Flow of Diagnosis

Flow Of Diagnosis:

1. Get detailed description of complaint, then Road Test vehicle to verify. Make note of engine condition, engine RPM, Drivers demands for performance, recent repairs and why, frequency of occurences, noted vibrations, squeaks, rattles or decreasing fuel economy and performance.

2. Check Technical Service Bulletins for manual updates, testing procedures, warranty and recall information.

3. VISUALLY INSPECT THE FOLLOWING:

(a) Vacuum hoses for proper routing, tight connections, cracks, kinks, and foreign obstacles (BB).
NOTE: Some vehicle manufacturers use an orifice-insert within a vacuum line as a delay device. Do not mistake as a BB and cut the vacuum line.

(B) Electrical wires for proper routing, tight connections, kinks, abrasions, or damage. Grounds should be clean and tight.

(c) Verify that all required components are properly installed.

(d) Check for air or vacuum leaks around the intake and exhaust manifolds, as well as the throttle body.

(e) Physical condition of components: cracks, corrosion, looseness, modifications or damage.

(f) The Catalytic Converter(s), muffler, exhaust pipes, brackets and hangers for modifications or damage.

(g) Plugged or capped ports at the base of the throttle body or on the intake manifold.

4. Refer to ON-BOARD DIAGNOSTIC CHECK under TESTING PROCEDURES.

5. Proceed to DIAGNOSIS BY SYMPTOM under TESTING PROCEDURES for the symptom which the vehicle is exhibiting.