GM Service Manual Online
For 1990-2009 cars only

Rear Park Assist Warning Buzzer Sounds Continuously Genuine Accessory

Diagnostic Fault Information

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

Circuit/System Description

The rear park assist system (RPA) is designed to assist the driver when reversing and should not be used as a substitute for safe driving practices. The RPA is equipped with a module, a warning buzzer and ultrasonic sensors. The ultrasonic sensors operate both as transmitters and receivers of ultrasonic signals. The driver is alerted to approaching objects by a sequence of pulses or continuous tones from the warning buzzer. The warning buzzer could sound continuously in the event of the following:

    • RPA sensor falsely obstructed.
    • RPA sensors faulty/disconnected at RPA module.
    • Warning buzzer harness faulty.

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

  1. Ensure parking sensors are clean of road dirt.
  2. Ensure parking sensors are not damaged.
  3. Verify parking sensors are correctly installed.
  4. Refer to installation instructions.
  5. Verify that the parking sensors are connected to the RPA module before turning the ignition ON and selecting reverse.
  6. If the parking sensors were disconnected, connect the parking sensors and reset the RPA module by selecting neutral and than reverse.
  7. Disconnect X1 at the RPA module. Verify that a test lamp does not illuminate between the circuits below and ground:
  8. • RPA connector X1-3.
    • RPA connector X1-4.
    If the test lamp illuminates, test the warning buzzer wiring for a short to voltage.

Repair Instructions

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

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.