Verify Customer Complaint

COMPLAINT VERIFICATION
Whenever possible the technician should personally verify the complaint.
^ Having experienced the malfunction, you will be less likely to attempt to repair a non-existent fault.

MALFUNCTION VERIFICATION
Automotive control systems are easily misunderstood, leading to repairs that attempt to force a system to perform in a way it was never intended to.
^ Always compare system operation to normal system operation as described in either the owners manual or DESCRIPTION AND OPERATION.
^ When possible compare vehicle operation with that of a known good vehicle.

Intermittent Repair Simulation Chart:

INTERMITTENT PROBLEM SIMULATION
In order to duplicate an intermittent problem, it is effective to create similar conditions for component parts, under which the problem might occur.

Perform the activity listed under Service procedure in the chart and note the result.

PREVIOUS REPAIRS
The vehicle repair history can provide explanations to unusual complaints which elude normal troubleshooting attempts. Incorrect components or unapproved repairs can have subtle influences on seemingly unrelated systems.
^ Always attempt to get the "whole story" from the customer.
^ When possible check the system or component which was last repaired.