A Important Preliminary Checks

Perform the Diagnostic System Check-Computers and Controls Systems before using the Symptom Tables, and verify that all of the following conditions are true:
^ The powertrain control module (PCM) and the malfunction indicator lamp (MIL) are operating correctly.
^ There are no DTCs stored.
^ The engine coolant temperature is not above 130°C (266°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 the fuel OFF to 4 cylinders at a time in order to keep the engine temperatures from reaching damaging levels. The system perceives Engine Coolant Over Temperature as a lack of power, a miss, or a rough idle. If the vehicle is operating in Engine Coolant Over Temperature/Fuel Disabled Mode, refer to Engine Overheating in Cooling System for diagnosis. Symptom Related Diagnostic Procedures
^ The scan tool data is within the normal operating range.
Refer to Scan Tool Data List. Scan Tool Data, Normal Values and Definitions
^ Verify the customer 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 careful visual and physical check. This step is extremely important, and can lead to correcting a problem without further checks and can save valuable time.
^ If the intermittent condition exists as a start and then a stall, inspect for any DTCs relating to the theft deterrent system. Verify the proper installation of electrical options such as lights and cellular phones.

1. Use the following tables when diagnosing a symptom concern:
^ Hard Start
^ Surges/Chuggles
^ Lack of Power, Sluggishness, or Sponginess
^ Detonation/Spark Knock
^ Hesitation, Sag, Stumble
^ Cuts Out, Misses
^ Poor Fuel Economy
^ Rough, Unstable, or Incorrect Idle and Stalling
^ Dieseling, Run-On
^ Backfire
2. If the condition cannot be isolated using the appropriate table, refer to Intermittent Conditions for further diagnosis. Intermittent Conditions