SYMPTOM RELATED DIAGNOSTICS

Engine Brake Verbal Complaint

When performing electrical tests, it is important to wiggle wires and connectors to identify intermittent connection problems.

On some chassis models, pin 86 of the engine brake relay connector is connected to ground through the dash switch. On other models it is connected through V-MAC II. Check the wiring diagram supplied with the chassis.

Perform this diagnostic procedure when the engine brake does not work, does not turn OFF at the proper time or performs erratically.

This diagnostic assumes a particular wiring for the engine brake. Please review the diagram supplied with the chassis to verify the validity of each test step.