Engine Controls - Trouble Shooting: Introduction

Before diagnosing symptoms or intermittent faults, perform DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - 2.2L ION article. Use this article to diagnose driveability problems when a current DTC is not present.

Symptom checks are intended to direct the technician to malfunctioning component(s) so that further diagnosis may be performed. A symptom should lead to further testing of specific components or systems, or verification of adjustment specifications.

Use intermittent test procedures to locate intermittent driveability problems that do not occur when the vehicle is being tested. These problems may cause a noticeable driveability problem or cause the Malfunction Indicator Light (MIL) to illuminate on some vehicles.

It is also possible that certain driveability concerns have been rectified by the manufacturer through reprogramming the PCM. Check with manufacturer for latest information on updated programs.

CAUTION: Do not insert test equipment probes into any connector or fuse block terminal. The diameter of the test probes will deform most terminals. A deformed terminal can cause a poor connection, which can result in system failures. Always use the Connector Test Adapter Kit (J 43907) to front probe terminals. Do not use paper clips or other substitutes as they can damage terminals and cause incorrect measurements.

NOTE: For specific testing procedures, see SYSTEM & COMPONENT TESTING - 2.2L ION article. To verify specifications, see SERVICE & ADJUSTMENT SPECIFICATIONS - ION & SATURN "L" SERIES article, or ON-VEHICLE ADJUSTMENTS - CARS article.