B1017-19

B1017-19-REVERSE LAMP - OVER CURRENT

For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The BCM receives a communication network message to indicate that the vehicle is in reverse. Once the BCM is informed that the vehicle is in reverse, it provides a voltage output through the backup lamp driver circuit. The same BCM driver circuit connects to both the Left and Right Backup Lamps. A ground path for the lamps is present through the harness to the body sheet metal. For additional information on the Backup Lamps operation, Exterior Lamps - Operation.

- When Monitored:
With the backup lamps on.

- Set Condition:
When the Body Control Module (BCM) detects greater than expected current draw on the (L15) Left Backup Lamp Driver circuit or (L16) Right Backup Lamp Driver circuit.





1. CHECK FOR AN INTERMITTENT CONDITION

NOTE: The same BCM driver circuit provides voltage to both the left and right backup lamps. If either the left or right backup lamp is functional, the BCM is not the cause of the concern.

1. Turn the ignition on.
2. With the scan tool, clear all DTCs.
3. With the brakes firmly applied, shift the gear selector into REVERSE.
4. With the scan tool, read DTCs.

Does the scan tool display this DTC as active?

Yes

- Go To 4

No

- Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

2. CHECK FOR LEFT BACKUP LAMP FOR CORRECT OPERATION
1. Shift the gear selector into PARK.
2. Turn the ignition off.
3. Disconnect the Left Tail Lamp Assembly C1 harness connector.
4. Turn the ignition on.
5. With the brakes firmly applied, shift the gear selector into REVERSE.
6. With the scan tool, read DTCs.

Does the scan tool display this DTC as active?

Yes

- Go To 3

No

- Replace the Left Backup Lamp Bulb. Tail Stop Turn Lamp - Removal.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

3. CHECK FOR RIGHT BACKUP LAMP FOR CORRECT OPERATION
1. Shift the gear selector into PARK.
2. Turn the ignition off.
3. Disconnect the Right Tail Lamp Assembly C1 harness connector.
4. Turn the ignition on.
5. With the brakes firmly applied, shift the gear selector into REVERSE.
6. With the scan tool, read DTCs.

Does the scan tool display this DTC as active?

Yes

- Go To 4

No

- Replace the Right Backup Lamp Bulb. Tail Stop Turn Lamp - Removal.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

4. CHECK THE (L15) LEFT BACKUP LAMP DRIVER CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS
1. Turn the ignition off.
2. Disconnect the BCM C2 harness connector.
3. Measure the resistance between ground and the (L15) Left Backup Lamp Driver circuit at the Left Tail Lamp Assembly C1 harness connector.

Is the resistance above 10k Ohms?

Yes

- Go To 5

No

- Repair the short to ground in the (L15) Left Backup Lamp Driver circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

5. CHECK THE (L16) RIGHT BACKUP LAMP DRIVER CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS
1. Measure the resistance between ground and the (L16) Right Backup Lamp Driver circuit at the Right Tail Lamp Assembly C1 harness connector.

Is the resistance above 10k Ohms?

Yes

- Replace the BCM. Body Control Module - Removal.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Repair the short to ground in the (L16) Right Backup Lamp Driver circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.