A Important Preliminary Checks

Perform A Powertrain On Board Diagnostic (OBD) System Check before using the Symptom Tables, and verify all of the following are true:
^ The PCM and MIL (Service Engine Soon) are operating correctly.
^ There are no DTCs stored.
^ Ensure that the engine coolant temperature is not above 132°C (270°F). This condition causes the PCM to operate in Engine Coolant Over temperature-Fuel Disabled Mode. While in Engine Coolant Over temperature-Fuel Disabled Mode, the PCM turns fuel off to four cylinders at a time to keep engine temperatures from reaching damaging levels. The customer perceives Engine Coolant Over temperature-Fuel Disabled Mode as a lack of power, miss, or rough idle. If the engine operates in Engine Coolant Over temperature-Fuel Disabled Mode, refer to Engine Overheating in Engine Cooling.
^ The scan tool data is within the normal operating range.
^ Verify the customers concern, and locate the correct symptom in the table of contents. Inspect the items indicated under that symptom.
^ Several of the symptom procedures ask for a thorough Visual/Physical inspection. This step is extremely important - It can lead to correcting a condition without further inspections and can save valuable time.
^ If the condition exists as a start and stall, search for DTCs related to the vehicle theft deterrent system. Inspect for improper installation of electrical options such as lights, cellular phones etc.
^ Use the following tables when diagnosing a symptom concern.
^ If you cannot isolate the condition with the appropriate table, refer to Intermittent Conditions for further diagnosis.

- Intermittent Conditions Intermittent Conditions
- Hard Start Hard Start
- Surges/Chuggles Surges/Chuggles
- Lack of Power, Sluggishness, or Sponginess Lack of Power, Sluggishness, or Sponginess
- Detonation/Spark Knock Detonation, Spark Knock
- Hesitation, Sag, Stumble Hesitation, Sag or Stumble
- Cuts Out, Misses Cuts Out, Misses
- Poor Fuel Economy Poor Fuel Economy
- Poor Fuel Fill Quality Poor Fuel Fill Quality
- Rough, Unstable, or Incorrect Idle and Stalling Rough, Unstable, or Incorrect Idle and Stalling
- Dieseling, Run-On Dieseling, Run-On
- Backfire Backfire