A Symptoms

SYMPTOMS

IMPORTANT PRELIMINARY CHECKS BEFORE STARTING
Before using this section, perform the Diagnostic System Check - Vehicle in Vehicle DTC Information and determined that the following items are OK:
- The control module, malfunction indicator lamp (MIL), and check engine are operating correctly.
- There are no DTCs stored.
- The scan tool data is within normal operating range. Refer to Scan Tool Data List. Scan Tool Data, Normal Values and Definitions Diagnostic System Check - Vehicle

Verify the customer complaint, and locate the correct symptom in the table of contents. Inspect 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 condition without further inspections and can save valuable time. This inspection should include:
- Control module grounds for the following conditions:
- A clean connection
- A tight connection
- Proper location
- Vacuum hoses for the following conditions:
- Splits
- Kinks
- Proper connections as shown on the Vehicle Emission Control Information label
- 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