Before Using This Section
Before using this section, you should have performed the Diagnostic System Check - Vehicle and determined that the following criteria:
| • | The control module and the malfunction indicator lamp (MIL) are operating correctly. |
| • | There are no diagnostic trouble codes (DTCs) stored, or a DTC exists but without MIL. |
Several of the following symptom procedures call for a careful visual and physical check. The visual and physical checks are very important. The checks can lead to correcting a problem without further checks which may save valuable time.
Visual and Physical Checks
Check the following items:
| • | The control module grounds for being clean, tight, and in their proper location |
| • | The vacuum hoses for splits, kinks, and proper connections, as shown on the Vehicle Emission Control Information label |
| • | The wiring for the following items: |
| • | The following symptom tables contain groups of possible causes for each symptom. The order of these procedures is not important. If the scan tool readings do not indicate the problems, then proceed in a logical order, easiest to check or most likely
to cause first. In order to determine if a specific vehicle is using a particular system or component, refer to
Engine Controls Schematics
for an application. |
Verify Customer's Concern
Locate the correct symptom table. Check the items indicated under that symptom from the following symptom tables:
