How to Use Diagnostic Charts: Overview

Diagnosis of faults is done in three basic steps:

1. Visual inspection
- A careful and thorough visual inspection may quickly identify the cause of a malfunction and eliminate the need for additional diagnostic procedures.

- Diagnosis of vehicle faults always starts with the visual inspection. If the fault is not resolved by the visual inspection, perform the diagnostic test(s).

2. Diagnostic tests
- Each specific fault is diagnosed by following a specific test procedure. It is not necessary to perform all of the tests to diagnose an individual fault.
- Always begin diagnostic testing with Test 1A. This will direct you to the specific test(s) that must be performed in response to the specific vehicle fault.

3. Verification test
- A verification of system operation must always be performed to ensure that the system is operating normally after the cause of a fault has been found and repaired.