GM Service Manual Online
For 1990-2009 cars only

Lumbar Support Inoperative w/o A45

Step

Action

Value(s)

Yes

No

Schematic Reference: Lumbar Support Schematics

Connector End View Reference: Power Seat Connector End Views

1

Did you review the power seat operation and perform the necessary inspection?

--

Go to Step 2

Go to Symptoms - Seats

2

Verify that the Lumbar Support Inoperative complaint is present.

Does the lumbar support system operate as described in the system description and operation?

--

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

Go to Step 3

3

Measure the voltage from the battery positive voltage circuit of the lumbar switch to a good ground.

Does the voltage measure within specified range?

10-15 V

Go to Step 4

Go to Step 6

4

Measure the voltage from the battery positive voltage circuit of the lumbar switch to the ground circuit of the lumbar switch.

Does the voltage measure within specified range?

10-15 V

Go to Step 5

Go to Step 7

5

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

Did you find and correct the condition?

--

Go to Step 9

Go to Step 8

6

Repair the open in the battery positive voltage circuit and the lumbar switch. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 9

--

7

Repair the open in the ground circuit of the lumbar switch. Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Step 9

--

8

Replace the lumbar switch. Refer to Lumbar Switch Replacement .

Did you complete the replacement?

--

Go to Step 9

--

9

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2

Lumbar Support Inoperative with A45

Step

Action

Value(s)

Yes

No

Schematic Reference: Lumbar Support Schematics

Connector End View Reference: Power Seat Connector End Views

1

Did you perform the Diagnostic System Check - Power Seat Systems?

--

Go to Step 2

Go to Diagnostic System Check - Power Seat Systems

2

Verify that the Lumbar Support Inoperative complaint is present.

Does the lumbar support system operate as described in the system description and operation?

--

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

Go to Step 3

3

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the Lumbar Switches parameter in the Memory Seat Module data list.
  4. Operate the lumbar switch in the UP direction.

Does the scan tool display Up?

--

Go to Step 7

Go to Step 4

4

Measure the voltage from the battery positive voltage circuit of the lumbar switch to a good ground.

Does the voltage measure within the specified range?

9-16 V

Go to Step 5

Go to Step 8

5

  1. Probe one of the lumbar switch signal circuits of the memory seat module with a test lamp that is connected to a good ground.
  2. Operate the appropriate lumbar switch.

Does the test lamp illuminate?

--

Go to Step 7

Go to Step 6

6

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

Did you find and correct the condition?

--

Go to Step 11

Go to Step 9

7

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

Did you find and correct the condition?

--

Go to Step 11

Go to Step 10

8

Repair the open in the battery positive voltage circuit of the lumbar switch. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 11

--

9

Replace the lumbar switch. Refer to Lumbar Switch Replacement .

Did you complete the replacement?

--

Go to Step 11

--

10

Replace the memory seat module. Refer to Memory Seat Control Module Replacement .

Did you complete the replacement?

--

Go to Step 11

--

11

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2