Diagnosis And Testing - Compass Mini-Trip Computer

WARNING: This page is about a different car, the 2004 Chrysler Pacifica. However, it is still accessible from the selected car via links, so may be relevant.

A DRB III(R) scan tool is required for checking the PCI Data Bus circuit and the compass mini-trip computer.

Remove the overhead console from the head-liner. Check for battery voltage at the fused B(+) circuit cavity of the CMTC module. If OK, go to Step 2. If not OK, repair the open fused B(+) circuit as required.
Turn the ignition switch to the Off position. Disconnect and isolate the battery negative cable. Check for continuity between the ground circuit cavity of the CMTC module and a good ground. There should be continuity. If OK, go to Step 3. If not OK, repair the open ground circuit as required.
Connect negative battery cable. Turn the ignition switch to the On position. Check for battery voltage at the fused ignition switch output (run/start) circuit cavity of the CMTC module. If OK, the voltage and ground supply to the module is OK at this time. If not OK, repair the open fused ignition switch output (run/start) circuit as required.

NOTE: If the compass functions, but accuracy is suspect, it may be necessary to perform a variation adjustment. This procedure allows the compass unit to accommodate variations in the earth's magnetic field strength, based on geographic location. Refer to COMPASS VARIATION ADJUSTMENT .

NOTE: If the compass reading displays a blank, and only "CAL" appears in the display, demagnetizing may be necessary to remove excessive residual magnetic fields from the vehicle. Refer to COMPASS DEMAGNETIZING .