GM Service Manual Online
For 1990-2009 cars only

Backup Lamps Inoperative Manual Transmission

Step

Action

Value(s)

Yes

No

1

Did you perform the Backup Lights System Check?

--

Go to Step  2

Go to Backup Lamp System Check

2

  1. Disconnect the backup lamps switch connector (manual) or the park/neutral position switch connector (automatic).
  2. Turn the ignition switch to the ON position.
  3. Connect a J 39200 Digital Multimeter (DMM) between terminal B of the back-up lamps switch or park/neutral position switch harness connector and ground.

Does the test lamp illuminate?

--

Go to Step  3

Go to Step  4

3

Connect the test lamp between terminal A and terminal B of the back-up lamps switch harness connector or between connector C2 terminal B and terminal F of the park/neutral position switch.

Does the test lamp illuminate?

--

Go to Step  5

Go to Step  6

4

Repair the open in CKT 539 between the fuse block and the back-up lamps switch or the park/neutral position switch.

Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Backup Lamp System Check

--

5

  1. Verify the adjustment of the back-up lamps switch or the park/neutral position switch.
  2. If the switch adjustment is acceptable, replace the switch.

Did you complete the repair?

--

Go to Backup Lamp System Check

--

6

Repair the open in CKT 24 between the back-up lamps switch and splice S400. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Backup Lamp System Check

--

Backup Lamps Inoperative Automatic Transmission

Step

Action

Value(s)

Yes

No

1

Did you perform the Backup Lights System Check?

--

Go to Step 2

Go to Backup Lamp System Check

2

  1. Disconnect the transaxle range switch connector.
  2. Turn the ignition switch to the RUN position.
  3. Connect the J 39200 Digital Multimeter (DMM) between terminal B of the transaxle range switch harness connector C2 and ground.

Does the test light illuminate?

--

Go to Step 3

Go to Step 4

3

Connect a Fused Jumper between terminal F and terminal B of the transaxle range switch harness connector C2.

Do the Back Up lamps illuminate?

--

Go to Step 5

Go to Step 6

4

Repair the open in CKT 539 between the fuse block and the transaxle range switch. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Backup Lamp System Check

--

5

  1. Verify the adjustment of the transaxle range switch.
  2. If the switch adjustments are acceptable, replace the transaxle range switch. Refer to Park/Neutral Position Switch Replacement in Automatic Transaxle - 3T40 or Park/Neutral Position Switch Replacement in Automatic Transaxle - 4T40-E.

Did you complete the repair?

--

Go to Backup Lamp System Check

--

6

Repair the open in CKT 24 between the transaxle range switch and splice S400. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Backup Lamp System Check

--