GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

IMPORTANT: This table assumes that the mechanical systems are clear and free of obstructions.

1

Are both the lumbar and bolster inoperative?

--

Go to Step 2

Go to Step 4

2

  1. Disconnect the inoperative lumbar/bolster switch connector.
  2. Connect a test lamp between CKT 1440 (ORN) cavity A and ground.

Does the test lamp light?

--

Go to Step 3

Go to Step 6

3

Connect a test lamp between CKT 2350 (BLK) cavity C and battery positive voltage.

Does the test lamp light?

--

Go to Step 4

Go to Step 7

4

  1. Ensure the inoperative lumbar/bolster switch is connected to the harness.
  2. Backprobe a fuse jumper between the respective lumbar/bolster switch terminals and ground.
  3. Backprobe a fused jumper between CKT 1440 (ORN) cavity A and respective lumbar/bolster switch terminals.
  4. Reverse jumper position on switch terminals.
  5. Observe motor operation.

Does the lumbar/bolster motor operate in both directions?

--

Go to Step 5

Go to Step 8

5

Replace the inoperative lumbar/bolster switch. Refer to Lumbar Switch Replacement .

Is the repair complete?

--

Go to Lumbar Support System Check

--

6

  1. Locate and repair open in CKT 1440 (ORN) between the inoperative seat switch and the seat circuit breaker (located in the left bussed electrical center LBEC).
  2. If no open is found, test the seat circuit breaker for proper operation refer to Circuit Protection - Circuit Breakers and Testing for Short to Ground in wiring systems.

Is the repair complete?

--

Go to Lumbar Support System Check

--

7

Locate and repair open in CKT 2350 (BLK) between the seat switch and ground.

Is the repair complete?

--

Go to Lumbar Support System Check

--

8

Replace the inoperative lumbar/bolster motor and wiring harness. Refer to Front Seat Lumbar Support Replacement .

Is the repair complete?

--

Go to Lumbar Support System Check

--