Parking Assist System Malfunction (Accessory Dealer Installed)
Parking Assist System Malfunction (Accessory Dealer Installed)
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 Instructionsprovides 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 vehicles path when reversing. 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 a dedicated alarm module. The parking assist system becomes active when the vehicle is put into reverse.
Diagnostic Aids
The vehicle needs to be running and in reverse for the parking assist system to work.
The frequency of the normal audible tone is 750 Mhz. If the rear parking assist system detects a system concern, the audible tone will change to 2 Khz (higher pitch).
The following is a brief description of potential causes which may aid in diagnosis:
* 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 is missing, cut, or twisted.
* Improperly installed sensor, sensor may be crooked due to a tight wire harness.
* One or more of the sensors may be scratched or the paint is 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.
* An object is detected as being attached to the vehicle. Such as a hitch receiver, trailer, object hanging out of trunk, or bicycle rack.
* Damage to the rear of the vehicle. Inspect the bumper, bumper mounting surfaces, and sensor retainers.
* Outside frequency input to the sensor created by heavy pounding. Instances may be caused by a jackhammer or large changes in pressure, such as a large trucks air brakes.
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 (UVC) Object Detection (UVC)Object Detection Description and Operation (Accessory Dealer Installed) Object Detection Description and Operation (Accessory Dealer Installed)Object Detection Description and Operation (UD7) Object Detection (UD7)Object Detection Description and Operation (UFT) Object Detection (UFT)
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
Circuit/System Verification
Engine running, park brake on, transmission in reverse, verify that only one short beep (low pitch) sounds within 5 s to confirm that the object detection system is active.
If no audible tone is heard, refer to Object Alarm Module Circuit Malfunction.
If a continuous (low pitch) tone is present, refer to Object Alarm Module Circuit Malfunction.
If a continuous 5 s (high pitch) DTC tone is present, replace the K41 Front and Rear Parking Assist Control Module.
If one or more DTC beeps are present, check the appropriate rear object alarm sensor for contamination with mud, ice or snow. If no contamination is diagnosed, refer to Rear Object Alarm Sensor Circuit Malfunction.
Circuit/System Testing
Object Alarm Module Circuit Malfunction
1. Engine running, park brake applied, transmission in reverse, verify that the reverse lights illuminate.
• If the reverse lamps do not illuminate, refer to Backup Lamps Malfunction Backup Lamps Malfunction.
2. Ignition OFF, disconnect the X1 harness connector at the K41 Front and Rear Parking Assist Control Module.
3. Test for less than 10 ohm between the ground circuit terminal 7 and ground.
• If greater than the specified value, test the ground circuit for an open/high resistance.
4. Vehicle in park, verify that a test lamp does not illuminate between the control circuit terminal 1 and ground.
• If the test lamp does illuminate, test the control circuit for short to voltage.
5. Engine running, park brake applied, transmission in reverse, verify that a test lamp illuminates between the control circuit terminal 1 and ground.
• If the test lamp does not illuminate, test the control circuit for short to ground or an open/high resistance. If all circuits test normal refer to Backup Lamps Malfunction Backup Lamps Malfunction.
6. Ignition OFF, connect the X1 harness connector at the K41 Front and Rear Parking Assist Control Module.
7. Disconnect the harness connector at the P28 Speaker - Parking Assist.
8. Engine running, park brake applied, transmission in reverse, verify that a test lamp illuminates between the control circuit terminal 1 and ground.
• If the test lamp does not illuminate, test the control circuit for short to ground or an open/high resistance. If all circuits test normal, replace K41 Front and Rear Parking Assist Control Module.
9. Ignition OFF, connect test lamp between the control circuit terminal 1 and the control circuit terminal 2.
10. Engine running, park brake applied, while observing the test lamp, put the transmission in reverse. The test lamp should blink once as the transmission is put in reverse.
• If the test lamp is always on, test control circuit terminal 2 for short to ground. If the circuit tests normal, replace the K41 Front and Rear Parking Assist Control Module.
• If the test lamp is always off, test control circuit terminal 2 for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K41 Front and Rear Parking Assist Control Module.
11. If all the circuits test normal, test or replace the P28 Speaker - Parking Assist.
Rear Object Alarm Sensor Circuit Malfunction
1. Ignition OFF for 30 s, disconnect the harness connector at the appropriate rear object alarm sensor.
2. Test for less than 10 ohm between the low reference circuit terminal 2 and ground.
• If greater than the specified value, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K41 Front and Rear Parking Assist Control Module.
3. Engine running, park brake applied, transmission in reverse, test for 7.0-9. V between the 8 V reference circuit terminal 1 and ground.
• If less than 7.0 V, test the 8 V reference circuit for a short to ground, or an open/high resistance. If the circuit tests normal, replace the K41 Front and Rear Parking Assist Control Module.
• If greater than 9.0 V, test the 8 V reference circuit for a short to voltage. If the circuit tests normal, replace the K41 Front and Rear Parking Assist Control Module.
4. Ignition OFF, remove the malfunctioning rear object alarm sensor and swap locations with another properly functioning rear object alarm sensor. Connect the harness connector at both sensors.
5. Engine running, park brake applied, transmission in reverse verify the DTC tone is heard for the new location in which the malfunctioning sensor is installed.
• If the DTC tone is not heard for the new location, test the original location signal circuit terminal 3 for a short to voltage, short to ground, or an open/high resistance. If the circuit tests normal, replace the K41 Front and Rear Parking Assist Control Module.
6. If the DTC tone is heard for the new location in which the malfunctioning sensor is installed, replace the rear object alarm sensor.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
Note: For the dealer installed accessory parking assist system, the parking assist control module does not require any programming or setup.
* Rear Parking Assist Alarm Sensor Replacement Rear Parking Assist Alarm Sensor Replacement
* Rear Object Alarm Control Module Replacement Service and Repair
* Refer to Parking Assist Alarm Sensor Package Installation Instructions in the Accessory Installation Manual for Speaker - Parking Assist replacement.