A Symptoms

Symptoms - Engine Controls

Important Preliminary Checks Before Starting
Perform the Diagnostic System Check - Engine Controls before using the symptom tables. Verify that all of the following conditions are true:
^ The engine control module (ECM) and the malfunction indicator lamp (MIL) are operating correctly.
^ There are no diagnostic trouble codes (DTCs) stored.
^ The scan tool data is within the normal operating range.
^ Verify the customer concern and locate the correct symptom listed below. Inspect items indicated under that symptom.
^ Several of the symptom procedures direct the technician to perform a visual/physical inspection. This important step can lead the technician to the cause of the problem without further checks and can save valuable time.
^ Verify the correct installation and operation of electronic options, such as lights and cellular phones.

1. Use the following tests when diagnosing a symptom concern:
^ 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
^ Rough, Unstable, or Incorrect Idle and Stalling Rough, Unstable, or Incorrect Idle and Stalling
^ Dieseling, Run-On Dieseling, Run-On
^ Backfire Backfire
2. If the condition cannot be isolated using the appropriate test, refer to Intermittent Conditions for further diagnosis.