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 path when 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 scan tool Park Assist Disable History parameters are a list of the seven previous reasons the parking assist system was disabled. These parameters may help in the diagnosis of an intermittent concern or a customer concern which is the result of normal system operation. The following is a brief description of potential causes which may aid in diagnosis:
* Manual Disable - The parking assist system has been disabled through the parking assist switch or audio system personalization menu.
* 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).
* Reverse 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 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.
- Extreme paint thickness on a sensor may cause an extreme sensor ring time. When replacing or refinishing a sensor, do not apply an extreme 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 (Connector End Views By Name)
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 (Programming and Relearning)for scan tool information
Circuit/System Verification
1. Ignition ON, verify the park assist system is enabled through the parking assist switch.
• If the park assist system is manually disabled, enable the system.
2. Observe the scan tool Park Assist Switch parameter while pressing and releasing the parking assist switch. The parameter should change between Active and Inactive.
• If the parameter does not change between the specified values, refer to Parking Assist Switch Circuit Malfunction.
3. Command the Park Assist Switch LED output control ON and OFF with the scan tool. The parking assist switch indicator should turn ON and OFF when changing between the commanded states.
• If the indicator does not turn ON and OFF, refer to Parking Assist Switch Indicator Circuit Malfunction.
4. Transmission in REVERSE, verify the scan tool Park Assist System Status parameter is Enable.
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).
• If not the specified value, refer to Diagnostic Aids and the scan tool Park Assist Disable History parameters to determine the cause of the inhibit.
Circuit/System Testing
Parking Assist Switch Circuit Malfunction
1. Ignition OFF, disconnect the X1 harness connector at the K41 Parking Assist Control Module and the X1 harness connector at the S48E Multifunction Switch Module - Center Console.
2. Test for less than 5 ohm between the S48E Multifunction Switch Module - Center Console ground circuit terminal 2 X1 and ground.
• If greater than the specified value, test the ground circuit for an open/high resistance.
3. Ignition ON, test for less than 0.3 V between the signal circuit terminal 8 X1 at the K41 Parking Assist Control Module harness connector and ground.
• If greater than the specified value, test the signal circuit for a short to voltage.
4. Ignition OFF, connect the harness connector at the S48E Multifunction Switch Module - Center Console.
5. Ignition ON, verify that a test lamp does not illuminate between the B+ circuit terminal 1 X1 at the K41 Parking Assist Control Module harness connector and signal circuit terminal 8 X1.
• If the test lamp illuminates, test signal circuit for a short to ground. If the circuit tests normal, replace the S48E Multifunction Switch Module - Center Console.
6. Verify that the test lamp illuminates between the B+ circuit terminal 1 X1 at the K41 Parking Assist Control Module harness connector and signal circuit terminal 8 X1 while pressing the parking assist switch.
• If the test lamp does not illuminate, test the signal circuit for an open/high resistance. If all circuits test normal, replace the S48E Multifunction Switch Module - Center Console.
7. If all circuits test normal, replace the K41 Parking Assist Control Module.
Parking Assist Switch Indicator Circuit Malfunction
1. Ignition OFF, the X1 harness connector at the S48E Multifunction Switch Module - Center Console.
2. Ignition ON, test for greater than 11 V between the ignition circuit terminal 3 X1 and ground.
• If less than the specified value, test the ignition circuit for a short to ground or an open/high resistance.
3. Command the Park Assist Switch LED output control ON with the scan tool. Test for greater than 11 V between the ignition circuit terminal 3 X1 and the signal circuit terminal 6 X1.
• If less than the specified value, test the signal circuit for an open/high resistance. If all circuits test normal, replace the K41 Parking Assist Control Module.
4. Command the Park Assist Switch LED output control OFF with the scan tool. Test for less than 0.3 V between the ignition circuit terminal 3 X1 and the signal circuit terminal 6 X1.
• If greater than the specified value, test the signal circuit for a short to ground. If all circuits test normal, replace the K41 Parking Assist Control Module.
5. If all circuits test normal, replace the S48E Multifunction Switch Module - Center Console.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
Control Module References (Programming and Relearning)for parking assist control module replacement, setup and programming