Parking Aid - System Operation and Component Description: Notes
System Operation
Parking Aid - Audible
System Diagram
Network Message Chart PAM Network Input Messages
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| Ambient air temperature filtered | PCM | Used to temperature compensate the parking aid sensors. |
| Day/night status | BCM | Light compensates the parking aid sensors. |
| Gear lever position | PCM | Enables or disables the front or rear parking aid depending on the gear lever position. |
| Front parking aid enable request | IPC | Enables or disables the front parking aid. |
| Ignition key type | BCM | Disables the parking aid switch when a MyKey® restricted key is in use. |
| Ignition status | BCM | Communicates the ignition switch state. |
| Outside air temperature | HVAC module | Temperature compensates the parking aid sensors. |
| Rear parking aid enable request | IPC | Enables or disables the rear parking aid. |
| Stability-traction control event in progress | ABS module | Disables the active park assist if a stability or traction control system activation occurs. |
| Stability-traction control indicator request | ABS module | Disables the active park assist if a stability or traction control system fault occurs. |
| Steering wheel angle | ABS module | Determines the current steering angle. |
| Trailer lamp connected | TRM | Deactivates the system if a trailer is connected. |
| Vehicle configuration data | BCM | Determines the vehicle configuration. |
| Vehicle speed | PCM | Disables the parking aid if the vehicle speed exceeds a preset threshold. |
| Wheel speed data | ABS module | Confirms vehicle movement and calculates distance traveled during active park assist maneuvers. |
| Wheel rotation data | ABS module | Confirms wheel rotation during active park assist maneuvers. |
| Wheel rotation direction | ABS module | Confirms wheel rotation direction during active park assist maneuvers. |
IPC Network Input Messages
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| Audio chime status | ACM | Provides audio chime status feedback to the IPC. |
| Parking aid chime request | PAM | Commands parking aid warning tones through the IPC chime arbitrator. |
| Parking aid fault status | PAM | Indicates a parking aid fault. |
| Parking aid front status | PAM | Indicates the status of the front parking aid. |
| Parking aid rear status | PAM | Indicates the status of the rear parking aid. |
| Parking aid sensor data | PAM | Provides data on the parking aid sensors. |
| Parking aid text message | PAM | Provides parking aid information for the message center. |
APIM network Input Messages
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| Parking aid chime request | PAM | Commands parking aid warning tones through the IPC chime arbitrator. |
| Parking aid fault status | PAM | Indicates a parking aid fault. |
| Parking aid front status | PAM | Indicates the status of the front parking aid. |
| Parking aid rear status | PAM | Indicates the status of the rear parking aid. |
| Parking aid sensor data | PAM | Provides data on the parking aid sensors. |
| Parking aid text message | PAM | Provides parking aid information for the message center. |
ACM Network Input Messages
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| IPC chime request | IPC | The request to turn on the parking aid chime comes in this message. |
DSP Network Input Messages
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| IPC chime request | IPC | The request to turn on the parking aid chime comes in this message. |
Audible Parking Aid System Operation
The rear parking aid system calculates the distance to an object around the rear of the vehicle using 4 ultrasonic sensors. The rear parking aid sensors detect objects approximately 180 cm (70 in) from the rear of the vehicle, 50 cm (20 in) from the rear side of the vehicle, and 30 cm (12 in) above the ground. To detect objects behind the vehicle, the PAM supplies voltage and ground to the rear ultrasonic sensors while monitoring a signal return circuit from each sensor. The 4 rear sensors share common voltage and ground circuits.
The front parking aid system calculates the distance to an object around the front of the vehicle using 4 ultrasonic sensors. The front parking aid sensors detect objects approximately 70 cm (27 in) from the front of the vehicle, 50 cm (20 in) from the front side of the vehicle, 30 cm (12 in) above the ground. To detect objects in front of the vehicle, the PAM supplies voltage and ground to the front ultrasonic sensors while monitoring a signal return circuit from each sensor. The 4 front sensors share common voltage and ground circuits. Vehicles equipped with active park assist must be equipped with the front parking aid system.
Only objects that reflect a sufficient amount of sound waves are detected by the parking aid sensors. The surface properties, size and composition of an object can affect the ability of the parking aid system to detect the object.
Parking aid operation may be affected by:
- Improper sensor installation or alignment
- Dirt or ice covered sensors
- Heavy rain or snow
The parking aid system detects objects when the vehicle is in any of the following conditions:
- REVERSE (rear parking aid).
- Motion in any gear except NEUTRAL (front parking aid and side sensing system, if equipped).
- Moving toward the object.
- Stationary and the object is moving toward the vehicle.
- The vehicle and object are both moving toward one another.
The following may trigger false detections when driving at slow/creeping speeds (could be decelerating or accelerating) less than 12 km/h (8 mph), but not at a stop:
- Near another vehicle equipped with parking aid sensors. The other vehicle could be several meters away (it does not have to be within the detection zone of the host vehicle).
- Near a semi truck or school bus with air brakes (while the bus/truck is applying their brake).
- Near another signal with the same frequency.
As the distance to the obstacle decreases, the indicator blocks illuminate and move toward the vehicle icon as displayed on the audio system display. If there is no obstacle detected, the distance indicator blocks are greyed out.
Side Sensing (If Equipped with Active Park Assist)
The side sensing system calculates the distance to an object around the sides of the vehicle using the four active parking aid sensors used for the active park assist. The side sensors detect objects approximately 60 cm (24 in) from the side of the vehicle. A chime sounds when an object is approximately 30 cm (12 in) from the side of the vehicle. To detect objects on the sides of the vehicle, the PAM supplies voltage and ground to the front ultrasonic sensors while monitoring a signal return circuit from each sensor. The 2 front side sensors share common voltage and ground circuits with the front parking aid sensors. The 2 rear side sensors share common voltage and ground circuits with the rear parking aid sensors.
Parking Aid Audible Alert
Audio system volume is automatically reduced when a parking aid alert tone is sounded. The alert tone frequency increases as the vehicle gets closer to an obstacle. When an object is detected within 30 cm (12 in) of the sensors, the warning tone becomes continuous. When the vehicle stops moving the continuous tone stops after 3 seconds until the vehicle moves again. Objects detected outside the continuous tone area to the side of the vehicle generate a warning tone for 3 seconds. The warning tones are prioritized to the closest object. If the front and rear objects are located the same distance from the vehicle, the rear object is prioritized.