Flow of Diagnosis

Flow Of Diagnosis:

FLOW OF DIAGNOSIS

Driveability Worksheet:

DRIVEABILITY WORKSHEET

Vehicle Repair History:

VEHICLE REPAIR HISTORY

1. Complete the VEHICLE REPAIR HISTORY and the DRIVEABILITY WORKSHEET, getting a detailed description of the complaint. Verify condition by road testing the vehicle.
Perform underhood inspection.

VISUALLY INSPECT THE FOLLOWING:
a. Vacuum hoses for proper routing, tight connections, splits, 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. Vacuum fittings for improperly capped or plugged ports. Be sure to check the throttle body area, also.
c. Electrical and ignition wires for proper routing, cracking, hardness and tight connections at both the distributor and the spark plugs, kinks, and abrasions. Ground connections should be clean and tight.
d. Verify that all components are properly installed and have not been modified or damaged.
e. Check for air or vacuum leaks around the intake and exhaust manifolds, as well as the throttle body.
f. The catalytic converter(s), muffler, exhaust pipes, brackets, and hangers for modifications or damage.

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

3. The CHECK ENGINE light is used to indicate a malfunction within a computer controlled circuit, regardless if lit intermittently, flashing, or steadily.

4. EEC IV QUICK TEST will direct you to perform the necessary Self-Diagnostic procedures, which will display any stored codes from the computer's memory. From the QUICK TEST you will be directed to either PIN POINT TEST Procedures or Diagnosis By Symptom for further testing of the Computerized Engine Controls.

5. Code 11 (PASS) indicates no codes are stored.
Code 10 acts a separator between a Hard Fault and an Intermittent Fault. Codes other than 10 or 11 indicate a malfunction in the circuit or with the component, indicated by the code.

6. PIN POINT TEST: This is where actual component testing takes place. The PIN POINT TEST will provide testing procedures for sensors or actuators based on the results of previous test procedures (QUICK TEST).
DIAGNOSIS BY SYMPTOM: You may be directed to this section by either the QUICK TEST or PIN POINT TEST. If either of these test indicate there are no computer related problems they may direct you to this section to correct faults not related to the EEC-IV System.

7. See DIAGNOSIS BY SYMPTOM - EMISSION RELATED under TESTING PROCEDURES for symptom vehicle is exhibiting. Follow the procedures as outlined for given symptom.