For 1990-2009 cars

## Rear Park Assist Sensors Faulty or Inoperative Genuine Accessory

### Diagnostic Fault Information

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

### Circuit/System Description

The parking sensors, situated in the rear bumper operate both as transmitters and receivers of ultrasonic signals. When the system is active and these ultrasonic sound waves are distorted the rear park assist (RPA) module interprets this as an approaching object and will alert the driver by sounding a sequence of pulses or continuous tone from the warning buzzer.

### Reference Information

#### Schematic Reference

Object Detection Schematics.

#### Connector End View Reference

Component Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

### Circuit/System Testing

Important: Prior to performing circuit/system testing, ensure that the RPA module is receiving a satisfactory power/ground supply when reverse is selected. Refer to: Rear park assist inoperative.

Important: If one or more RPA sensors are suspected of being faulty perform the RPA sensor component test prior to performing circuit/system testing to identify the faulty sensor(s).

1. Ignition OFF, disconnect the parking sensor harness connectors.
2. Ignition ON, engine OFF, select reverse and test for (4.8 -- 5.2) volts between the 5-volt reference circuit terminal 2 and ground. Repeat for all sensors.

⇒ | If any value is less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If greater than the specified range, test the 5-volt reference circuit for a short to voltage.

3. Ignition OFF, disconnect the parking sensor harness connectors X2, X3, X4, X5 at the RPA module.

Test for less than 1.0 Ohm resistance between each low reference circuit listed below.

• | Right rear parking sensor terminal 1 and RPA connector X5 1.

• | Centre right rear parking sensor terminal 1 and RPA connector X4 1.

• | Centre left rear parking sensor terminal 1 and RPA connector X3 1.

• | Left rear parking sensor terminal 1 and RPA connector X2 1.

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

4. Test for infinite resistance to ground. Repeat for all circuits listed below:

• | Right rear parking sensor harness terminal 1

• | Centre right rear parking sensor harness terminal 1

• | Centre left rear parking sensor harness terminal 1

• | Left rear parking sensor harness terminal 1

⇒ | If not the specified value, repair/replace the parking sensor harness. If the circuits test normal, replace the RPA module.

### Component Testing

Important: When removing connectors inspect for damage or corrosion. Damage or corrosion in the following areas will require repair or replacement of the affected component/connector.

• | RPA sensors.

• | RPA module harness connectors.

• | RPA sensor harness connectors.

Complex objects may not be detected if the transmitted sound waves are reflected away from the objects rather than returning to the receiving parking sensor.

1. Ensure parking sensors are clean of road dirt.
2. Ensure parking sensors are not damaged.
3. Verify parking sensors are correctly installed.

⇒ | Refer to installation instructions.

4. Ignition OFF, disconnect harness connectors X3, X4, X5 at the RPA module.
5. Ignition ON, engine OFF, select reverse.
6. Place an RPA detectable object in front of the left rear parking sensor, the RPA warning buzzer should sound continuously. Move the object in small increments away from the left rear parking sensor. The warning buzzer should reduce its continuous sound to a decreasing pulsating sound as the object is moved further away from the left rear parking sensor.

⇒ | If the RPA system is not triggered by the left rear parking sensor, turn the ignition OFF and disconnect X2 at the RPA module and connect it to the X5 socket at the RPA module. Ignition ON, engine OFF, select reverse and repeat test step 6. If the RPA system does not respond disconnect the left rear parking sensor and substitute a known good parking sensor. If the RPA system still do not respond, replace the RPA module.

Important: Ensure that the ignition is turned OFF before the parking sensors are disconnected and ON when the test is performed.

7. Substitute the left rear parking sensor with the rest of the parking sensors one after the other and repeat test step 6 for each parking sensor. Replace any of the parking sensors if:

• | A parking sensor does not trigger the RPA system.

• | A parking sensor causes the system to sound continuously even after the object has been removed.

• | A parking sensor does not cause the RPA system to change to a pulsating sound.

• | A parking sensor appears to be too sensitive.

### Repair Instructions

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

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.