GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Is the right heated seat inoperative?

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Go to Step 2

Go to Step 8

2

  1. Remove the right heated seat switch.
  2. Backprobe CKT 541 (BRN) cavity C using a J 39200 digital multi-meter (DMM) and measure the voltage reading.
  3. Turn the ignition to run.

Does the J 39200 DMM read within the specified range?

11-14V

Go to Step 3

Go to Step 14

3

  1. Place the heated switch in the on position.
  2. Using a J 39200 DMM measure the voltage reading on CKT 1505 (LT BLU/BLK) cavity B.

Does the J 39200 DMM read within the specified range?

11-14V

Go to Step 4

Go to Step 15

4

  1. Locate the inline connector C399.
  2. Ensure the right seat switch is in the on position.
  3. Using a J 39200 DMM measure the voltage reading on CKT 1505 (LT BLU/BLK) cavity D.

Does the J 39200 DMM read within the specified range?

11-14V

Go to Step 5

Go to Step 16

5

Using a J 39200 DMM measure the voltage reading on CKT 2340 (ORN) cavity E of connector C399.

Does the J 39200 DMM read within the specified range?

11-14V

Go to Step 6

Go to Step 18

6

Using a J 39200 DMM measure the continuity on CKT 2350 (BLK) from C399 and ground.

Is continuity present on CKT 2350?

--

Go to Step 7

Go to Step 17

7

Replace the inoperative heated seat element and the electronic heated seat relay and wiring harness.

Is the repair complete?

--

Go to Heated Seats System Check

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8

  1. Remove the left heated seat switch.
  2. Backprobe CKT 541 (BRN) cavity D using a J 39200 DMM and measure the voltage reading.
  3. Turn the ignition to Run.

Does the J 39200 DMM read within the specified range?

11-14V

Go to Step 9

Go to Step 14

9

  1. Place the heated switch in the on position.
  2. Using a J 39200 DMM measure the voltage reading on CKT 1462 (LT BLU) cavity A of the heated seat switch.

Does the J 39200 DMM read within the specified range?

11-14V

Go to Step 10

Go to Step 15

10

  1. Locate the inline connector C305.
  2. Ensure the left seat switch is in the on position.
  3. Using a J 39200 DMM measure the voltage reading on CKT 1462 (LT BLU) cavity C.

Does the J 39200 DMM read within the specified range?

11-14V

Go to Step 11

Go to Step 16

11

Using a J 39200 DMM measure the voltage reading on CKT 2340 (ORN) cavity L of connector C305.

Does the J 39200 DMM read within the specified range?

11-14V

Go to Step 12

Go to Step 18

12

Using a J 39200 DMM measure the continuity on CKT 2350 (BLK) from C305 and ground.

Is continuity present on CKT 2350?

--

Go to Step 13

Go to Step 17

13

Replace the inoperative heated seat element and the electronic heated seat relay and wiring harness.

Is the repair complete?

--

Go to Heated Seats System Check

--

14

Locate and repair open in CKT 541 (BRN) between the inoperative heated seat switch and IGN 3 fuse (located in the left bussed electrical center LBEC). If OK, test for short to ground refer to Testing for Short to Ground in wiring systems.

Is the repair complete?

--

Go to Heated Seats System Check

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15

Replace the inoperative heated seat switch.

Is the repair complete?

--

Go to Heated Seats System Check

--

16

Locate and repair open in CKT 1505 (LT BLU/BLK) left seat, or CKT 1462 (LT BLU) right seat.

Is the repair complete?

--

Go to Heated Seats System Check

--

17

Locate and repair open in CKT 2350 (BLK) between the inoperative heated seat C399 (right), or C305 (left) and ground.

Is the repair complete?

--

Go to Heated Seats System Check

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18

  1. Locate and repair open in CKT 2340 (ORN) between the inoperative heated seat switch and the SEO 2 fuse (located in the underhood bussed electrical center).
  2. If no open is found, test for short to ground refer to Testing for Short to Ground in wiring systems.

Is the repair complete?

--

Go to Heated Seats System Check

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