Park Assist System Chime/Buzzer - Operation

PARK ASSIST SYSTEM

The park assist system is active only when the ignition switch is in the RUN position, the transmission gear selector lever is in either the REVERSE position and the vehicle speed is less than 18 kph (12 mph). The park assist system is enabled from the factory as a default but can be manually disabled or enabled using the U-Connect Touch (TM) screen module, under the settings tab, by adding or removing a check mark in the OFF selection box, Integrated Center Stack Screen Module - Operation for more information.

The disable feature is provided for trailer towing purposes. With a trailer attached to the vehicle the audible and visible park assist alerts would be incessant whenever the gear selector lever was in the REVERSE 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 EVIC, a PARK ASSIST OFF textual message will appear within the EVIC display of the instrument cluster whenever the gear selector lever is in the REVERSE position.

The microprocessor based park assist 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 Instrument Cluster (IC), 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 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 park assist module, 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 visible to the vehicle operator only when looking forward and 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 park assist module 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 park assist module then sends an electronic message over the CAN data bus, and one of several SERVICE PARK ASSIST SYSTEM textual and graphical message is displayed within the EVIC display, when the message is received by the IC.

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, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.

However, conventional diagnostic methods will not prove conclusive in the diagnosis of the park assist system or the electronic controls or 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.