GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Driver Seat Schematics

Connector End View Reference: Power Seat Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Operate the lumbar switch in all directions.

Does the system operate normally?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

  1. Install a scan tool.
  2. Observe the Lumbar/Bolster Switch parameter in the seat module Inputs/Outputs data list.
  3. Operate the lumbar switch in all directions.

Does the scan tool display the correct switch parameter in relation to the actual switch position?

Go to Step 6

Go to Step 4

4

  1. Disconnect the lumbar switch connector.
  2. Connect a test lamp from the battery voltage supply circuit terminal in the harness connector to ground.

Does the test lamp illuminate?

Go to Step 5

Go to Step 7

5

  1. Observe the Lumbar/Bolster Switch parameter in the seat module Inputs/Outputs data list.
  2. Connect a 3-amp fused jumper wire from the battery voltage supply circuit terminal to the inoperative switch signal circuit terminal in the lumbar switch harness connector.

Does the scan tool indicate the correct switch signal circuit is active?

Go to Step 10

Go to Step 8

6

  1. Disconnect the inoperative lumbar adjuster motor connector.
  2. Connect a test lamp between the adjuster motor control circuit terminals in the harness connector.
  3. Operate the appropriate lumbar switch in both directions.

Does the test lamp illuminate while the switch is pressed in both directions?

Go to Step 11

Go to Step 9

7

Test the battery voltage supply circuit to the lumbar switch for an open or short to ground. Refer to Circuit Testing and to Wiring Repairs .

Did you find and correct the condition?

Go to Step 16

Go to Step 12

8

Test the inoperative lumbar switch signal circuit for an open or short to ground. Refer to Circuit Testing and to Wiring Repairs .

Did you find and correct the condition?

Go to Step 16

Go to Step 12

9

Test the inoperative lumbar adjuster motor control circuits for an open or short to ground. Refer to Circuit Testing and to Wiring Repairs .

Did you find and correct the condition?

Go to Step 16

Go to Step 12

10

Inspect for poor connections at the harness connector of the lumbar switch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs .

Did you find and correct the condition?

Go to Step 16

Go to Step 13

11

Inspect for poor connections at the harness connector of the lumbar adjuster motor. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs .

Did you find and correct the condition?

Go to Step 16

Go to Step 14

12

Inspect for poor connections at the harness connector of the seat module. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs .

Did you find and correct the condition?

Go to Step 16

Go to Step 15

13

Replace the lumbar switch. Refer to Front Seat Lumbar Control Switch Replacement .

Did you complete the replacement?

Go to Step 16

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14

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

Did you complete the replacement?

Go to Step 16

--

15

Replace the seat module. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 16

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16

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3