A Important Preliminary Checks

Before using this system, perform A Powertrain On Board Diagnostic (OBD) System Check and verify the following items:
^ The Powertrain Control Module (PCM) and Malfunction Indicator Lamp (MIL) are operating correctly.
^ There are no DTCs stored.
^ Ensure that the engine coolant temperature is not more than 128°C (262°F). This condition will cause the PCM to operate in Coolant Hot mode. While in Coolant Hot mode, the PCM will turn the fuel OFF to 3 cylinders in order to keep the engine temperatures from reaching damaging levels. Coolant Hot mode will be perceived as a lack of power, miss, or rough idle. If the vehicle is operating in Coolant Hot mode, refer to Engine Overheating in Cooling System.
^ The scan tool data is within a normal operating range. Refer to Scan Tool Data List.
^ Verify the customer complaint and locate the applicable symptoms. Perform the procedure included in the Symptom diagnostic table.