Compass: Description and Operation

COMPASS MINI TRIP COMPUTER

Compass/Mini-Trip Computer:

The Compass Mini-Trip Computer (CMTC) system is located in the center of the instrument panel, between the HVAC outlets. The Compass Mini-Trip Computer is an electronic control module with a vacuum fluorescent display and two function buttons. The Compass Mini-Trip Computer communicates on the Programmable Communication Interface (PCI) Data Bus Circuit.

The functions that are available via activation of the STEP button are as follows:
- Compass and Temperature
- Average Fuel Economy
- Distance to Empty
- Instantaneous Fuel Economy
- Trip Odometer
- Elapsed Time
- Blank Screen

The Compass Mini-Trip Computer cannot be repaired and, if faulty or damaged it must be replaced. The incandescent lamp for the STEP and US/METRIC button illumination is serviceable. Consult your Mopar� Parts Catalog for a specific part number.

Actuation of the STEP button will cause the Compass Mini-Trip Computer to change mode of operation and actuation of the US/M button will toggle between English and Metric unit of measurement. A reset of the trip computer information is accomplished by actuating the Step and US/M buttons simultaneously. To reset only the trip condition currently displayed, press and release the STEP and US/M buttons simultaneously for one second until a chime sounds. To reset all trip conditions, hold down the STEP and US/M buttons simultaneously (about 2 seconds) until a second chime sounds and then release the buttons.

The Compass Mini-Trip Computer is active only when the ignition switch is in the ON position. When the ignition switch is turned ON, the Compass Mini-Trip Computer will return to the last function screen that was displayed prior to the ignition being turned OFF.

COMPASS MINI-TRIP COMPUTER MESSAGES
The Compass Mini-Trip Computer will not display information for any of the screens for which it did not receive the proper data over the Programmable Communication Interface (PCI) data bus for that particular screen.

The Compass Mini-Trip Computer receives the following messages from the Body Control Module (BCM):
- Verification of US/M Status
- Display Brightness (Dimming) and Lamp Status
- Trip Odometer Data
- Elapsed Ignition On Time Data
- Fuel Efficiency (Average and Instantaneous)
- Distance to Empty
- Outside Temperature

The Compass Mini-Trip Computer transmits the following messages to the Body Control Module (BCM):
- Status Request : Beep, Reset, US/M Toggle
- Current Display
- Compass Heading

The Compass Mini-Trip Computer receives the following message from the Single Board Engine Controller (SBEC):
- Vehicle Speed