- Important Preliminary Checks

Important Preliminary Checks Before Starting
Perform the Powertrain OBD System Check before using the Symptom Tables, and verify all of the following are true: Testing and Inspection
^ The Powertrain Control Module (PCM) and Malfunction Indicator Lamp (MIL) (Service Engine Soon) are operating correctly.
^ There are no DTC(s) stored.
^ Ensure that 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 four cylinders at a time in order to keep engine temperatures from reaching damaging levels. The system perceives Engine Coolant Over temperature as a lack of power, miss, or rough idle. If the vehicle is operating in Engine Coolant Over temperature-Fuel Disabled Mode, refer to Engine/Engine Cooling for diagnosis.
^ The scan tool data is within the normal operating range, refer to Engine Scan Tool Data List.
^ Verify the customer concern, and locate the correct symptom in the table of contents. Check the items indicated under that symptom.