For 1990-2009 cars

## Trailer Lamps Malfunction Holden Genuine Accessory

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using the diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category Circuit/System Description.

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Turn Signal Lamps-Left Signal | 1 | 1 | 1 | --
Backup Lamps Signal | 3 | 3 | 3 | --
Ground | 1, 2, 3, 4, 5 | 1, 2, 3, 4, 5 | 1, 2, 3, 4, 5 | --
Turn Signal Lamps-Right Signal | 2 | 2 | 2 | --
Stop Lamps Signal | 4 | 4 | 4 | --
Park Lamps Signal | 5 | 5 | 5 | --
1. Left Turn Signal Lamp Malfunction. 2. Right Turn Signal Lamp Malfunction. 3. Backup Lamps Malfunction. 4. Stop Lamps Malfunction. 5. Park Lamps Malfunction.

### Circuit/System Description

The trailer patch harness connectors are connected between the designated inline connectors of the exterior lighting system. This connection allows integration of the lighting system of the trailer to the exterior lighting of the vehicle. The wiring harness of the trailer lamps is connected to the vehicle through the trailer connector. Refer to Trailer Connector/Provision Component Views.

If the vehicle is fitted with a genuine Holden object detection system, the ground circuit of this system is connected to a Reed switch in the trailer connector. Opening the trailer connector cover actuates the switch and disables the rear object detection system.

### Diagnostic Aids

The following is a brief description of potential causes which may aid in diagnosis:

• | Make sure to inspect the inoperative bulbs for broken filament or corroded terminal connections.

• | Make sure to check connectors for correct mating and for corrosions that will prevent proper electrical connections.

### Reference Information

#### Schematic Reference

Trailer Connector/Provision Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Exterior Lighting Systems Description and Operation

#### Component View Reference

Trailer Connector/Provision Component Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

### Circuit/System Verification

#### Turn Signal Lamps - Left

Ignition ON, left turn signal lamps switch ON, the left turn signal lamps of the vehicle should be blinking. If the left turn signal lamps do not blink, refer to Turn Signal Lamps and/or Indicators Inoperative.

#### Turn Signal Lamps - Right

Ignition ON, right turn signal lamps switch ON, the right turn signal lamps of the vehicle should be blinking. If the left turn signal lamps do not blink, refer to Turn Signal Lamps and/or Indicators Inoperative.

#### Backup lamps

Ignition ON, park brake ON, transmission in REVERSE, the backup lamps of the vehicle should illuminate. If the backup lamps do not illuminate, refer to Backup Lamps Inoperative.

#### Stop lamps

Ignition ON, brake pedal pressed, the stop lamps of the vehicle should illuminate only when the brake pedal is pressed. If the stop lamps do not function correctly, refer to Stop Lamps Inoperative or Stop Lamps Always On.

#### Park Lamps

Ignition ON, park lamps switch ON, the park lamps of the vehicle should illuminate. If the park lamps do not illuminate, refer to Park, License, and Tail Lamps Inoperative.

### Circuit/System Testing

#### Turn Signal Lamps - Left

1. Ignition OFF, disconnect the trailer connector.
2. Test for less than 1.0 ohm between the ground circuit terminal 3 and ground.

⇒ | If greater than the specified value, test the ground circuit for an open/high resistance.

#### Turn Signal Lamps - Right

1. Ignition OFF, disconnect the trailer connector.
2. Test for less than 1.0 ohm between the ground circuit terminal 3 and ground.

⇒ | If greater than the specified value, test the ground circuit for an open/high resistance.

3. Ignition ON, right turn signal lamps switch ON, verify that a test lamp is blinking when connected between the signal circuit terminal 4 and ground circuit terminal 3.

⇒ | If the test lamp is not blinking, test the signal circuit for a short to voltage, a short to ground or an open/high resistance.

#### Backup lamps

1. Ignition OFF, disconnect the trailer connector.
2. Test for less than 1.0 ohm between the ground circuit terminal 3 and ground.

⇒ | If greater than the specified value, test the ground circuit for an open/high resistance.

3. Ignition ON, park brake ON, transmission in REVERSE, verify that a test lamp illuminates when connected between the signal circuit terminal 2 and ground circuit terminal 3.

⇒ | If the test lamp does not illuminate, test the signal circuit for a short to ground or an open/high resistance.

#### Stop lamps

1. Ignition OFF, disconnect the trailer connector.
2. Test for less than 1.0 ohm between the ground circuit terminal 3 and ground.

⇒ | If greater than the specified value, test the ground circuit for an open/high resistance.

3. Ignition ON, brake pedal pressed, verify that a test lamp illuminates when connected between the signal circuit terminal 6 and ground circuit terminal 3.

⇒ | If the test lamp does not illuminate, test the signal circuit for a short to ground or an open/high resistance.

#### Park Lamps

1. Ignition OFF, disconnect the trailer connector.
2. Test for less than 1.0 ohm between the ground circuit terminal 3 and ground.

⇒ | If greater than the specified value, test the ground circuit for an open/high resistance.

3. Ignition ON, park lamps switch ON, verify that a test lamp illuminates when connected between the signal circuit terminal 7 and ground circuit terminal 3.

⇒ | If the test lamp does not illuminate, test the signal circuit for a short to ground or an open/high resistance.

### Repair Instructions

For component removal and installation refer to the accessory fitting instructions.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.