The object alarm module directly controls the rear parking assist (RPA) display. The RPA display consists of 2 amber and one red LED that indicate the distance of an object from the rear bumper. The object alarm module will also use an audible warning by sending a serial data message to the radio. Each object sensor is a 3-wire sensor that is both a transmitter and a receiver that includes a signal circuit, a low reference circuit, and an 8-volt supply voltage circuit. The object alarm module supplies 8 volts to the object sensors via the object sensor supply voltage circuit and provides ground via the low reference circuit. The object alarm module triggers the sensors in a sequential loop and after each sensor transmits, the object alarm module uses the echo or signal return to calculate the distance and position of an object from the rear bumper.

Schematic Reference

Object Detection Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Object Detection Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, observe the scan tool Sensor Feed Voltage Output parameter. The reading should be between 8.0-9.0 volts.
2. Perform the LED Test, using the scan tool. Observe the operation of the three LEDs. All three LEDs should illuminate.

1. Ignition OFF, disconnect the harness connector at the RPA display.
2. Ignition ON, verify that a test lamp illuminates between the 12 volt voltage supply circuit terminal A and ground.

⇒	If the test lamp does not illuminate, test the voltage supply circuit terminal for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the object alarm module.

3. Connect a test lamp between the 12 volt supply circuit terminal A and the appropriate LED listed below:

•	Left amber LED control circuit terminal B

•	Center amber LED control circuit terminal C

•	Red LED control circuit terminal D

4. Command the appropriate LED ON and OFF with a scan tool, verify that a test lamp turns ON and OFF when switching between commanded states.

⇒	If the test lamp does not illuminate, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, test or replace the object alarm module.

⇒	If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, test or replace the object alarm module.

5. If all circuits test normal, test or replace the RPA display.

1. Ignition OFF, disconnect the harness connector at the RPA display.
2. Connect a 10A fused jumper wire between the 12 volt supply circuit terminal A and B+.
3. Connect a 10A fused jumper wire between the control circuit terminals listed below and ground:

•	Left amber LED control circuit terminal B

•	Center amber LED control circuit terminal C

•	Red LED control circuit terminal D

4. Verify that the appropriate LED illuminates.

⇒	If the component does not perform as specified, replace the RPA display.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.