Important Preliminary Inspections Before Starting

Perform Diagnostic System Check - Vehicle in Vehicle DTC Information before using the symptom tables, and verify that all of the following are true:

• The powertrain control module (PCM) and malfunction indicator lamp (MIL) are operating correctly.
• There are no DTCs stored.
• Verify that the engine is not in a torque reduction mode. The PCM turns certain injectors OFF or reduces the engine timing when the PCM detects an over torque condition or an abusive maneuver.
• Verify that the engine coolant temperature (ECT) 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 Overheating in Engine Cooling for diagnosis.
• The scan tool data is within the normal operating range, refer to Scan Tool Data List .
• Verify the customer concern and locate the correct symptom in the table of contents. Inspect the items indicated under that symptom.