For 1990-2009 cars

## Object Alarm Indicator 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
--- | --- | --- | --- | ---
Object Alarm Indicator 8-Volts Reference | 1, 2 | 1, 2 | 1, 2 | --
Object Alarm Indicator Control Circuit | 1, 3 | 1, 2 | 1, 2 | --
1. Rear Object Detection System Inoperative. 2. Object Alarm Indicator Inoperative. 3. Object Alarm Indicator Always ON.

### Circuit/System Description

The object alarm module supplies 8 volts to the object alarm indicator through the 8-volts reference circuit and ground through the signal circuit. The buzzer sound produced by the object alarm indicator indicates how close the vehicle rear bumper is to an object.

### Diagnostic Aids

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

Important: The recommended vehicle reversing speed is below five kph.

• | Attached Object- The object alarm module is detecting an object that is attached to the vehicle. Common items such as trailer, caravan or a bicycle rack may cause this concern.

• | Sensor Alignment - damage to the rear of the vehicle or a misaligned sensor may cause this concern. If the vehicle is damaged in a manner that causes the sensor to detect the bumper itself, the object alarm indicator will produce continuous buzzer sound. Carefully inspect the bumper, bumper mounting surface, and sensor retainers before continuing with normal diagnosis.

• | Sensor Disturbance - An outside interference is causing sensor movement. Such interference may be caused a heavy pounding, like that of a nearby jackhammer, or large changes in pressure, such as a large truck's air brakes.

• | Snow/Ice/Mud - One or more of the sensors is being blocked by snow, mud, ice, or other debris.

• | Sensor Ring Time - Each of the sensors emits an ultrasonic frequency. This frequency is reflected off of nearby objects, bouncing it back towards the vehicle bumper where it is received by the sensor. The time between the sensor emitting the frequency and the sensor receiving the reflection, known as sensor ring time, is used to determine the distance of nearby objects. Paint on a sensor may cause an excessive sensor ring time. Make sure the sensors are not painted.

### Reference Information

#### Schematic Reference

Object Detection Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Rear Object Detection Description and Operation Object Detection Description and Operation

#### Component View Reference

Object Detection Component Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

### Circuit/System Verification

1. Ignition ON, engine OFF, Park brake ON, transmission in REVERSE, individually place a suitable object behind each sensor. Verify the correct operation of each sensor.

2. Visibly inspect the warning buzzer disable switch and ensure that the warning buzzer is not disabled.

### Circuit/System Testing

1. Ignition OFF, disconnect the connector at the object alarm indicator.
2. Ignition ON, engine OFF, Park brake ON, transmission in REVERSE, test for 7.5-8.5 volts between the 8-volts reference circuit terminal 1 and ground.

⇒ | If greater than the specified range, test the 8-volts reference circuit for a short to voltage.

⇒ | If less than the specified range, test the 8-volts reference circuit for a short to ground or an open/high resistance.

⇒ | If the circuit tests normal, replace the object alarm module.

3. Ignition ON, engine OFF, park brake ON, transmission in REVERSE, place a suitable object less than 0.45 m behind each sensor, test for 7.5-8.5 volts between the 8-volts reference circuit terminal 1 and control circuit terminal 2.

⇒ | If greater than the specified range, test the control circuit for a short to voltage.

⇒ | If less than the specified range, test the control circuit for a short to ground or an open/high resistance.

⇒ | If the control circuit tests normal, replace the object alarm module.

4. Ignition OFF, connect the connector at the object alarm indicator.
5. Ignition ON, engine OFF, park brake ON, transmission in REVERSE, place a suitable object less than 0.45 m behind each sensor.

⇒ | Object alarm indicator should be activated continuously. If not, replace the object alarm indicator.

### Repair Instructions

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

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.