Chime/Buzzer - Operation
OPERATION
CHIME WARNING SYSTEM
The chime warning system operates on battery voltage received through a fuse in the Junction Block (JB) on a non-switched fused B(+) circuit so that the system may operate regardless of the ignition switch position. The chime warning system also monitors the ignition switch position so that some chime features are functional only with the ignition switch in the On position, while others are functional regardless of the ignition switch position.
The chime warning system provides an audible indication to the vehicle operator or occupants under the following conditions:
- Airbag Indicator Warning - The Cab Compartment Node (CCN) transducer will generate one short chime when the ignition switch is in the On position, and an electronic message is received over the Controller Area Network (CAN) data bus from the Occupant Restraint Controller (ORC) requesting "Airbag" indicator illumination. This warning will only occur following completion of the "Airbag" indicator bulb test, and will only occur once during any ignition cycle.
- Compass Mini-Trip Computer Global Reset - The CCN transducer will generate one short chime when the ignition switch is in the On position, and an electronic message is received over the CAN data bus from the optional Compass Mini-Trip Computer (CMTC) requesting that the CMTC average fuel economy, trip odometer and distance to empty data be reset. The CMTC monitors hard wired inputs from the U.S./Metric and Reset button switches to determine the proper reset messages to send to the CCN.
- Door Ajar Indicator Warning - The CCN transducer will generate one short chime when the ignition switch is in the On position, a hard wired input is received indicating that the status of any door ajar switch has changed, and an electronic message is received over the CAN data bus indicating that the vehicle is moving.
- Fasten Seat Belt Indicator Warning - The CCN transducer will generate repetitive chimes at a slow rate to announce that a hard wired input from the seat belt switch indicates that the driver side front seat belt is not fastened with the ignition switch in the On position. The chime warning system also supports the enhanced seat belt reminder (beltminder) when this feature is enabled.
- Gate Ajar Indicator Warning - The CCN transducer will generate one short chime when the ignition switch is in the On position, a hard wired input is received indicating that the status of the liftgate ajar switch has changed, and an electronic message is received over the CAN data bus indicating that the vehicle is moving.
- Head/Park Lamps-On Warning - The CCN transducer will generate repetitive chimes at a fast rate to indicate that hard wired inputs from the driver door ajar switch, the headlamp switch, and the ignition switch indicate that the exterior lamps are turned On with the driver side front door opened and the ignition switch in the Off position. The chimes will continue to sound until the exterior lamps are turned Off, the driver side front door is closed, or the ignition switch is turned to the On position, whichever occurs first.
- Key-In-Ignition Warning - The CCN transducer will generate repetitive chimes at a fast rate to indicate that hard wired inputs from the driver door ajar switch, the ignition switch, and the key-in ignition switch circuitry of the ignition switch indicate that the key is in the ignition lock cylinder with the driver side front door open and the ignition switch in the Off position. The chimes will continue to sound until the key is removed from the ignition lock cylinder, the driver side front door is closed, or the ignition switch is turned to the On position, whichever occurs first.
- Low Fuel Indicator Warning - The CCN transducer will generate one short chime when the low fuel indicator is illuminated by the instrument cluster circuitry. This chime will only occur once during any ignition cycle.
- Low Wash Indicator Warning - The CCN transducer will generate one short chime when the low washer fluid indicator is illuminated by the instrument cluster circuitry. This chime will only occur once during any ignition cycle.
- Overspeed Warning - The CCN transducer will generate repetitive chimes at a slow rate to indicate that the vehicle speed is over a pre-programmed speed value. The CCN monitors electronic vehicle speed messages received over the CAN data bus. This feature is only enabled on an CCN that has been programmed with a Middle East Gulf Coast Country (GCC) code.
- Park Brake Reminder - The CCN transducer will generate one short chime to announce that the hard wired input from the park brake switch and a vehicle speed message input received over the CAN data bus indicate that the park brake is applied and the vehicle is moving. This chime will repeat each time the input conditions are met.
- Sentry Key "Customer Learn" Mode Announcement - The CCN transducer will generate one short chime to confirm that an electronic "Customer Learn" mode message has been received over the CAN data bus to indicate that the Wireless Ignition Node (WIN) is prepared for programming additional sentry key transponders. This chime feature is only active on vehicles equipped with the optional Sentry Key system, and sold in a market where "Customer Learn" programming is an allowed feature.
- Trans Overtemp Indicator Warning - The CCN transducer will generate repetitive chimes at a slow rate when the transmission overtemp indicator is illuminated by the instrument cluster for a high or critical transmission fluid temperature condition. This chime will repeat each time the trans overtemp indicator is cycled from Off to On.
- Turn Signal/Hazard Warning Flasher Emulation - The CCN relay will generate repetitive clicks at a slow rate to emulate an electromechanical flasher when the turn signal or hazard warning system are operating. The CCN relay will generate repetitive clicks at a fast rate to indicate that the right or left turn signal are operating with one or more bulbs inoperative. In either case, the clicks will continue until the turn signal and hazard warning systems are turned off.
- Turn Signal On Warning - The CCN transducer will generate repetitive chimes at a slow rate to indicate that a turn signal has been active continuously for 1.6 kilometers (1 mile) with the vehicle speed greater than 22 kilometers-per-hour (15 miles-per hour). Vehicles built for markets other than the United States and Canada have a revised distance threshold of 4 kilometers for this feature. The chime will continue until the turn signal input becomes inactive or until the vehicle speed message indicates that the speed is less than 22 kilometers-per-hour (15 miles-per-hour), whichever occurs first. The hazard warning flashers will not activate this chime feature.
- Warning Indicator Announcement - The CCN transducer will generate one short chime each time the check gauges indicator is illuminated by the instrument cluster circuitry. The check gauges indicator may be illuminated when any critical engine or transmission systems are operating outside of their normal parameters. The instrument cluster monitors electronic messages received over the CAN data bus to determine when to illuminate the check gauges indicator.
The CCN provides chime service for all available features in the chime warning system. The CCN relies upon its internal programming, numerous hard wired inputs, and electronic message inputs received from other modules over the CAN data bus network to provide the chime warning system features. The internal programming of the CCN determines the priority of each chime request input that is received, as well as the rate and duration of each chime that is to be generated.
The hard wired chime warning system inputs to the CCN may be diagnosed and tested using conventional diagnostic tools and procedures. However, conventional diagnostic methods may not prove conclusive in the diagnosis of the CCN, the CAN data bus, or the electronic messages received by the CCN from other modules. The most reliable, efficient and accurate means to diagnose the CCN, the CAN data bus, or the electronic message inputs used for the chime warning system requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.
PARK ASSIST SYSTEM
The park assist display provides the vehicle operator with visual feedback by illuminating amber or red Light Emitting Diode (LED) units individually or in unison, and audible feedback by energizing an audible tone transducer on the display electronic circuit board to emit either an intermittent or a continuous tone. While the park assist system is active, the number, position and color of the illuminated LED units as well as the audible signal frequency indicate the relative position and distance of obstacles detected at the rear of the vehicle.
When the driver selects Reverse, the system scans for objects behind the vehicle using four sensors located in the rear bumper. A warning display above the rear window provides both visible and audible warnings indicating the range of the object. The system is only active when the transmission gear selector is in the reverse position and the vehicle speed is less than 10 mph (16 Km/h). If the vehicle's Parking/Emergency Brake is applied, the system is deactivated. The system detection length from the rear of the vehicle is 0.3 meters to 1.5 meters. This area extends around the rear side of the vehicle. The system detection height from the ground is 0.2 meters to about 1.5 meters. The radio mutes when the system activates its audible tone.
The display contains two sets of yellow and red Light Emitting Diode's (LED's) that the driver can see as they look over their shoulder while backing up. Each side of the vehicle has its own warning LED's. The system provides a visual warning by illuminating one or more yellow LED's as the vehicle gets closer to the object. As the vehicle continues to approach the object, one red LED is illuminated and the system emits a series of short beeps. The tone will remain constant and both red LED's are illuminated once the vehicle is within 12 inches (30.5 cm) of the object.
The park assist display receives battery current and ground from, and is completely controlled by, the park assist module. The display also contains an electronic communication chip that allows bi-directional communication to occur with the park assist module over a dedicated serial bus line. The microprocessor in the park assist module completely controls the display outputs, 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 illumination intensity of the LED units is also controlled by the park assist module based upon internal programming and electronic panel lamps dimming messages received over the Controller Area Network (CAN) data bus.
When the ignition switch is turned to the ON position, all 16 of the LED units in the display will illuminate in unison for approximately 1 second as a bulb test. This output will be interrupted if the system is active and senses an obstacle. Following the conclusion of the bulb test, when the system is active but no obstacle is detected, the display will indicate system readiness by illuminating the two outermost amber LED units (1) at a reduced intensity. As an obstacle is detected, the outermost amber LED unit (5) on the side of the vehicle where the obstacle was detected will be illuminated at normal intensity and a single short audible tone (one-half second duration) is sounded. Then additional amber LED units (6) will begin illuminating inward (2 or 4) as the obstacle gets closer until, finally, the two red LED units (7) are illuminated.
When the final red LED unit (3) is illuminated, the obstacle is approximately 40 centimeters (16 inches) from the rear corner of the vehicle or approximately 50 centimeters (19.7 inches) from the rear bumper face and an intermittent audible tone will be generated. The frequency of the audible tone will increase as the obstacle continues to become closer until the tone is continuous when the obstacle is about 15 centimeters (6 inches) from the rear corner of the vehicle or about 30 centimeters (11.8 inches) from the rear bumper face. Whenever a park assist audible tone is being generated, the park assist module sends electronic messages to the radio over the CAN data bus to mute the audio system. The audible tone will be cancelled after about two seconds if the detected distance to the obstacle remains constant. See the Park Assist Display Outputs table for additional details.
The system can be turned ON or OFF through the Electronic Vehicle Information Center (EVIC) when the vehicle is in PARK. If the park assist system is turned OFF, a single chime will sound and the EVIC will display the following message "REAR PARK ASSIST OFF", when the vehicle is in reverse.
- Ensure that the rear bumper is free of dirt and debris to keep the system operating properly.
- Jackhammers, large trucks, and other vibrations could affect the performance of the system.
- Ensure that the parking brake is not applied.
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.
If "Service Park Assist System" appears in the EVIC after making sure the rear bumper is clean, proceed to diagnose the system. However, conventional diagnostic methods will prove inconclusive in the diagnosis of the park assist system, its 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. Testing and Inspection for the appropriate diagnostic information.