- Flow of Diagnosis - Start Here

Flow Of Diagnosis.:

1. Verify that the problem exist and verify whether the problem is a intermittent or a constant problem. DO NOT use the A-CHARTS or TROUBLE CODE CHARTS for diagnosing of intermittent problems. For further information use DRIVEABILITY WORKSHEET AND VEHICLE REPAIR HISTORY forms below.
2. Check to make sure vacuum and vapor hose routing is correct and that hoses are not split or cracked.
a. Check to make sure all the electrical connections to sensors and solenoids are clean and have tight connections.
b. Check to make sure all engine grounds are clean and have good connections.
3. Check for updated diagnostic procedures, warranty or recall information.
NOTE: All tests that follow are under TESTING PROCEDURES. Trouble code tests are under DIAGNOSTIC CHARTS.

4. This checks the "On Car Diagnostics" and gives the proper sequence of testing. Refer to HOW TO ENTER DIAGNOSTIC MODE for procedure to enter diagnostics. If there are stored codes this will lead to the proper test. If there is no response or no data displayed continue to the next step. If there is a data display but no codes stored go to step 6.
5. This checks to make sure that the computer is functioning properly and that the "SERVICE ENGINE SOON LIGHT" is working.
6. This checks that all switch tests pass. Refer to ECM DISPLAY for proper procedure. If all switched inputs are operating correctly proceed to next step.
7. This test is contained in the DFI SYSTEM CHECK. It checks that the fuel system is controlling correctly.
8. Go to the symptom the vehicle is exhibiting. This will lead to possible non-computer related failures.

Driveability Worksheet.:

Driveability Worksheet.:

DRIVEABILITY WORKSHEET

Vehicle Repair History.:

Vehicle Repair History.:

VEHICLE REPAIR HISTORY