CEC Introduction: Operation: Servicing

The first step in servicing is to eliminate possible causes of trouble. Be sure that mechanical systems (compression, valves, plugs, transmission) are okay before suspecting the computer system. It has no control over these problems.

Most computer control systems have no serviceable parts. The technician's job is to locate the part that doesn't work and to replace it. Since these systems can be quite complicated, manufac-turers have built in some self-diagnostic features. The computer looks for and indicates its own problems.

With these systems, the technician starts the computer diagnostic program and watches for service codes that indicate a problem. These code numbers can be indicated by flashes of a dash mounted light or pulses on a voltmeter. Small diagnostic testers are now available that will show a direct indication of the code.

Once the codes are known, trouble shooting procedures and charts are used to locate the specific component failure. Without the procedures and charts, troublesome components are harder to locate, but repairs can still be made. One danger is that traditional obvious causes of poor driveability may no longer be the cause now, and parts replacement to resolve a problem is very expensive. The diagnostic programs MUST be used to ensure profitable and accurate repairs.