Compass Mini Trip Computer - Simplified Design
NUMBER: 08-28-99GROUP: Electrical
DATE: Aug. 20, 1999
SUBJECT:
Simplified Compass Mini Trip Computer Calibration
MODELS:
2000 (BR/BE) Ram Truck
NOTE:
THIS BULLETIN APPLIES TO VEHICLES EQUIPPED WITH THE COMPASS MINI TRIP COMPUTER (SALES CODE CUS).
DISCUSSION:
The subject model vehicles are shipped from the assembly plants with the compass mini trip computer NOT calibrated. This will be identified by "CAL" displayed on the compass mini trip computer.
NOTE:
IF "CAL" IS NOT DISPLAYED ON THE COMPASS MINI TRIP COMPUTER, THE COMPASS CALIBRATION OCCURRED DURING NORMAL IN-TRANSIT VEHICLE MANEUVERING.
If "CAL" is displayed on the Compass Mini Trip Computer, the Compass Mini Trip Computer must be calibrated prior to delivering the vehicle to the owner. The calibration process for the subject model vehicles is now simpler than previous models and does not require specific vehicle speeds or specific circle diameters. To calibrate the compass mini trip computer, drive the vehicle in a complete circle until "CAL" is no longer displayed on the compass mini trip computer. The calibration can be accomplished during the pre-delivery inspection road test and therefore does not require any additional time for predelivery.
NOTE:
THE LOCATION FOR CALIBRATING THE VEHICLE SHOULD BE ON A LEVELED AREA WITH A MINIMUM DISTANCE OF 50 FEET FROM LARGE METAL OBJECTS, POWER LINES, BUILDINGS, OR LARGE STEEL STRUCTURES.
If "CAL" is not displayed on the Compass Mini Trip Computer and it appears that the compass is not accurate, the Compass Mini Trip Computer must be recalibrated again. To recalibrate the Compass Mini Trip Computer, press the STEP button until Compass/Temperature is displayed. Then, simultaneously press the STEP and USIM buttons until "CAL" (approximately six seconds) appears on the display. Drive the vehicle in a complete circle until "CAL" is no longer displayed on the compass mini trip computer.
Once the calibration setting is complete, the compass may need to have its variance set. Compass variance, also known as magnetic declination, is the difference in angle between true geographic north and magnetic north. In some locations, the difference between true geographic north and magnetic north is great enough to give false readings on the compass mini trip computer. If this occurs, the compass mini trip computer must have the variance set.
To set the variance, ensure that the compass/temperature information is displayed on the compass mini trip computer. Then, momentarily depress the U.S./Metric and the Step buttons simultaneously for less than one second. The compass mini trip computer will enter into the variation adjustment mode and display the current variance zone number along with "VAR."
For your geographic variance zone location, refer to Figure 1. Then, depress and release the Step button to step through the zone number until the zone number for your geographic location appears in the display. After five seconds, the displayed zone will automatically be set into the compass mini trip computer module's memory and normal operation will resume.
NOTE:
IF "CAL" IS STILL ILLUMINATED AFTER COMPLETING THE CALIBRATION PROCEDURE, THE ROOF PANEL MAY BE MAGNETIZED. REFER TO THE 2000 RAM TRUCK SERVICE MANUAL (PUBLICATION NO. 81-370-0108), GROUP 8V FOR INFORMATION REGARDING COMPASS MINI TRIP COMPUTER DEMAGNETIZING PROCEDURE.
POLICY: Information Only