- Important Preliminary Checks

Before using this section, perform the Powertrain On-Board Diagnostic (OBD) System Check and verify all of the following items:

^ The PCM and Malfunction Indicator Lamp (MIL) are operating correctly.

^ There are no DTC(s) stored.

^ Ensure that the engine coolant temperature is not above 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 fuel OFF to three cylinders to keep 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 Cooling for diagnosis.

^ Scan tool data is within normal operating range. Refer to Typical Scan Data Values.

^ Verify the customer complaint and locate the applicable symptoms. Perform the procedure included in the symptom diagnostic table.