Pinpoint Test V: An Individual Reversing Lamp Is Inoperative
Reversing Lamps
Pinpoint Tests
Pinpoint Test V: An Individual Reversing Lamp Is Inoperative
Refer to Wiring Diagram Set 93, Reversing Lamps for schematic and connector information. Diagrams By Number
Normal Operation
The PCM (gasoline engine) or the Transmission Control Module (TCM) (diesel engine) monitors the transmission. When the transmission is in REVERSE, the PCM or TCM sends a message to the Body Control Module (BCM) over the High Speed Controller Area Network (HS-CAN) indicating the transmission is in REVERSE. When the BCM receives the message indicating the transmission is in REVERSE, the BCM provides voltage to the reversing lamps.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Bulb holder (vehicles with pickup bed)
- Rear lamp assembly (vehicles without pickup bed)
PINPOINT TEST V: 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.
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V1 CHECK FOR VOLTAGE TO THE REVERSING LAMP
- Ignition OFF.
- Apply the parking brake.
- Disconnect: Inoperative Reversing Lamp.
- Ignition ON.
- Select REVERSE.
- For vehicles with a pickup bed, measure the voltage between the LH reversing lamp C451-1, circuit CLS28 (BU/WH), harness side and ground; or between the RH reversing lamp C461-1, circuit CLS28 (BU/WH), harness side and ground.
- For vehicles without a pickup bed, measure the voltage between the LH reversing lamp C423-1, circuit CLS28 (BU/WH), harness side and ground; or between the RH reversing lamp C422-1, circuit CLS28 (BU/WH), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to V2.
No
REPAIR circuit CLS28 (BU/WH) for an open. TEST the system for normal operation.
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V2 CHECK THE REVERSING LAMP GROUND CIRCUIT FOR AN OPEN
- For vehicles with a pickup bed, measure the voltage between the LH reversing lamp C451-1, circuit CLS28 (BU/WH), harness side and the LH reversing lamp C451-2, circuit GD176 (BK/WH), harness side; or between the RH reversing lamp C461-1, circuit CLS28 (BU/WH), harness side and the RH reversing lamp C461-2, circuit GD176 (BK/WH), harness side.
- For vehicles without a pickup bed, measure the voltage between the LH reversing lamp C423-1, circuit CLS28 (BU/WH), harness side and the LH reversing lamp C423-2, circuit GD176 (BK/WH), harness side; or between the RH reversing lamp C422-1, circuit CLS28 (BU/WH), harness side and the RH reversing lamp C422-2, circuit GD176 (BK/WH), harness side.
- Is the voltage greater than 10 volts?
Yes
INSTALL a new bulb holder (vehicles with a pickup bed) or rear lamp assembly (vehicles without a pickup bed). TEST the system for normal operation.
No
REPAIR circuit GD176 (BK/WH) for an open. TEST the system for normal operation.
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