Pinpoint Test X: An Individual Reversing Lamp Is Inoperative

Reversing Lamps

Pinpoint Test X: An Individual Reversing Lamp Is Inoperative

Refer to Wiring Diagram Set 93, Reversing Lamps for schematic and connector information [1][2]Diagrams By Number.

When the Body Control Module B (BCM-B) receives a message from the PCM indicating the transmission is in reverse, the BCM-B (Body Control Module B) supplies voltage to the reversing lamps.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors

- Rear lamp jumper harness

- BCM-B (Body Control Module B)

PINPOINT TEST X : AN INDIVIDUAL REVERSING LAMP IS INOPERATIVE

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

X1 CHECK FOR VOLTAGE TO THE REVERSING LAMP

- Ignition OFF.

- Disconnect: Inoperative Rear Lamp.

- Ignition ON.

- Apply the parking brake.

- Select REVERSE.

- Measure the voltage between the LH rear lamp C498-1, circuit CLS10 (GN/BN), harness side and ground; or between the RH rear lamp C499-1, circuit CLS11 (GY/VT), harness side and ground.





Is the voltage greater than 10 volts?

Yes
REPAIR or INSTALL a new rear lamp jumper harness. TEST the system for normal operation.

No
GO to X2.

X2 CHECK THE REVERSING LAMP VOLTAGE SUPPLY CIRCUIT FOR AN OPEN

- Ignition OFF.

- Measure the resistance between the LH reversing lamp C498-1, circuit CLS10 (GN/BN), harness side and between the BCM-B (Body Control Module B) C4368A-5, circuit CLS10 (GN/BN), harness side: or between the RH reversing lamp C499-1, circuit CLS11 (GY/VT), harness side and between the BCM-B (Body Control Module B) C4368A-17, circuit CLS11 (GY/VT), harness side.





Is the resistance less than 5 ohms?

Yes
GO to X3.

No
REPAIR circuit CLS10 (GN/BN) or CLS11 (GY/VT) for an open. TEST the system for normal operation.

X3 CHECK FOR CORRECT BCM-B (Body Control Module B) OPERATION

- Disconnect all the BCM-B (Body Control Module B) connectors.

- Check for:
- corrosion

- damaged pins

- pushed-out pins


- Connect all the BCM-B (Body Control Module B) connectors and make sure they seat correctly.

- Operate the system and verify the concern is still present.

Is the concern still present?

Yes
INSTALL a new BCM-B (Body Control Module B). TEST the system for normal operation.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.