Diagnostic Readout Box: Description and Operation

VCM 1 (Vehicle Condition Monitor) is the output signal to the instrumentation system indicating an engine management system fault.

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.