Diagnostic Routine AH

Diagnostic Routine AH

Diagnostic Overview

All The Trailer 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

The trailer tow connector is provided ground through a dedicated circuit. This circuit is the shared ground for all of the trailer lamps.

All of the trailer lamp relays located in the BJB (Battery Junction Box) share a common ground.

Visual Inspection and Diagnostic Pre-checks

- Inspect the trailer tow connector for damage.

Pinpoint Test

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.

1. CHECK THE RELAY GROUND CIRCUIT FOR AN OPEN

1. Ignition OFF.

2. Disconnect: Trailer Tow Parking Lamp Relay.

3. Measure:





Is the voltage greater than 11 volts?








2. CHECK THE TRAILER TOW GROUND CIRCUIT FOR CONTINUITY TO GROUND

1. For the 4-pin connector, measure:





2. For the 7-pin connector, measure:





Is the resistance less than 3 ohms?








3. CHECK THE TRAILER TOW GROUND CIRCUIT FOR AN OPEN

1. Disconnect: Trailer Tow Connector.

2. Measure:





Is the resistance less than 3 ohms?