GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

Schematic Reference: Lumbar Support Schematics

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

1

Did you review the Lumbar Support Description and Operation?

--

Go to Step 2

Go to Lumbar Support Description and Operation

2

Operate the Lumbar/Bolster system.

Does the system operate normally?

--

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

Are both the lumbar and the bolster inoperative?

--

Go to Step 4

Go to Step 6

4

  1. Disconnect the inoperative lumbar/bolster switch connector.
  2. Connect a test lamp between battery positive voltage at the inoperative lumbar/bolster switch connector and good ground.

Does the test lamp illuminate?

--

Go to Step 5

Go to Step 10

5

Connect a test lamp between the ground circuit at the inoperative lumbar/bolster switch connector and battery positive voltage.

Did the test lamp illuminate?

--

Go to Step 8

Go to Step 11

6

  1. Disconnect the inoperative motor.
  2. Using a test lamp connected between the motor control circuits, operate the lumbar/bolster switch in the appropriate directions and observe the test lamp.

Does the test lamp illuminate for each motor direction available from the lumbar/bolster switch?

--

Go to Step 9

Go to Step 7

7

Test the inoperative motor control circuits for a open or short to ground. Refer to Circuit Testing in Wiring Repairs.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 8

8

Inspect for poor connections at the lumbar/bolster switch connector. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 13

9

Inspect for poor connections at the motor connector. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 12

10

Repair the open in the battery positive voltage circuit for the inoperative lumbar/bolster switch. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 14

--

11

Repair the open in the ground circuit for the inoperative lumbar/bolster switch. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 14

--

12

Replace the inoperative motor. Refer to Front Seat Lumbar Support Replacement .

Did you complete the replacement?

--

Go to Step 14

--

13

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

Did you complete the replacement?

--

Go to Step 14

--

14

Operate the system to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3