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For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1999 🢒 Envoy - 4WD 🢒 Body and Accessories 🢒 Lighting Systems 🢒 Backup Lamp Inoperative - One Lamp

Backup Lamp Inoperative - One Lamp Pickup

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. Connect a J 39200 digital multimeter (DMM) between CKT 1324 (LT GRN) at the lamp socket and ground.
  2. Turn the ignition switch to the RUN position.
  3. Set the parking brake.
  4. Place the transmission in the REVERSE position.

Is voltage present?

Battery Voltage

Go to Step 4

Go to Step 3

3

Locate and repair the open in CKT 1324 (LT GRN) at splice pack SP400.

Is the repair complete?

--

Go to Backup Lamp System Check

--

4

Connect the J 39200 DMM between CKT 1324 (LT GRN) at the lamp socket and CKT 1750/2250 (BLK) at the lamp socket.

Is voltage present?

Battery Voltage

Go to Step 5

Go to Step 8

5

Inspect the lamp socket for damaged or corroded terminals.

Are the lamp socket terminals damaged or corroded?

--

Go to Step 6

Go to Step 7

6

Repair or replace the lamp socket as needed.

Is the repair complete?

--

Go to Backup Lamp System Check

--

7

Replace the bulb.

Is the repair complete?

--

Go to Backup Lamp System Check

--

8
  1. Locate and repair the open in CKT 1750/2250 (BLK) or a corroded ground contact.
  2. Verify proper connection at splice pack SP402 or SP401.

Is the repair complete?

--

Go to Backup Lamp System Check

--

Backup Lamp Inoperative - One Lamp Utility

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. Connect a J 39200 digital multimeter (DMM) between CKT 1324 (LT GRN) at the lamp socket and ground.
  2. Turn the ignition switch to the ON position.
  3. Set the parking brake.
  4. Place the transmission in the REVERSE position.

Is voltage present?

Battery Voltage

Go to Step 4

Go to Step 3

3

Locate and repair the open in CKT 1324 (LT GRN).

Is the repair complete?

--

Go to Backup Lamp System Check

--

4

Connect the J 39200 DMM between CKT 1324 (LT GRN) and CKT 150 (BLK) at the lamp socket.

Is voltage present?

Battery Voltage

Go to Step 5

Go to Step 8

5

Inspect the lamp socket for damaged or corroded terminals.

Are the lamp socket terminals damaged or corroded?

--

Go to Step 6

Go to Step 7

6

Repair or replace the lamp socket as needed.

Is the repair complete?

--

Go to Backup Lamp System Check

--

7

Replace the bulb.

Is the repair complete?

--

Go to Backup Lamp System Check

--

8

Locate and repair the open in CKT 150 (BLK).

Is the repair complete?

--

Go to Backup Lamp System Check

--