

1-5 ohms

Go to Step 9

Go to Step 11

9

Using a DMM measure the resistance through the heated seat cushion temperature sensor from the heated seat module harness connector terminals E to F.

Is the resistance within the specified values?

5 k-15 k ohms

Go to Step 26

Go to Step 15

10

  1. Disconnect the heated seat switch connector.
  2. Connect a test lamp from the harness connector terminal D to ground.
  3. Turn ON the ignition.

Does the test lamp illuminate?

--

Go to Step 19

Go to Step 21

11

  1. Connect the heated seat module connector.
  2. Turn ON the ignition.
  3. Operate the heated seat switch to the high position.
  4. Using a test lamp connected to ground back probe the seat cushion element 4-way connector terminal A.

Does the test lamp illuminate?

--

Go to Step 12

Go to Step 22

12

With the ignition ON and the heated seat switch in the high mode, back probe the seat cushion element 4-way connector terminal B with a test lamp connected to ground.

Does the test lamp illuminate?

--

Go to Step 13

Go to Step 27

13

With the ignition ON and the heated seat switch in the high mode, back probe the seat back element 2-way connector terminal A with a test lamp connected to ground.

Does the test lamp illuminate?

--

Go to Step 14

Go to Step 23

14

With the ignition ON and the heated seat switch in the high mode, back probe the seat back element 2-way connector terminal B with a test lamp connected to ground.

Does the test lamp illuminate?

--

Go to Step 24

Go to Step 28

15

  1. Disconnect the seat cushion element 4-way connector.
  2. Test circuit 182 for an open or short to ground. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Heated Seats System Check

Go to Step 16

16

Test circuit 150 from the seat cushion element 4-way connector to the heated seat module connector for an open. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Heated Seats System Check

Go to Step 27

17

Repair circuit 1840 for an open or short to ground. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Heated Seats System Check

--

18

Repair circuit 150 for an open or high resistance. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Heated Seats System Check

--

19

Test circuit 1503 for an open or short to ground. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Heated Seats System Check

Go to Step 29

20

Test circuit 1505 for an open or short to ground. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Heated Seats System Check

Go to Step 29

21

Repair circuit 341 for an open or short to ground. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Heated Seats System Check

--

22

Repair circuit 1462 for an open or short to ground. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Heated Seats System Check

--

23

Repair circuit 1985 for an open or short to ground. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Heated Seats System Check

--

24

Repair circuit 150 from the seat back element 2-way connector to the heated seat module connector for an open or high resistance. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Heated Seats System Check

--

25

Replace the front passenger seat belt switch. Refer to Front Seat Belt Replacement .

Is the repair complete?

--

Go to Heated Seats System Check

--

26

Replace the heated seat module. Refer to Heater Module Replacement .

Is the repair complete?

--

Go to Heated Seats System Check

--

27

Replace the seat cushion heater element. Refer to Driver or Passenger Seat Cushion Heater Replacement .

Is the repair complete?

--

Go to Heated Seats System Check

--

28

Replace the seat back heater element. Refer to Driver or Passenger Seat Back Cushion Heater Replacement

Is the repair complete?

--

Go to Heated Seats System Check

--

29

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

Is the repair complete?

--

Go to Heated Seats System Check

--