A Symptoms

SYMPTOMS

IMPORTANT PRELIMINARY CHECKS

BEFORE STARTING
Before using this section, perform the Diagnostic System Check - Vehicle in Vehicle DTC Information and verify all of the following conditions:
- The powertrain control module (PCM), malfunction indicator lamp (MIL), and check engine are operating correctly.
- There are no diagnostic trouble codes (DTCs) stored.
- Scan tool data is within normal operating range. Refer to Scan Tool Data List. Diagnostic System Check - Vehicle Scan Tool Data, Normal Values and Definitions

Verify the customer complaint, and locate the correct symptom in the table of contents. Check the items indicated under that symptom.

VISUAL/PHYSICAL CHECK
Several of the symptom procedures call for a careful visual/physical check. The importance of this step cannot be stressed strongly enough. This step can lead to correcting a problem without further checks and can save valuable time. This check should include:
- PCM grounds for the following conditions:
- Clean connection
- Tight connection
- Proper location
- Vacuum hoses for the following conditions:
- Splits
- Kinks
- Proper connections as shown on the Vehicle Emission Control Information label-Refer to Emission Hose Routing Diagram.
- Leaks
- Restrictions
- Air leaks at the following components:
- Throttle body mounting
- Intake manifold sealing surfaces
- Wiring for the following conditions:
- Proper locations
- Pinches
- Cuts
- Use the following tables when diagnosing a symptom complaint:
- Hard Start
- Surges/Chuggles
- Lack of Power, Sluggishness, or Sponginess
- Detonation/Spark Knock
- Hesitation, Sag, Stumble
- Cuts Out, Misses
- Poor Fuel Economy
- Poor Fuel Fill Quality
- Rough, Unstable, or Incorrect Idle and Stalling
- Dieseling, Run-On
- Backfire
- Malfunction Indicator Lamp (MIL) Inoperative
- Malfunction Indicator Lamp (MIL) Always On