Engine Controls - Tests W/O Codes: Introduction

NOTE: For specific testing procedures, see the I - SYS/COMP TESTS article. For specifications, see the SPECIFICATIONS or the ADJUSTMENTS article in this section. See below:

For 2.5L Specifications: SPECIFICATIONS - 2.5L DIESEL
For 2.5L System & Component tests: SYSTEM/COMPONENT TESTS - 2.5L DIESEL
For 2.5L Adjustment Procedures: ADJUSTMENTS - 2.5L DIESEL
For 3.5L Specifications: SPECIFICATIONS - 3.5L DIESEL
For 3.5L Adjustment Procedures: ADJUSTMENTS - 3.5L DIESEL
For 3.5L System & Component tests: SYSTEM/COMPONENT TESTS - 3.5L DIESEL

Before diagnosing symptoms or intermittent faults, perform test procedures in the appropriate TESTS W/CODES article. See below. Use this article to diagnose driveability problems existing when a hard fault code is not present or vehicle is not equipped with a self-diagnostic system.

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.

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

If no fault codes are present and driveability or customer complaints are present, perform functional test on ELR, EGR, and P-2 control on 5-cylinder or perform functional test on ELR and EGR on 6-cylinder. See appropriate FUNCTIONAL TEST under DIAGNOSTIC TESTS in the appropriate TESTS W/CODES article See below..

For 2.5L testing with codes: TESTS W/CODES - 2.5L DIESEL
For 3.5L testing with codes: TESTS W/CODES - 3.5L DIESEL