GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Power Seat Systems Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Power Seat Systems

2

Verify that the lumbar support is inoperative.

Does the lumbar support operate normally?

--

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

Go to Step 3

3

  1. Disconnect the lumbar switch connector.
  2. Test the lumbar switch feed circuit for voltage. Refer to Circuit Testing in wiring systems.

Does the voltage measure near the specified value?

B+

Go to Step 4

Go to Step 8

4

Test between the lumbar switch feed and ground circuits for voltage. Refer to Circuit Testing in wiring systems.

Does the voltage measure near the specified value?

B+

Go to Step 5

Go to Step 10

5

Test the lumbar motor control circuits for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in wiring systems.

Did you find and correct the condition?

--

Go to Step 12

Go to Step 6

6

  1. Reconnect the lumbar switch connector.
  2. Test the lumbar motor control circuits for voltage. Refer to Circuit Testing in wiring systems.
  3. Operate the lumbar switch between the IN and OUT position.

Is voltage present?

--

Go to Step 7

Go to Step 11

7

Replace the lumbar motor. Refer to Front Seat Back Replacement .

Did you complete the replacement?

--

Go to Step 12

--

8

Test for a high resistance or an open in the lumbar switch feed circuit. Refer to Circuit Testing and Wiring Repairs in wiring systems.

Did you find and correct the condition?

--

Go to Step 12

Go to Step 9

9

Test for a low resistance or a short to ground in the lumbar motor control circuits. Refer to Circuit Testing and Wiring Repairs in wiring systems.

Did you find and correct the condition?

--

Go to Step 12

--

10

Test for a high resistance or an open in the lumbar switch ground circuit. Refer to Circuit Testing and Wiring Repairs in wiring systems.

Did you find and correct the condition?

--

Go to Step 12

Go to Step 11

11

Replace the lumbar switch. Refer to Lumbar Switch Replacement .

Did you complete the replacement?

--

Go to Step 12

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12

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3