For 1990-2009 cars

### Diagnostic Instructions

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

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Parallel Parking Assist Switch Signal | B096B 02 | 1 | 1 | --
Parallel Parking Assist Switch Ground | -- | 1 | -- | --
1. Parallel Parking Assist Switch Malfunction

### Circuit/System Description

The parallel parking assist system is able to guide the driver into a parking lot by giving instructions. The system consists of the 8 parking assist sensors from the normal parking assist located in the front and rear bumper, and two additional parallel parking assist sensors on the side of the vehicle. The additional parallel parking assist sensors are used to measure the parking lot size. The parallel parking assist system uses the 8 parking assist sensors to identify objects in the vehicle's path when moving into the parking lot.

The parallel parking assist is activated / deactivated by pressing the parallel parking assist switch. The activated parallel parking assist searches for an appropriate parking lot. If a lot is detected, feedback is given to the driver through the indicator in the driver information center. The driver accepts the decision by stopping the vehicle. The system calculates the optimal path into the parking lot and guides the driver into the lot by giving instructions.

### 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 the diagnosis:

• | Manual Disable - The parallel parking assist system has been disabled by the vehicle operator through the parallel parking assist switch.

• | Hitch / Object Attached - The object alarm 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 object alarm 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.

• | Vehicle Overspeed - The vehicle is travelling too fast at speeds of greater than 8 km/h (5 MPH).

• | 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.

• | Snow / Ice / Mud - One or more of the sensors is being blocked by snow, mud, ice or other debris.

• | Sensor Ring Time - Each of the sensors emits an ultrasonic frequency. This frequency is reflected off of nearby objects, bouncing it back towards the vehicle bumper where it is received by the sensor. The time between the sensor emitting the frequency and the sensor receiving the reflection, known as sensor ring time, is used to determine the distance of nearby objects. 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

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Object Detection Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

1. Verify the correct function of the parking assist system.

⇒ | If the parking assist system malfunctions, refer to Parking Assist System Malfunction

2. Ignition ON, observe the scan tool Advanced Park Assist Switch parameter while pressing and releasing the parallel parking assist switch. The parameter should change between Active and Inactive.

⇒ | If the parameter does not change between the specified values, refer to Circuit/System Testing.

3. Observe the Body Control Module (BCM) Brake Switch parameter while pressing and releasing the brake pedal. The parameter should change between Active and Inactive.

⇒ | If the parameter does not change between the specified values, refer to Stop Lamps Malfunction.

4. Vehicle in reverse, verify the Engine Control Module (ECM) scan tool Reverse Switch parameter is Active.

⇒ | If not the specified value, refer to Backup Lamps Malfunction

5. Press the parallel parking assist switch, verify the scan tool Park Assist System Status parameter is Enable.

⇒ | 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.

6. If all tests normal, replace the K41 Object Alarm Module.

### Circuit/System Testing

1. Ignition OFF, disconnect the X2 and X3 harness connectors at the K41 Object Alarm Module and the X1 harness connector at the S48D Multifunction Switch - I/P 2.
2. Test for less than 5 Ω between the S48D Multifunction Switch - I/P 2 ground circuit terminal 2 (X1) and ground.

⇒ | If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, test for less than 0.3 V between the signal circuit terminal 6 (X1) at the K41 Object Alarm Module harness connector and ground.

⇒ | If greater than the specified range, test the signal circuit for a short to voltage.

4. Ignition OFF, connect the harness connector at the S48D Multifunction Switch - I/P 2.
5. Ignition ON, verify that a test lamp does not illuminate between the B+ circuit terminal 2 (X3) at the K41 Object Alarm Module harness connector and signal circuit terminal 6 (X1).

⇒ | If the test lamp illuminates, test signal circuit for a short to ground. If the circuit tests normal, replace the S48D Multifunction Switch - I/P 2.

6. Verify that the test lamp illuminates between the B+ circuit terminal 2 (X3) at the K41 Object Alarm Module harness connector and signal circuit terminal 6 (X1) while pressing the parallel 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 S48D Multifunction Switch - I/P 2.

7. If all circuits test normal, replace the K41 Object Alarm Module.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Rear Object Alarm Module Switch Replacement

• | Control Module References for object alarm module replacement, setup and programming