• | 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. |
The object alarm 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 object detection system will notify the driver when backing up at speeds less than 8 km/h (5 mph), which make parking easier and helps you avoid colliding with objects such as parked vehicles.
Each object sensor is a 3-wire sensor that is both a transmitter and a receiver that comprises a signal circuit, a low reference circuit, and an 8-volt supply voltage circuit. The rear object control module supplies 8 volts to the object sensors via the object sensor supply voltage circuit and provides ground via the low reference circuit. The rear object control module triggers the sensors in a sequential loop and after each sensor transmits, the rear object control module uses the echo or signal return to calculate the distance and position of an object from the rear bumper. The rear object control module directly controls the rear parking assist (RPA) display. The RPA consists of 2 amber and one red LED that indicate the range of an object from the rear bumper. The rear object control module will also use an audible warning by sending a low speed GMLAN message to the radio.
Ignition voltage is between 9-16 volts.
The following condition must exist for 300 milliseconds:
The object alarm module has detected that one of the three indicator control circuits for the rear display is determined to be open or shorted.
• | The object alarm module commands ON the telltale assembly information center red indicator and disables the object detection system. |
• | The object alarm module will send a serial data message to the instrument panel cluster (IPC) to display SERVICE PARK ASSIST message in the driver information center (DIC) and a chime will sound from the radio speakers. |
Object Detection Connector End Views
Object Detection Description and Operation
The red indicator displays continuously in the rear or front telltale assembly information center. If red indicator is not flashing, check if DTC is history.
⇒ | If the test lamp does not illuminate, test the supply voltage circuit for a short to ground or an open/high resistance. |
⇒ | If the test lamp does not illuminate for one or more indicator control circuits, test the suspect indicator control circuit for a short to ground or an open/high resistance. If all the circuit(s) test normal, replace the telltale assembly information center. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for object alarm module replacement, setup, and programming