Visual/Physical Check

- Check the Control Module grounds for being clean, tight and in their proper location.

- Check the vacuum hoses for splits, kinks and proper connections, as shown on the Vehicle Emission Control Information label.

- Check thoroughly for any type of leak or restriction.

- Check for air leaks at all the mounting areas of the intake manifold sealing surfaces.

- Check the wiring for the following items:

- Proper connections

- Pinches

- Cuts

- The following symptom tables contain groups of possible causes for each symptom and cover several engines. 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 the Control Module Wiring Diagrams for an application.