GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Inspect the SEAT circuit breaker.

Is the SEAT circuit breaker open?

--

Go to Step 2

Go to Step 3

2

  1. Repair a short to ground in CKT 340.
  2. Inspect the system.

Is the symptom still present?

--

Go to Step 3

System OK

3

Inspect the H SEAT/LUM fuse.

Is the H SEAT/LUM fuse open?

--

Go to Step 4

Go to Step 5

4

  1. Repair a short to ground in CKT 2040.
  2. Inspect the system.

Is the symptom still present?

--

Go to Step 5

System OK

5

  1. Connect a test lamp.
  2. Backprobe between the driver seat lumbar adjuster switch connector terminal E and ground.

Does the test lamp light?

--

Go to Step 6

Go to Step 8

6

  1. Connect a test lamp.
  2. Backprobe between the driver seat lumbar adjuster switch connector terminal C and ground.

Does the test lamp light?

--

Go to Step 7

Go to Step 9

7

  1. Connect a test lamp.
  2. Backprobe between the driver seat lumbar adjuster switch connector terminals A and D.

Does the test lamp light?

--

Go to Step 11

Go to Step 10

8

  1. Repair the poor connection or open in CKT 2040.
  2. Inspect the system.

Is the symptom still present?

--

Go to Step 9

System OK

9

  1. Repair the poor connection or open in CKT 340 between C311 terminal A and S331.
  2. Inspect the system.

Is the symptom still present?

--

Go to Step 10

System OK

10

  1. Repair the poor connection or the open in CKT 750 between S330 and G301.
  2. Inspect the system.

Is the symptom still present?

--

--

System OK

11

  1. Replace the driver seat lumbar adjuster switch. Refer to Front Seat Lumbar Support Replacement .
  2. Inspect the system.

Is the symptom still present?

--

--

System OK