Diagnosis And Testing - Compass Mini-Trip Computer
WARNING: This page is about a different car, the 2004 Dodge Pickup and 2004 Dodge Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
Compass Mini-Trip Computer (CMTC) data is obtained from other electronic modules (CCN, FCM and JTEC) on the J1850 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 compass mini-trip computer data is displayed, check the J1850 Data Bus circuit communications and the other modules.
Refer to OVERHEAD CONSOLE DIAGNOSIS AND TESTING for instructions on performing a CMTC module Self-Diagnostic Test. The DRB III(R) is recommended for checking the J1850 Data Bus circuit and the other modules. Perform the CMTC self diagnosis before replacing the CMTC module.