Diagnostic Routine AJ
Diagnostic Routine AJ
Diagnostic Overview
The Trailer Parking Lamps Are Inoperative
Refer to Wiring Diagram Set 11 for schematic and connector information Electrical Diagrams.
Refer to Wiring Diagram Set 95 for schematic and connector information Electrical Diagrams.
Normal Operation and Fault Conditions
REFER to Trailer Parking Lamps .
Visual Inspection and Diagnostic Pre-checks
- Inspect the BJB (Battery Junction Box) fuse 84 (20A).
- Inspect the vehicle rear parking lamps for correct operation.
- Inspect the trailer tow connector for damage.
Pinpoint Test
NOTE: Before beginning diagnostics, visually inspect the trailer tow connector for signs of corrosion or damage. Repair or install a new trailer tow connector as required.
1. CHECK FOR VOLTAGE THROUGH THE TRAILER TOW CONNECTOR
1. Ignition OFF.
2. Place the headlamp switch in the parking lamps on position.
3. For the 4-pin connector, measure:
4. For the 7-pin connector, measure:
Is the voltage greater than 11 volts?
2. CHECK FOR VOLTAGE TO THE TRAILER TOW CONNECTOR (7-PIN)
1. Disconnect: Trailer Tow Connector.
2. Measure:
Is the voltage greater than 11 volts?
3. CHECK THE TRAILER TOW PARKING LAMP RELAY
1. Place the headlamp switch in the off position.
2. Disconnect: Trailer Tow Parking Lamp Relay.
3. Substitute a known good relay.
4. Place the headlamp switch in the parking lamps on position.
5. For the 4-pin connector, measure:
6. For the 7-pin connector, measure:
Is the voltage greater than 11 volts?
4. CHECK THE TRAILER TOW PARKING LAMP RELAY COIL VOLTAGE SUPPLY CIRCUIT FOR AN OPEN
1. Measure:
Is the voltage greater than 11 volts?
5. CHECK THE TRAILER TOW PARKING LAMP RELAY BJB (Battery Junction Box) VOLTAGE SUPPLY CIRCUIT FOR AN OPEN
1. Place the headlamp switch in the off position.
2. Measure:
Is the voltage greater than 11 volts?
6. CHECK THE TRAILER TOW PARKING LAMP RELAY GROUND CIRCUIT FOR AN OPEN
1. Measure:
Is the voltage greater than 11 volts?
