Trip Computer: Description and Operation

COMPASS/MINI-TRIP COMPUTER (CMTC)
The Compass/Mini-Trip Computer (CMTC) system is located in the overhead console. The CMTC consists of an electronic control module with a vacuum fluorescent display (VFD) and function switches. The CMTC displays to the driver the direction the vehicle is traveling and the current outside temperature, as well as the following traveler navigational information: average fuel economy (AVG ECO), distance to empty (DTE), instantaneous fuel economy (ECO), elapsed time (ET), and trip odometer (ODO). The information needed for the traveler functions is received over the CCD bus from the Body Control Module.

Compass Mini-Trip Computer (CMTC) Switches and Display:

The CMTC module in the overhead console has three buttons used to select various functions. The CMTC selector buttons will not operate until the ignition is in the RUN position.

When the ignition switch is first turned to the RUN position, the CMTC display will:
- Blank momentarily
- Light all segments of the VFD for one second
- Blank momentarily
- Return to the last mode setting selected before the ignition was last switched OFF

Actuating the STEP switch will cause the CMTC to change mode of operation when ignition is ON. Example:
- Compass/Temperature
- Trip odometer (ODO)
- Average miles per gallon (AVG ECO)
- Instant miles per gallon (ECO)
- Distance to empty (DTE)
- Elapsed time (ET)
- Off

If the Compass/Mini-Trip Computer has been replaced, it may be necessary to reset the calibration.

Setting The Compass
The compass/mini-trip module is self-calibrated and requires no adjustment. The word CAL will be displayed to indicate that the compass is in the fast calibrating mode. CAL will turn off after the vehicle has gone in three complete circles without stopping, in an area free of magnetic disturbance.

If the module displays the temperature while the compass is blank or shows a false reading, the vehicle must be demagnetized.

If the compass still goes blank after the vehicle is demagnetized, the compass/mini-trip module must be replaced.

Setting The Variance:

Setting The Variance
Variance is the difference between magnetic north and geographic north. To determine the variance for the area you are in, refer to the following zone map provided. The number shown for your area is the variance number for your area.

1. Set the Compass/Mini-Trip Console (CMTC) to compass/temperature mode.
2. Press and hold down the RESET button for 5 seconds.

NOTE: If the button is held for 10 seconds instead of 5, the CMTC will set the variance to 8 and enter the fast calibration mode.

3. The VAR light will come on and the last variance setting will be displayed.
4. Press the STEP button to set the zone number.
5. Press the US/M button and resume normal operation.

NOTE: DO NOT ATTACH ANY MAGNETIC DEVICE SUCH AS A MAGNETIC CB ANTENNA TO THE VEHICLE. THIS CAN CAUSE THE COMPASS TO GIVE FALSE READINGS.