Engine Controls - Tests W/O Codes 1.0 &1.3L: Introduction

Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK in the TESTS W/CODES article before attempting to diagnosis symptoms or intermittent faults. Use this article to diagnose driveability problems after it is determined that:

PCM and Malfunction Indicator Light (MIL) are operating properly.
There are no Diagnostic Trouble Codes (DTCs) set, or there is a DTC but no MIL.
A thorough visual and physical check has been performed.

Symptom checks can direct technician to malfunctioning component(s) for further diagnosis. A symptom check should lead to a specific component, system test or an adjustment.

Use intermittent test procedures to locate driveability problems that DO NOT occur when vehicle is being tested. These test procedures should also be used if a soft (intermittent) trouble code was present, but no problem was found during self-diagnostic testing.

NOTE: Some driveability problems may have been corrected by manufacturer with a revised computer calibration chip or computer control unit. Check with manufacturer for latest chip or computer application. Check if any Technical Service Bulletins (TSBs) apply to vehicle.

NOTE: For specific system or component testing procedures, see the SYSTEM/COMPONENT TESTS article. For specifications, see the ADJUSTMENTS article or see the SPECIFICATIONS article.