Parking Aid - System Operation and Component Description: Notes
System Operation
Parking Aid
System Diagram
| Item | Description |
|---|---|
| 1 | PAM |
| 2 | RHF outer sensor |
| 3 | TCM |
| 4 | BCM |
| 5 | IPC |
| 6 | ACM |
| 7 | HS-CAN |
| 8 | PCM |
| 9 | ABS Module |
| 10 | MS-CAN |
| 11 | I-CAN |
| 12 | LHF outer sensor |
| 13 | RHF inner sensor |
| 14 | LHF inner sensor |
| 15 | RHR outer sensor |
| 16 | RHR inner sensor |
| 17 | LHR inner sensor |
| 18 | LHR outer sensor |
| 19 | park aid disable switch |
| 20 | with active park assist |
| 21 | with front park aid |
Network Message Chart
PAM Network Input Messages
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| Power mode | BCM | Used to command ignition position. |
| Parking aid enable status | IPC | Used to enable or disable the rear parking aid. |
| Reverse gear | PCM | Used to enable rear parking aid when the transmission is in REVERSE (manual transmission vehicles). |
| Selector lever (PRNDL) status | TCM | Used to enable rear parking aid when the transmission selector is in REVERSE (automatic transmission vehicles). |
| Vehicle speed | ABS | Used to disable the parking aid if the vehicle speed exceeds a preset threshold. |
ACM Network Input Messages
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| Tone request | PAM | Used to command audible parking aid tones through the front and/or rear speakers. |
Parking Aid System
When the front and/or rear audible parking aid system is active, the PAM calculates the distance to an object within a 170 degree semicircular area (azimuth) around the front or rear of the vehicle. A varible-frequency warning tone is generated through the audio speakers in proportion to the distance the object is from the front and/or rear of the vehicle.
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 183 cm (72in) from the rear of the vehicle, 30 cm (12in) 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, 20 cm (8 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.
Only objects that reflect a sufficient amount of sound waves are detected by the parking aid sensors. The surface properties, size and composition an object can affect the ability of the parking aid system to detect the object.
Also affecting the parking aid operation are:
- Improper sensor installation or alignment
- Dirt or ice covered sensors
- Heavy rain or snow
The parking aid system detects objects under the following conditions:
- The vehicle is in REVERSE (rear parking aid)
- The vehicle is in any gear except PARK or NEUTRAL (front parking aid)
- The vehicle is moving toward the object at 5 km/h (3 mph) or less
- The vehicle is stationary and the object is moving toward the vehicle at 5 km/h (3 mph) or less
- The vehicle and object are both moving toward one another and both are travelling at 5 km/h (3 mph) or less
Once vehicle speed reaches 12 km/h (7.5 mph) the parking aid system is disabled until the speed drops below 5 km/h (3 mph).
Parking Aid Audible Alert
The entertainment system volume is reduced when the park aid warning tone sounds. The frequency of the tones from the audio speakers increases as the vehicle moves closer to the object. When the object is within 305 mm (12 in) of the bumper, the tone becomes continuous. When the vehicle stops moving, the continuous tone stops after 3 seconds. Objects to the rear side generate a continuous tone for 3 seconds if the object is stationary or receding from the vehicle. The tone starts again if the object moves closer to the vehicle. The tone is prioritized to the system (front or rear) that has detected the closest object to the bumper. The tone alternates between front and rear audio speakers if an object is closer than 254 mm (10 in) front and rear.