PINPOINT TEST AK : The Trailer Reversing Lamps Are Inoperative
NOTE:
Before beginning diagnostics, visually inspect the trailer tow connector mounted on the bumper for signs of corrosion or damage. Repair or install a new trailer tow connector as required.
- AK1 CHECK FOR VOLTAGE THROUGH THE TRAILER TOW CONNECTOR
- Apply the parking brake.
- Ignition ON.
- Select REVERSE.
Is the voltage greater than 11 volts?
Yes The vehicle is operating correctly. SEND the trailer to an authorized camper/trailer repair facility. No VERIFY the BJB fuse 60 (10A) is OK. If OK, GO to AK2. If not OK, REFER to the OEM ELECTRICAL WIRING DIAGRAM INTRODUCTION to identify the possible causes of the circuit short. - AK2 CHECK FOR VOLTAGE TO THE TRAILER TOW CONNECTOR (VEHICLE HARNESS)
- Ignition OFF.
- Disconnect: Trailer Tow Connector.
- Ignition ON.
- Select REVERSE.
- Measure:
Positive Lead Measurement / Action Negative Lead C4099-7 Ground
Is the voltage greater than 11 volts?
Yes INSTALL a new trailer tow connector. TEST the system for normal operation. No GO to AK3. - AK3 CHECK THE TRAILER TOW REVERSING LAMP RELAY
- Ignition OFF.
- Disconnect: Trailer Tow Parking Lamp Relay.
- Substitute a known good relay.
- Ignition ON.
- Select REVERSE.
- Measure:
Positive Lead Measurement / Action Negative Lead C4099-7 Ground
Is the voltage greater than 11 volts?
Yes REMOVE the known good relay. INSTALL a new trailer tow reversing lamp relay. No REMOVE the known good relay. GO to AK4. - AK4 CHECK THE TRAILER TOW REVERSING LAMP RELAY COIL VOLTAGE SUPPLY CIRCUIT FOR AN OPEN
- Select REVERSE.
- Measure:
Positive Lead Measurement / Action Negative Lead Trailer Tow Reversing Lamp Relay Pin 1 Ground
Is the voltage greater than 11 volts?
Yes GO to AK5. No REPAIR the circuit. - AK5 CHECK THE TRAILER TOW REVERSING LAMP RELAY BJB VOLTAGE SUPPLY CIRCUIT FOR AN OPEN
- Select PARK.
- Ignition OFF.
- Measure:
Positive Lead Measurement / Action Negative Lead Trailer Tow Reversing Lamp Relay Pin 3 Ground
Is the voltage greater than 11 volts?
Yes GO to AK6. No REPAIR the circuit. - AK6 CHECK THE TRAILER TOW REVERSING LAMP RELAY GROUND CIRCUIT FOR AN OPEN
- Measure:
Positive Lead Measurement / Action Negative Lead Trailer Tow Reversing Lamp Relay Pin 3 Trailer Tow Reversing Lamp Relay Pin 2
Is the voltage greater than 11 volts?
Yes REPAIR the trailer tow reversing lamp relay output circuit to the trailer tow connector for an open. No REPAIR the trailer tow reversing lamp relay ground circuit for an open. - Measure:
