Pinpoint Test Q: An Individual Reversing Lamp Is Inoperative

Reversing Lamps

Pinpoint Test Q: An Individual Reversing Lamp Is Inoperative


Normal Operation

When the reversing lamp relay is energized, voltage is routed to the reversing lamps.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors

- Bulb holder

PINPOINT TEST Q : 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.

Q1 CHECK FOR VOLTAGE TO THE INOPERATIVE REVERSING LAMP

- Ignition OFF.

- Disconnect: Inoperative Reversing Lamp.

- Apply the parking brake.

- Ignition ON.

- Select REVERSE.

- Measure the voltage between the LH reversing lamp C451-3, circuit CLS28 (BU/WH), harness side and ground; or between the RH reversing lamp C461-3, circuit CLS28 (BU/WH), harness side and ground.





Is the voltage greater than 10 volts?

Yes
GO to Q2.

No
REPAIR circuit CLS28 (BU/WH) for an open. TEST the system for normal operation.

Q2 CHECK FOR VOLTAGE TO THE INOPERATIVE REVERSING LAMP USING THE LAMP GROUND PIN

- Measure the voltage between the LH reversing lamp C451-3, circuit CLS28 (BU/WH), harness side and the LH reversing lamp C451-1, circuit GD149 (BK/GY), harness side; or between the RH reversing lamp C461-3, circuit CLS28 (BU/WH), harness side and the RH reversing lamp C461-1, circuit GD149 (BK/GY), harness side.





Is the voltage greater than 10 volts?

Yes
INSTALL a new bulb holder. TEST the system for normal operation.

No
REPAIR circuit GD149 (BK/GY) for an open. TEST the system for normal operation.