Pinpoint Test W: The Individual Reversing Lamp Is Inoperative

WARNING: This page is about a different car, the 2010 Mercury Mariner and 2010 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.

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

W1 CHECK FOR VOLTAGE TO THE REVERSING LAMP
- Ignition OFF.
- Disconnect: Inoperative Reversing Lamp.
- Apply the parking brake.
- Ignition ON.
- Select REVERSE.
- Measure the voltage between the LH reversing lamp C451-2, circuit CBB07 (GN/BU), harness side and ground; or between the RH reversing lamp C461-2, circuit CBB07 (GN/BU), harness side and ground.
  
  Fig 1: Measuring Voltage Between LH Reversing Lamp C451-2, Circuit CBB07 (GN/BU), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes: GO to W2 .
- No: REPAIR circuit CBB07 (GN/BU) for an open. TEST the system for normal operation.
W2 CHECK FOR VOLTAGE TO THE REVERSING LAMP USING THE CONNECTOR GROUND
- Measure the voltage between the LH reversing lamp C451-2, circuit CBB07 (GN/BU), harness side and the LH reversing lamp C451-1, circuit GD182 (BK/GY), harness side; or between the RH reversing lamp C461-2, circuit CBB07 (GN/BU), harness side and the RH reversing lamp C461-1, circuit GD182 (BK/GY), harness side.
  
  Fig 2: Checking Voltage To Reversing Lamp Using Connector Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes: INSTALL a new bulb holder. TEST the system for normal operation.
- No: REPAIR circuit GD182 (BK/GY) for an open. TEST the system for normal operation.