Scheme 1
A chime warning system is standard factory-installed equipment. The chime warning system uses an electromechanical transducer attached to the electronic circuit board inside of the instrument cluster (1) to provide audible indications of various vehicle conditions that may require the attention of the vehicle operator or occupants. The instrument cluster also includes the hardware and software necessary to serve as the electronic body control module and is sometimes referred to as the Cab Compartment Node (CCN).
The electromechanical transducer generates beep tones, chime tones and click tones to emulate the sounds associated with conventional turn signal and hazard warning flasher operation. The microprocessor-based instrument cluster utilizes electronic chime request messages received from other modules in the vehicle over the Controller Area Network (CAN) data bus along with hardwired inputs to monitor many sensors and switches throughout the vehicle. In response to those inputs, the circuitry and programming of the CCN allow it to control the audible outputs that are produced through its on-board transducer.
The CCN is capable of producing the following audible outputs
- Slow Rate Repetitive Click - Repeated click tones that are issued at a slow rate of about 50 clicks per minute.
- Fast Rate Repetitive Click - Repeated click tones that are issued at a fast rate of more than about 100 clicks per minute.
- Fixed Duration Beep - A short, sharp, single tactile beep tone.
- Single Chime Tone - A single chime tone.
- Slow Rate Repetitive Chime - Repeated chime tones that are issued at a slow rate of about 50 chimes per minute.
- Fast Rate Repetitive Chime - Repeated chime tones that are issued at a fast rate of about 180 chimes per minute.
Hardwired circuitry connects the CCN and the various chime warning system switch and sensor inputs to their modules and to each other through the electrical system of the vehicle. These hard wired circuits are integral to several wire harnesses, which are routed throughout the vehicle and retained by many different methods. These circuits may be connected to each other, to the vehicle electrical system and to the CCN through the use of a combination of soldered splices, splice block connectors, and many different types of wire harness terminal connectors and insulators. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, further details on wire harness routing and retention, as well as pin-out and location views for the various wire harness connectors, splices and grounds.
The instrument cluster chime warning system circuits and components cannot be adjusted or repaired. If the CCN circuitry or the on-board transducer are damaged or inoperative, the complete unit must be replaced.
Scheme 2
A park assist system is an optional factory-installed electronic parking aid. During parking and other similar vehicle maneuvers this system alerts the vehicle operator to obstacles located in the path immediately behind the vehicle which, due to the surrounding rear vehicle structure, might be otherwise difficult to perceive. When an object is detected, the system displays a textual message within the Electronic Vehicle Information Center (EVIC) display unit to provide the vehicle operator with visual and audible indications of the presence and proximity of such objects.
The park assist system includes the following major components, which are described in further detail elsewhere in this service information
- Electronic Vehicle Information Center (1) - In vehicles equipped with the optional park assist system, the optional EVIC in the instrument cluster displays textual warnings and error messages, and emits audible warnings related to the current operating status of the park assist system. The display also provides an interface that allows the vehicle operator to manually disable or enable the system using the customer programmable features option.
- Park Assist Module (2) - Vehicles equipped with the park assist system include a park assist module which is secured to a mounting bracket by two fasteners and is concealed above the headliner.
- Park Assist Sensors (3) - Vehicles equipped with the park assist system have four ultrasonic park assist sensors that are concealed behind the rear bumper. Each sensor is snapped into an individual molded plastic mounting bracket located at horizontal intervals along the back side of the rear bumper.
Hardwired circuitry connects the various park assist system components to each other through the electrical system of the vehicle. These hardwired circuits are integral to several wire harnesses, which are routed throughout the vehicle and retained by many different methods. These circuits may be connected to each other and to the vehicle electrical system through the use of a combination of soldered splices, splice block connectors, and many different types of wire harness terminal connectors and insulators. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, further details on wire harness routing and retention, as well as pin-out and location views for the various wire harness connectors, splices and grounds.
The park assist system components cannot be adjusted or repaired. If any of the park assist system components is damaged or ineffective, that component must be replaced.
DESCRIPTION
The Park Assist display is an integral part of the Electronic Vehicle Information Center (EVIC). The park assist ICON , for image information, is only displayed when an object is detected. Refer to International Vehicle Control and Display Symbols , Description . An electronic message is sent to the Cab Compartment Node (CCN) from the park assist module, over the Controller Area Network (CAN) Data Bus when an object is within the detection area. The CCN then displays the object detection icon with the corresponding alert bar for the distance and location of the object within the EVIC display.
Depending on market and system capabilities, the display icon has as many as 24 different variations with the corresponding alert bars, depending on size, location and distance of the object being detected. The image will display three solid bars followed by a single tone for maximum distance then will flash and reduce the amount of bars as the proximity to the object is reduced followed by a repetitive tone, down to a single bar with a continuous tone.
The EVIC display is only serviced as a complete unit with the instrument cluster. It cannot be adjusted or repaired. If ineffective or damaged, the entire display unit must be replaced. For more information, refer to CENTER, Electronic Vehicle Information , Description.
OPERATION
The Park Assist system for this vehicle is only available on vehicles equipped with an Electronic Vehicle Information Center (EVIC). The park assist display is an integrated part of the EVIC and receives battery current and ground from, and is completely controlled by, the Cab Compartment Node (CCN). The CCN will display the park assist ICON whenever an object is detected and a signal is received from the park assist module, over the Controller Area Network (CAN) data bus. The icon image displayed has as many as 24 different variations depending on size, distance and location of the object being detected. The microprocessor in the park assist module continually monitors the display status, and will store a Diagnostic Trouble Code (DTC) in memory for any monitored fault it detects in the park assist display.
The hard-wired circuits between components related to the park assist display 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 display 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 display or the electronic controls and communication related to park assist display operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.
Scheme 3
The Park Assist Module (1) is secured to a mounting bracket (2) that is bonded to the upper side of the vehicles headliner (3) above the right sun visor and secured by two fasteners (4). Concealed within the molded plastic park assist module housing is a microprocessor and the other electronic circuitry of the module. The module housing is sealed to enclose and protect the internal electronic circuitry. The module software is flash programmable.
Two connector receptacles (5) containing terminal pins are integral to the forward-facing side of the housing. The module is connected to the vehicle electrical system through two dedicated take outs and connectors of the body wire harness.
The park assist module cannot be adjusted or repaired and, if damaged or inoperative, it must be replaced.
The microprocessor in the park assist module contains the park assist system logic circuits. The module uses On-Board Diagnostics (OBD) and can communicate with other electronic modules in the vehicle as well as with the diagnostic scan tool using the Controller Area Network (CAN) data bus. This method of communication is also used for park assist system diagnosis and testing through the 16-way data link connector located on the driver side lower edge of the instrument panel.
The module provides voltage to the four park assist sensors located behind the rear bumper fascia. The park assist display is integral to the Electronic Vehicle Information Center (EVIC) and is provided voltage from the Cab Compartment Node (CCN). The module monitors return inputs from each of the sensors on dedicated hard wired data communication circuits and from the CCN over the CAN data bus. The sensor inputs allow the module to determine when an obstacle is in the rear path of the vehicle and enables the module to calculate the relative location of the obstacle, and whether the distance to that obstacle is increasing or decreasing.
Pre-programmed decision algorithms and calibrations allow the module microprocessor to determine the appropriate park assist system outputs based upon the inputs received from the park assist sensors and electronic messages received from other modules in the vehicle over the CAN data bus. When the programmed conditions are met the module sends electronic messages to the CCN over the CAN data bus to obtain the proper park assist system visual and audible outputs. The module also broadcasts electronic messages over the CAN data bus to enable the other electronic features of the park assist system.
The park assist module microprocessor continuously monitors all of the park assist system electrical circuits and components to determine the system readiness. If the module detects a monitored system fault, it sets a Diagnostic Trouble Code (DTC) and sends the appropriate electronic messages to the CCN over the CAN data bus to control operation of certain park assist system audible warnings and textual messages displayed in the Electronic Vehicle Information Center (EVIC) of the instrument cluster.
The park assist module receives battery current on a fused ignition switch output (run-start) circuit through a fuse in the Totally Integrated Power Module (TIPM). The module receives ground through a ground circuit and take out of the body wire harness connected to the body sheet metal. These connections allow the module to be operational whenever the ignition switch is in the START or ON positions.
The hard wired circuits between components related to the park assist module 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 module 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 module or the electronic controls and communication related to park assist module operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.
The park assist sensors are ultrasonic transceivers that are completely controlled by the park assist module. The sensors transmit and receive ultrasonic signals. The sensors each receive battery current and ground in parallel from the module, but are each connected to individual dedicated serial bus communication circuits to the module.
Each sensor membrane is oscillated, then quieted by the module in a pulsing fashion. While the sensor membrane oscillates, it emits an ultrasonic signal. This signal will bounce or echo off of objects in the path of the vehicle. While quieted, each membrane receives the echoes of the ultrasonic signals it and the other sensors have transmitted. The sensors then communicate this echo data over the serial bus lines back to the module. The microprocessor in the module uses the intervals between the ultrasonic transmission and reception data from the sensors to calculate the distance to any obstacles identified by the ultrasonic echoes.
The hard wired circuits between components related to the park assist sensors 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 sensors 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 sensors or the electronic controls and communication related to park assist sensor operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.
Scheme 4
Note. The park assist sensors (3) and the sensor spacers (O-rings) are each available for separate service replacement.
- Disconnect and isolate the battery negative cable.
- From the back of the bumper (2), disconnect the wire harness connector (4) from the park assist sensor (3) connector receptacle.
- Carefully pry the sensor bracket (5) latch features (1) away from the top and bottom latch tabs of the sensor far enough to disengage the sensor from the bracket.
- Disengage the O-ring spacer from around the circumference of the sensor membrane protrusion.
- If required, depress the four locking tabs and remove the sensor brackets from the bumper.