The rear park assist module is supplied ignition voltage from the F20 10 A fuse. The system is turned on with ignition voltage supplied through the reverse lamp switch. The object detection sensors are supplied with signal circuits referenced from 8 volts by the module and low reference circuits. The alarm is supplied with an 8 volt power supply and low reference from the module. The alarm control circuit is an 8 volt circuit that is pulse width modulated low to activate the alarm.

The rear park assist system is capable of performing an object sensor self test. While in the sensor self test mode the rear park assist module will verify inputs from the object detection sensors. Refer to On-Board Diagnostic Features.

Schematic Reference

Object Detection Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Object Detection Description and Operation

Electrical Information Reference

1. Ignition ON, while the area behind the vehicle is clear of any objects which may activate the park assist alarm, shift the transmission to reverse. The park assist alarm should sound 1 short tone.

⇒	If not the specified value, refer to park assist system circuit test.

2. Perform the object detection sensor self test procedure in order to verify the sensor inputs to the module. Refer to On-Board Diagnostic Features.

⇒	If the self test mode indicates that any of the sensor inputs have failed, refer to object detection sensor circuit test.

Park Assist System Circuit Test

1. Ignition OFF, disconnect the harness connector at the park assist control module.
2. Test for less than 1.0 ohm between the ground circuit terminal 16 and ground.

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

3. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 8 and ground.

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

4. Transmission in reverse, verify that a test lamp illuminates between the backup lamp control circuit terminal 5 and ground.

⇒	If the test lamp does not illuminate, test the backup lamp control circuit for a short to ground or an open/high resistance. If circuit tests normal refer to Backup Lamps Inoperative.

5. Ignition OFF, connect the harness connector at the park assist control module.
6. Disconnect the harness connector at the park assist alarm.
7. Test for less than 1.0 ohm between the low reference circuit terminal 1 and ground.

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

8. Ignition ON, test for 7.5-8.2 V between the 8 V reference circuit terminal 3 and ground.

⇒	If less than the specified range, test the 8 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the park assist control module.

⇒	If greater than the specified range, test the 8 V reference circuit for a short to voltage. If the circuit tests normal, replace the park assist control module.

9. Ignition ON, test for 7.5-8.2 V between the alarm control circuit terminal 2 and ground.

⇒	If less than the specified range, test the alarm control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the park assist control module.

⇒	If greater than the specified range, test the alarm control circuit for a short to voltage. If the circuit tests normal, replace the park assist control module.

10. Connect a voltmeter between the alarm control circuit terminal 2 and ground.
11. Transmission in reverse, place an object less than 0.3 m (11 in) away from the rear bumper. The reading should respond by changing between the reference voltage and a lower value as the object is placed if front of the object detection sensors.

⇒	If the voltage reading does not respond, replace the park assist control module.

12. If all circuits test normal, replace the park assist alarm.

Object Detection Sensor Circuit Test

1. Ignition OFF, disconnect the harness connectors at the rear object detection sensors.
2. Test for less than 1.0 ohm between the low reference circuit terminals 2 and ground.

⇒	If greater than the specified value, test the appropriate low reference circuit for an open/high resistance.

3. Test for 7.5-8.2 V between the rear object detection sensors signal circuit terminals 1 and ground.

⇒	If less than the specified range, test the appropriate signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the park assist control module.

⇒	If greater than the specified range, test the appropriate signal circuit for a short to voltage. If the circuit tests normal, replace the park assist control module.

4. If all circuits test normal, replace the appropriate object detection sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.