Park Assist System
The park assist system is active only when the status of the ignition switch is ON, the transmission gear selector is in either the Reverse R position and the vehicle speed is less than about 11 km/h (7 mph). The system can be manually disabled and enabled by the vehicle operator using the park assist OFF push button in the Integrated Center Stack (ICS). In vehicles equipped with this option, the system is enabled from the factory as a default.
The disable feature is provided for trailer towing purposes or for driver preference. With a trailer attached to the vehicle the audible and visible park assist alerts would be incessant whenever the transmission gear selector was in the Reverse (R ) position due to the proximity of the trailer to the rear of the vehicle. When the system is disabled, a park assist icon will appear within the display. On vehicles equipped with an optional Electronic Vehicle Information Center (EVIC), a PARK ASSIST OFF textual message will appear within the EVIC display of the instrument cluster whenever the transmission gear selector is in the Reverse R position.
The microcontroller-based Park Assist Module (PAM) (also known as the ParkTronic System/PTS module) is the central component of the park assist system. It supplies voltage to the park assist sensors, receives and analyzes data from the sensors, calculates and communicates the proper display information to the Instrument Panel Cluster (IPC), performs system diagnostics, and communicates with other electronic modules in the vehicle or with a diagnostic scan tool over the Controller Area Network (CAN) data bus. The module operates on battery voltage received through a fuse in the rear Power Distribution Center (PDC), and is grounded through a take out of the body wire harness.
Four ultrasonic park assist sensors in the rear bumper fascia allow the park assist system to locate and identify the proximity of nearby obstacles. These sensors each generate ultrasonic sound pulses when triggered by the PAM, then signal the module when an echo of the reflected sound pulses is received. The detection distance range from the rear of the vehicle is about 0.3 meters (11.8 inches) to about 2.0 meters (80 inches), and the detection height range from the ground is about 0.2 meters (7.8 inches) to about 0.8 meters (31 inches). The detection area extends somewhat around both rear sides (corners) of the vehicle.
The park assist display, located within the EVIC unit, provides the vehicle operator with a visible warning if the vehicle comes to within about 100 centimeters (39 inches) to 200 centimeters (79 inches) of the detected object. The display is active any time the vehicle is in Reverse (R ) and visible to the vehicle operator only when looking forward. When an object is detected within the detection zone, the system will also emit a series of short, intermittent, audible beeps and automatically lower the volume of the audio system 20 dB below a set tone alert volume, if the vehicles audio system is turned ON. The audible warning changes from intermittent beeps to a continuous tone as the vehicle comes to within 30 centimeters (12 inches) of a detected object.
When the PAM monitors a problem in any of the park assist system circuits or components, it stores a fault code or Diagnostic Trouble Code (DTC) in its memory circuit. The PAM then sends an electronic message over the CAN data bus, and one of several SERVICE PARK ASSIST SYSTEM textual and graphical messages is displayed within the EVIC display when the message is received by the IPC.
The hard wired circuits between components related to the park assist system may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds. For proper wire repair, and connector repair procedures. Refer to STANDARD PROCEDURE . and. Refer to REMOVAL . Refer to INSTALLATION .
However, conventional diagnostic methods will not prove conclusive in the diagnosis of the park assist system or the electronic controls and communication between modules and other devices that provide some features of the park assist system. The most reliable, efficient and accurate means to diagnose the park assist system or the electronic controls and communication related to park assist system operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.