Diagnostic Notes

The symptoms and actions in this section are Emission related only, and used to find the correct test procedure for a given symptom. Refer to COMPUTERIZED ENGINE CONTROLS for further diagnosis of electronically controlled engine components. Always start with the FLOW OF DIAGNOSIS for the proper testing sequence. Verify the emission system application to ensure that the vehicle has the given component(s).

NOTE: Except when attempting to diagnose a cold driveability problem, it is essential that the vehicle be properly warmed up to operating temperature. The vehicle should be driven for 10 to 20 minutes, to ensure all systems are functioning during diagnosis. If this is not achieved, the catalytic converter and feedback systems will produce inaccurate test results.