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.

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 reverse at speeds of less than 8 km/h (5 MPH). The distance and location of the object is determined by 4 object sensors, located in the rear bumper. The parking assist system will notify the driver using an audible signal through the radio.

Diagnostic Aids

For Symptom Byte 21 the module only run diagnostic when the vehicle is driven greater than 40 km/h (25 MPH). Therefore, even with clean sensor with no obstruction (i.e. snow or ice melted off) drive the vehicle greater than 40 km/h (25 MPH).

The following is a list of reasons this failure type byte 21 might 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 Sunshade - Left Front

Description and Operation

Object Detection Description and Operation (UD7) Object Detection (UD7)Object Detection Description and Operation (Front View Camera with UEU) Object Detection Description and Operation (Front View Camera with UEU)Object Detection Description and Operation (Front View Camera with UFL) Object Detection Description and Operation (Front View Camera with UFL)Object Detection Description and Operation (UVC) Object Detection (UVC)

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 for scan tool information.

Circuit/System Verification

1. Ignition ON.

2. Verify the park assist system is enabled through the parking assist switch.

• If the park assist system is manually disabled, enable the system.
Refer to the vehicle owners manual for instructions on enabling the system.

• If the park assist system does not manually change

3. Verify 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 Active and Inactive
Refer to Parking Assist Switch Circuit Malfunction.

• If the parameter changes between Active and Inactive

4. 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.

• If the indicator does turn ON and OFF

5. Transmission in reverse, verify the Engine Control Module (ECM) scan tool Reverse Position Switch parameter is Active.

• If the parameter is not Active
Refer to Backup Lamps Malfunction Backup Lamps Malfunction.

• If the parameter is Active

6. Transmission in REVERSE, verify the scan tool Park Assist System Status parameter displays Enable.

• If the parameter is not Enabled
Refer to Diagnostic Aids to determine the cause of the inhibit.

• If the parameter is Enabled

7. All OK.

Circuit/System Testing

Parking Assist Switch Circuit Malfunction

1. Ignition OFF, disconnect the harness connector at the S48D Multifunction Switch 2 - Instrument Panel.

2. Test for less than 10 ohms between the ground circuit terminal 1 and ground.

• If 10 ohms or greater

1. Ignition OFF.

2. Test for less than 2 ohms in the ground circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, repair the open/high resistance in the ground connection.

• If less than 10 ohms

3. Ignition ON.

4. Verify the scan tool Parking Assist Switch Status parameter is inactive.

• If not Inactive

1. Ignition OFF, disconnect the harness connector at the K41R Rear Parking Assist Control Module.

2. Test for infinite resistance between the control circuit terminal 5 and ground.

• If less than infinite resistance, repair the short to ground on the circuit.

• If infinite resistance, replace the K41R Rear Parking Assist Control Module.

• If Inactive

5. Test for less than 1 V between the control circuit terminal 5 and ground.

• If 1 V or greater
Repair the short to voltage on the circuit.

• If less than 1 V

6. Connect a test lamp between the control circuit terminal 5 and the ground circuit terminal 1.

7. Verify that a test lamp turns On and Off when Commanding the Parking Assist Switch On and Off with a scan tool.

• If the test lamp is always OFF

1. Ignition OFF, disconnect the harness connector at the K41R Rear Parking Assist Control Module

2. Test for infinite resistance between the control circuit and ground.

• If less than infinite resistance, repair the short to ground in the circuit.

• If infinite resistance

3. Test for less than 2 ohms in the control circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, replace the K41R Rear Parking Assist Control Module.

• If the test lamp is always ON

1. Ignition OFF, disconnect the harness connector at the K41R Rear Parking Assist Control Module, ignition ON.

2. Test for less than 1 V between the control circuit and ground.

• If 1 V or greater, repair the short to voltage on the circuit.

• If less than 1 V, replace the K41R Rear Parking Assist Control Module

• If the test lamp turns ON and OFF

8. All OK.

Parking Assist Switch Indicator Circuit Malfunction

1. Ignition OFF, disconnect the harness connector at the S48D Multifunction Switch 2 - Instrument Panel, Ignition ON.

2. Test for greater than 11 V between the terminal 3 and ground.

• If less than 11 V
Test the voltage circuit for a short to ground or an open/high resistance.

• If greater than 11 V

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 and the signal circuit terminal 5.

• If less than 11 V
Test the signal circuit for an open/high resistance.

• If greater than 11 V

4. Command the Park Assist Switch Indicator Off with the scan tool.

5. Test for less than 1 V between the terminal 6 and ground.

• If 1 V or greater
Test the signal circuit for a short to voltage.

6. If all circuits test normal, replace the S48D Multifunction Switch 2 - Instrument Panel.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

* Control Module References Control Module References for parking assist control module replacement, programming, and setup