GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Was the entire backup lights system check performed?

--

Go to Step 2

Go to Backup Lamp System Check

2

Inspect to determine if the backup lamps are damaged or open.

Are the backup lamps damaged or open?

--

Go to Step 3

Go to Step 4

3

Replace the backup lamps. Refer to Backup Lamp Bulb Replacement

Is the repair complete?

--

Go to Step 17

--

4

  1. Place the ignition in the RUN position.
  2. Set the park brake.
  3. Apply the brake pedal.
  4. Place the transmission in the REVERSE position.
  5. Backprobe with a test light from connector C400 terminal F to ground.

Does the test light illuminate?

--

Go to Step 5

Go to Step 6

5

Connect a test light between the LH backup lamp connector terminals A and G.

Does the test light illuminate?

--

Go to Step 3

Go to Step 15

6

Determine if the vehicle has a manual transmission or an automatic transmission.

Does the vehicle have a manual transmission?

--

Go to Step 7

Go to Step 8

7

Connect a test light between the backup lamp switch connector terminal B and ground.

Does the test light illuminate?

--

Go to Step 9

Go to Step 10

8

Backprobe with a test light from park/neutral position switch connector terminal C to ground.

Does the test light illuminate?

--

Go to Step 13

Go to Step 12

9

Repair a poor connection or open in circuit 24.

Is the repair complete?

--

Go to Step 17

--

10

  1. Make sure the vehicle is in the PARK position.
  2. Turn the ignition swich to the OFF position.
  3. Disconnect the backup lamp switch.
  4. Turn the ignition switch to the RUN position.
  5. Probe with a test light from the backup lamp connector terminal A to ground.

Does the test light illiuminate?

--

Go to Step 11

Go to Step 12

11

Replace the backup lamp switch. Refer to Backup Lamp Switch Replacement Backup Lamp Switch Replacement

Is the repair complete?

--

Go to Step 17

--

12

Repair the open or poor connection in circuit 141.

Is the repair complete?

--

Go to Step 17

--

13

Connect a test light between the park/neutral position switch connector terminal D and ground.

Does the test light illuminate?

--

Go to Step 9

Go to Step 14

14

Adjust or replace the park/neutral position switch. Refer to Park/Neutral Position Switch Replacement

Is the repair complete?

--

Go to Step 17

--

15

Connect a test light between the LH backup lamp connector terminals A and ground.

Does the test light illuminate?

--

Go to Step 16

Go to Step 9

16

Repair a poor connection or open in circuit 1250.

Is the repair complete?

--

Go to Step 17

--

17

  1. Turn the ignition swich to the OFF position.
  2. Reconnect all connectors/components removed.

Have all repairs been made?

--

Go to Backup Lamp System Check

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