Parking Assist System Malfunction
Parking Assist System Malfunction
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
Diagnostic Fault Information
Circuit/System Description
The ultrasonic parking assist system is designed to identify and notify the driver of an object in the vehicle's path when moving forward or reversing at speeds of less than 8 km/h (5 MPH). The distance and location of the object is determined by four object sensors: located in the rear bumper. The parking assist system will notify the driver using an audible signal through the radio.
Diagnostic Aids
The following is a brief description of potential causes which may aid in diagnosis:
* Hitch/Object Attached-The parking assist control module is detecting an object that is attached to the vehicle. Common items such as a hitch receiver, trailer, or a bicycle rack may cause this concern. Additionally, damage to the rear of the vehicle or a misaligned sensor may cause this concern. If the vehicle is damaged in a manner that causes the sensor to detect the bumper itself, the parking assist control module will interpret this as an attached object and disable the system. Carefully inspect the bumper, bumper mounting surface, and sensor retainers before continuing with normal diagnosis. After the detected cause has been addressed the vehicle must be driven at speed greater than 40 km/h (25 MPH).
* Vehicle Overspeed-The vehicle is travelling too fast in reverse at speeds of greater than 8 km/h (5 MPH).
* Inhibit-The parking assist control module has lost or received invalid GMLAN signal(s).
* Sensor Disturbance-An outside interference is causing sensor movement. Such interference may be caused a heavy pounding, like that of a nearby jackhammer, or large changes in pressure, such as a large truck's air brakes.
* Sensor Ring Time-If the sensor fails its own diagnostic initialization the parking assist control module will set this error. After the detected cause has been addressed the vehicle must be driven at speed greater than 40 km/h(25 MPH). The following is a list of reasons this cause may have set:
- One or more of the sensors may be blocked by snow, mud, ice, or other debris. This might happen after going through a car wash in cold weather.
- Silicone insulator surrounding sensor maybe missing, cut, or twisted.
- Improperly installed sensor, sensor maybe be crooked due to a tight wire harness.
- One or more of the sensors may be scratched or the paint maybe chipped.
- Excessive paint thickness on a sensor may cause an excessive sensor ring time. When replacing or refinishing a sensor, do not apply an excessive amount of paint or clear coat.
Reference Information
Schematic Reference
Object Detection Schematics [1][2]Collision Avoidance and Parking Assist Systems
Connector End View Reference
Component Connector End Views Outside Rearview Mirror - Driver
Description and Operation
Object Detection Description and Operation Description and Operation
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Control Module References
Circuit/System Verification
1. Observe the scan tool Park Assist parameter while putting the gear in reverse. The parameter should change between Active and Inactive.
• If the parameter does not change between the specified values, refer to Parking Assist Circuit Malfunction.
2. For vehicles with manual transmission: Transmission in reverse, verify the Engine Control Module (ECM) scan tool Reverse Position Switch parameter is Active.
• If not the specified value, refer to Backup Lamps Malfunction Backup Lamps Malfunction.
Note: After completing the next step the vehicle might need to be driven in the forward direction at speed greater than 40 km/h (25 MPH).
3. Transmission in REVERSE, verify the scan tool Park Assist System Status parameter displays Enable.
• If not the specified value, refer to Diagnostic Aids to determine the cause of the inhibit.
Circuit/System Testing
1. Ignition OFF, remove the ignition key, open the driver door and disconnect the scan tool.
2. Disconnect the X1 harness connector at the K41R Rear Parking Assist Control Module.
3. Test for less than 5 ohms between the grouond circuit terminal 7 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
4. Verify that the test lamp illuminates between the B+ circuit terminal 1 X1 at the K41R Rear Parking Assist Control Module and ground.
• If the test lamp does not illuminate, test the control circuit for an open/high resistance. If all circuits test normal, replace the K41R Rear Parking Assist Control Module.
5. If all circuits test normal, replace the K41R Rear Parking Assist Control Module.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Accessory Switch Replacement Service and Repair
* Control Module References Control Module References for parking assist control module replacement, programming and setup.