For 1990-2009 cars

### Diagnostic Instructions

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

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

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category

### DTC Descriptors

DTC B0958 01: Park Assist Sensor Rear Left Outer Circuit Malfunction
DTC B0958 06: Park Assist Sensor Rear Left Outer Circuit Open or Low Voltage
DTC B0958 08: Park Assist Sensor Rear Left Outer Invalid Signal
DTC B0958 21: Park Assist Sensor Rear Left Outer Circuit Incorrect Period
DTC B0959 01: Park Assist Sensor Rear Left Middle Circuit Malfunction
DTC B0959 06: Park Assist Sensor Rear Left Middle Circuit Open or Low Voltage
DTC B0959 08: Park Assist Sensor Rear Left Outer Invalid Signal
DTC B0959 21: Park Assist Sensor Rear Left Outer Circuit Incorrect Period
DTC B0960 01: Park Assist Sensor Rear Right Middle Circuit Malfunction
DTC B0960 06: Park Assist Sensor Rear Right Middle Circuit Open or Low Voltage
DTC B0960 08: Park Assist Sensor Rear Right Middle Invalid Signal
DTC B0960 21: Park Assist Sensor Rear Right Middle Circuit Incorrect Period
DTC B0961 01: Park Assist Sensor Rear Right Outer Circuit Malfunction
DTC B0961 06: Park Assist Sensor Rear Right Outer Circuit Open or Low Voltage
DTC B0961 08: Park Assist Sensor Rear Right Middle Invalid Signal
DTC B0961 21: Park Assist Sensor Rear Right Middle Circuit Incorrect Period

### Circuit/System Description

The object detection system senses how close the vehicle is to an object. The distance is determined by the 4 ultrasonic sensors located in the rear bumper. The rear object detection system will notify the driver when approaching objects at speeds less than 15 km/h (9 mph), which makes parking easier and helps avoid collisions.

### Conditions for Running the DTC

Ignition voltage is between 9-16 volts.

### Conditions for Setting the DTC

#### B0958 01, B0959 01, B0960 01 or B0961 01

The rear object alarm module to rear object alarm sensor signal circuit is shorted to battery.

#### B0958 06, B0959 06, B0960 06 or B0961 06

The rear object alarm module to rear object alarm sensor signal circuit is shorted to ground or open/high resistance.

#### B0958 08, B0959 08, B0960 08 or B0961 08

The rear object alarm module to rear object alarm sensor signal is invalid.

#### B0958 21, B0959 21, B0960 21 or B0961 21

The rear object alarm module to rear object alarm sensor has an incorrect ring time.

### Action Taken When the DTC Sets

• | The rear object alarm module sets a DTC.

• | No confirmation tone will be heard when reverse gear is selected and hand brake is released.

### Reference Information

#### Schematic Reference

Object Detection Schematics

#### Connector End View Reference

Component Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References

### Circuit/System 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.

• | The rear object alarm sensor.

• | The rear object alarm module.

• | The rear object alarm sensor wiring harness connector.

• | The rear object alarm module wiring harness connector.

1. Ignition OFF, disconnect the wiring harness connector at the appropriate rear object alarm sensor.
2. Ignition ON, test for less than 1.0 ohm of resistance between the low reference circuit and a known ground.

⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the rear object alarm module.

3. Test for 8-9 volts between the 8.5 volt reference circuit and a known ground.

⇒ | If less than the specified range, test the 8.5 volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the rear object alarm module.

⇒ | If greater than the specified range, test the 8.5 volt reference circuit for a short to voltage. If the circuit tests normal, replace the rear object alarm module.

4. At the appropriate rear object alarm sensor, connect a 3-A fusible link wire between the signal circuit and the 8.5 volt reference circuit.
5. Ignition ON, at the rear object alarm module harness connector, measure for 8-9 volts between the signal circuit and a known ground.

⇒ | If 8.5 volts is present, replace the suspect rear object alarm sensor.

⇒ | If 8.5 volts is not present, test for short to ground or open/high resistance in the signal circuit.

6. If all circuits test normal, test or replace the appropriate rear object alarm sensor.

### Repair Instructions

• | Rear Object Sensor Replacement .

• | Control Module References .

### Repair Verification

1. Ignition ON, using a scan tool clear all DTCs.
2. After a repair for DTCs B0958 21, B0959 21, B0960 21 and B0961 21 has been completed, drive the vehicle for longer than 20 seconds and at a speed greater than 17km/h.
3. Ignition ON, using a scan tool Verify that no DTC are present.