- Important Preliminary Checks

BEFORE USING THIS SECTION
Before using this section you should have performed the "On-Board Diagnostic System Check" and determined that: Testing and Inspection
1. The control module and Malfunction Indicator Lamp (MIL) (Service Engine Soon) are operating correctly.
2. There are no diagnostic trouble codes stored, or there is a diagnostic code but no MIL (Service Engine Soon).
^ Several of the following symptom procedures call for a careful visual/physical check.

The importance of visual/physical checks cannot be over stressed, because they can lead to correcting a problem without further checks and can save valuable time.

BEFORE STARTING
This check should include:
^ Control module grounds for being clean, tight, and in their proper location.
^ Fuel lines, pipes and hoses for leaks or restrictions.
^ Vacuum hoses for splits, kinks and proper connections, as shown on "Vehicle Emission Control Information" label. Check thoroughly for any type of leak or restriction.
^ Wiring for proper connections, pinches, and cuts.
^ The following symptom charts contain groups of possible causes for each symptom and cover several engines. These procedures are not necessarily meant to be done in consecutive order. If Tech 1 scan tool readings do not indicate the problems, then proceed in a logical order, easiest to check or most likely cause first. To determine if a particular system or component is used on a specific vehicle, refer the "Control Module Wiring Diagrams" for application.

SYMPTOM
Verify the customer complaint, and locate the correct symptom in the table of contents. Check the items indicated under that symptom. Testing and Inspection