Flow of Diagnosis

STEP 1 Listening To The Customer.

Listening to the customer and documenting the conditions which exist when the problem occurs is critical to properly diagnosing an electrical incident. It may also be important to determine if the car has had any accessories recently installed or if any service work (collision repair, etc.) has been recently performed.

STEP 2 Verify the parameters of the incident.

Whenever possible, you should operate the complete system to verify the customers comments. Try to confirm the symptom(s) and under what conditions the incident occurs.

STEP 3 Get the proper diagnosis materials together.

Before beginning the diagnosis, make sure you have all of the necessary information. Along with these Fix Tips you should have the Power Supply Routing information. You should make sure you have a thorough understanding of how the system operates. Based upon the customers comments and your knowledge of the circuit operation, you should be able to identify which component(s) could cause the incident.

STEP 4 Inspect the system.

Inspect the system to find the cause of the symptom. Start the diagnosis by determining the location of the electrical units involved. Inspect each component to verify that it is mechanically free to operate and that all connectors and harnesses are securely connected and properly routed. Systematically check the circuits involved, using the Harness Layouts and Power Supply Routing. Determine which circuit is the cause of the incident and whether it is a wiring problem or a component problem.

STEP 5 Repair or replace.

Repair or replace the incident component or electrical circuit.

STEP 6 Verify the system works properly under all conditions.

Once you have repaired the circuit or replaced a component you need to operate the system in all modes and particularly under the circumstances which resulted in the customers initial complaint.