- Checking the Basics

This section is used to find the correct test procedure for a given symptom. The possible causes and actions in this section are related to computer controlled systems, but may or may not set a DIAGNOSTIC TROUBLE CODE (DTC). It is assumed that the ECM and "MALFUNCTION INDICATOR" light are operational, as well as no trouble codes were retrieved.

Before proceding to the appropriate symptom, perform the following inspection:

NOTE: It is essential that the vehicle has been properly warmed up and is at operating temperature, except when attempting to diagnosis a cold driveablity problem. The catalytic converter and feedback system will not function as designed if this is not achieved. Failure to do so will result in inaccurate test results. Verify the correct symptom from the customer.

VISUALLY CHECK:

1. ECM grounds for being clean and tight.
2. Vacuum hoses for splits, kinks and proper routing.
3. Air leaks at throttle body mounting and intake manifold.
4. Ignition wires for cracking, hardness and proper connections at both the distributor and spark plugs.
5. All wiring for proper connections, pinches and cuts.
6. Harnesses (EST, ESC, etc...) for proper routing.