Basic Diagnostic Procedures

The most important purpose of diagnostics is to determine which part is malfunctioning quickly, to save time and labor.

A. Identification Of Trouble Symptom
Determine what the problem is based on the symptom.

B. Probable Cause Of Trouble
Look at the wiring diagram and check the system's circuit. Then check the switch, relay, fuse, ground, etc.

C. Location And Repair Of Trouble
1) Using the diagnostics narrow down the causes.
2) If necessary, use a voltmeter, ohmmeter, etc.
3) Before replacing certain component parts (switch, relay, etc.), check the power supply, ground, for open wiring harness, poor connectors, etc. If no problems are encountered, check the component parts.

D. Confirmation Of System Operation
After repairing, ensure that the system operates properly.