Overhead Console - Service Information: Overview Dodge Dakota III

Scheme 1

An overhead console (1) is standard on this vehicle and includes the following components

1. Front map/reading lamps (2)
2. Electronic Overhead Module (EOM)

The EOM consists of the trip computer with a blue-green vacuum-fluorescent display screen (4) and the Universal Transmitter (3). The overhead console assembly is mounted by two snap clips and one screw securing it to a molded plastic retainer bracket located above the headliner. The EOM is secured to the overhead console with four screws.

OPERATION

The Electronic Overhead Module (EOM) only operates with the ignition switch in the On position. When the ignition switch is turned to the On position, the Vacuum-Fluorescent Display (VFD) will return to the last function being displayed before the ignition was turned to the Off position. With the ignition switch in the On position, momentarily depressing and releasing the Step push button (4) will cause the EOM to change its mode of operation. Momentarily depressing and releasing the U.S./Metric push button (1) will cause the unit to toggle between U.S. and Metric measurements. Momentarily depressing and releasing the C/T (compass/temperature) push button (5) will cause the EOM to return to the compass/temperature display mode from any other mode.

This EOM features several functions that can be reset. If the RESET push button (2) is depressed for more than one second with the ignition switch in the On position, the trip computer information that can be reset is reset. However, the reset will only occur if the function currently displayed is a function that can be reset. The functions that can be reset are: TRIP ODO, AVG ECO, and ET. All three of these functions can be reset at once by pressing the RESET button twice within 3 seconds while any one of the three functions is selected.

DESCRIPTION

The universal transmitter transceiver is integral to the overhead console (7). The only visible component of the universal transmitter are the three transmitter push buttons (3). The buttons are marked with one, two or three dots, respectively, for identification of each channel.

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, and is available for service only as part of the Electronic Overhead Module (EOM). This unit includes the push button switches for both the transmitter and compass mini trip computer, The Vacuum-Fluorescent Display (VFD) and the plastic module case. (Refer to ELECTRICAL/OVERHEAD CONSOLE/COMPASS/MINI-TRIP COMPUTER - REMOVAL) for EOM replacement.

The universal transmitter operates on a non-switched source of battery current so the unit will remain functional, regardless of the ignition switch position. It can learn and store three separate transmitter radio frequency codes to operate garage door openers, security gates and security lighting. The overhead console display provides visual feedback to the driver, showing which transmitter button is pressed. The system will not send operating signals if the vehicle theft security alarm is armed. This prevents a perpetrator from breaking into a vehicle parked outside a home and using the transmitter system to enter the home.

Scheme 2

If both the Transmitter and the compass mini trip computer display are inoperative, (Refer to ELECTRICAL/OVERHEAD CONSOLE/COMPASS/MINI-TRIP COMPUTER - DIAGNOSIS AND TESTING) for further diagnosis. If the Universal Transmitter is inoperative, but the compass mini trip computer display is operating normally, (Refer to ELECTRICAL/OVERHEAD CONSOLE/UNIVERSAL TRANSMITTER - STANDARD PROCEDURE) for instructions on training the Transmitter. Retrain the Transmitter with a known good transmitter as instructed and test the Transmitter operation again. If the unit is still inoperative, test the universal transmitter with the Radio Frequency Detector special tool as described below

1. Turn the Radio Frequency (RF) Detector ON. A "chirp" will sound and the green power LED will light. If the green LED does not light, replace the battery.
2. Hold the RF detector within one inch of the TRAINED universal transmitter and press any of the transmitters buttons.
3. The red signal detection LEDs will light and the tool will beep if a radio signal is detected. Repeat this test for each button. If any button is inoperative, replace the universal transmitter assembly, «(Refer to ELECTRICAL/OVERHEAD CONSOLE/COMPASS/MINI-TRIP COMPUTER - REMOVAL)»(ref-247649-S20810555502007020100000) .

For complete circuit diagrams, refer to SYSTEM WIRING DIAGRAMS . 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.

The ambient temperature sensor is a variable resistor that operates on a five-volt reference signal sent by the Front Control Module (FCM). The resistance in the sensor changes as temperature changes, changing the temperature sensor signal circuit voltage to the FCM. Based upon the resistance in the sensor, the FCM senses a specific voltage on the temperature sensor signal circuit. The FCM then translates the voltage into a temperature reading that it sent over the Controller Area Network (CAN) data bus to other modules utilizing temperature information.