- Important Preliminary Checks

BEFORE STARTING
Before using this section you should have performed the "On-Board Diagnostic (OBD) System Check" and determined that:
1. The PCM and the Malfunction Indicator Lamp (MIL) "Service Engine Soon" are functioning correctly.
2. There are no DTC(s) stored, or there is a DTC but no MIL (Service Engine Soon).

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

VISUAL/PHYSICAL CHECK
Several of the symptom procedures call for a careful visual/physical check. This check should include:
^ Wiring for proper connections, pinches and cuts.
^ PCM grounds for being clean, tight and in their proper location.
^ 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.
^ Air leaks at throttle body mounting area and intake manifold sealing surfaces.

NOTE: The importance of this step cannot be stressed too strongly - it can lead to correcting a problem without further checks and can save valuable time