Diagnostic Readout Box: Description and Operation

VCM 1 (Vehicle Condition Monitor) is the output signal provided to the instrument panel trip computer indicating an engine management system. If a fault occurs while trip computer information is being displayed on the message screen, the fault warning will override the trip computer message.

VCM 2 is a dual purpose output signal to the instrumentation system:

1. Identifies individual engine management system faults when the ignition switch is first turned to position "II" after a fault is detected.
2. While engine is running, provides engine condition information to the trip computer.