DESCRIPTION
Four different overhead console options are available on the CS model. The base overhead console includes a universal transmitter and push buttons. Option two includes the universal transmitter and power liftgate push buttons. (Scheme 17) Option three includes the universal transmitter and power sunroof push buttons. The final option includes all of the features mentioned, universal transmitter, power liftgate and power sunroof push buttons. All overhead consoles are equipped with a internal Compass Mini-Trip Computer (CMTC) module, two reading/courtesy lamps and a storage bin. The overhead console is mounted with one screw and two snap clips to a molded plastic retainer bracket located above the headliner.
Scheme 17
| 1 - Storage Bin Door |
|---|
| 2 - Reading/Courtesy Lamps |
The overhead console CMTC module display and Electronic Vehicle Information Center (EVIC) is built in to the instrument cluster on this model. The instrument panel switch pod contains the US/M, MENU, STEP and RESET push buttons used to control the CMTC and EVIC displays. Refer to INSTRUMENT CLUSTER and INSTRUMENT PANEL SWITCH POD for more information.
DESCRIPTION - COMPASS
When in the compass/temperature mode, the cluster will display the direction in which the vehicle is pointed using the eight major compass headings (Examples: north is N, northeast is NE). The CMTC module contains a self-calibrating compass that requires no adjusting in normal use. The only calibration that may prove necessary is to drive the vehicle in three complete circles at 5 to 8 kilometers-per-hour (3 to 5 miles-per-hour), on level ground, in not less than forty-eight seconds. This will reorient the compass to its vehicle.
The compass will compensate for magnetism the body of the vehicle may acquire during normal use. However, avoid placing anything magnetic directly on the roof of the vehicle. Magnetic mounts for an antenna, a repair order hat, or a funeral procession flag can exceed the compensating ability of the compass unit if placed on the roof panel. Magnetic bit drivers used on the fasteners that hold the overhead console assembly to the roof header can also affect compass operation. If the vehicle roof should become magnetized, the demagnetizing and calibration procedures may be required to restore proper compass operation.
Following are general descriptions of the major components used in the overhead console. Refer to INSTRUMENT CLUSTER for more information.
Ambient air temperature is monitored through ambient temperature messages received from the Front Control Module (FCM) over the Programmable Communications Interface (PCI) data bus circuit. The FCM receives a hard wired input from the ambient temperature sensor. The ambient temperature sensor. (Scheme 18)is a variable resistor mounted to a bracket that is secured with a screw to the left side of the cooling module, behind the front grille.
Scheme 18
For more information on the Front Control Module, refer to the ELECTRONIC CONTROL MODULES article . The ambient temperature sensor cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.
OPERATION
The ambient temperature sensor is a variable resistor. A five-volt reference signal is sent to the sensor by the Front Control Module. The front control module monitors the return signal voltage on a dedicated temperature sensor signal circuit. Based upon the resistance in the sensor, the Front Control Module is programmed to correspond to a specific temperature. The Front Control Module then sends the proper ambient temperature messages over the PCI data bus circuit.
The HVAC temperature display function is supported by the ambient temperature sensor, a wiring circuit, the Front Control Module and the Programmable Communications Interface (PCI) data bus. If any portion of the ambient temperature sensor circuit fails, the Front Control Module should self-diagnose the circuit.
The Compass Mini-Trip Computer (CMTC) is a module located in the overhead console. On CS vehicle's the CMTC module display screen is located in the instrument cluster.
The Compass Mini-Trip Computer module contains a central processing unit and interfaces with other electronic modules in the vehicle over the Programmable Communications Interface PCI data bus circuit.
The CMTC module uses its internal programming and all of its data inputs to calculate the requested data. This data includes the Tire Pressure Monitoring, Compass information, Universal Transmitter, Average Fuel Economy (AFE), Distance To Empty (DTE) and Distance To Service (DTS).
The compass mini-trip computer module cannot be repaired, and is available for service only as a unit. This unit includes the plastic module. If the CMTC module is faulty or damaged, the complete module must be replaced.
The Compass Mini-Trip Computer is wired to both non-switched and ignition switched sources of battery current so that some of its features remain operational at any time, while others may only operate with the ignition switch in the On position. Information collected in the CMTC module is sent to the instrument cluster display via the PCI data bus circuit.
The information collected or generated in the compass mini-trip computer module includes tire pressure monitoring, compass and universal transmitter information.
On CS models, a Universal Transmitter transceiver is standard factory-installed equipment. The universal transmitter transceiver is integral to the overhead console mounted CMTC module. The only visible component of the universal transmitter are the three transmitter push buttons centered in the overhead console. The three universal transmitter push buttons are identified with one, two or three light indicators and raised buttons so that they be easily identified by sight or by feel.
Each of the three universal transmitter push buttons controls an independent radio transmitter channel. Each of these three channels can be trained to transmit a different radio frequency signal for the remote operation of garage door openers, motorized gate openers, home or office lighting, security systems or just about any other device that can be equipped with a radio receiver in the 286 to 399 MegaHertz (MHz) frequency range for remote operation. The universal transmitter is capable of operating systems using either rolling code or non-rolling code technology.
The universal transmitter cannot be repaired or adjusted and if the transmitter is faulty or damaged, the complete CMTC module must be replaced. If the universal transmitter push buttons are faulty or damaged the complete overhead console housing assembly must be replaced.
The universal transmitter operates on a non-switched source of battery current so the unit will remain functional, regardless of the ignition switch position. For more information on the features, programming procedures and operation of the universal transmitter, see the owner's manual in the vehicle glove box.
See also:
• BODY DIAGNOSTIC PROCEDURES