Component Tests and General Diagnostics

Any diagnosis of the compass mini-trip computer should begin with the use of the DRB III(R) diagnostic tool. For information on the use of the DRB III(R), refer to the appropriate Diagnostic Procedures information.

Compass Mini-Trip Computer (CMTC) data is obtained from the Body Control Module (BCM) on the Programmable Communications Interface (PCI) Data Bus circuit. The CMTC will display dashes (- -) for any of the screens it did not receive the bus messages. The label corresponding to the missing information will be lit. If no CMTC data is displayed, check the PCI Data Bus circuit communications and the BCM. If the dimming level is improper check the PCI Data Bus circuit.