GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Lighting Systems Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

Verify that the backup lamps are always on.

Do the backup lamps operate normally?

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

Go to Step 3

3

  1. Turn the ignition switch to the RUN position.
  2. Disconnect the backup lamp switch (M/T), or the park/neutral position switch (A/T).

Do the backup lamps light?

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Go to Step 4

Go to Step 5

4

Locate and repair the short to B+ in one of the following locations. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

    • CKT 1324 (LT GRN)
    • CKT 1524 (GRY)
    • The underhood fuse block

Is the repair complete?

--

Go to Step 7

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5

Adjust the backup lamp switch (M/T) or the park/neutral position switch (A/T). Refer to Park/Neutral Position Switch Adjustment in Automatic Transmission

Is the repair complete?

--

Go to Step 7

Go to Step 6

6

Replace the appropriate switch:

    • The backup lamp switch. Refer to Backup Lamp Switch Replacement in Manual Transmission.
    • The park/neutral position switch. Refer to Park/Neutral Position Switch Replacement in Automatic Transmission.

Is the repair complete?

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Go to Step 7

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7

Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 3