- Important Preliminary Checks

IMPORTANT PRELIMINARY CHECKS BEFORE STARTING
Before using this section, perform the "On-Board Diagnostic (OBD) System Check" and verify all of the following items: 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 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 Cooling System for diagnosis.
^ Scan tool data is within normal operating range, Refer to Typical Scan Data Values. Scan Tool Testing and Procedures
^ Verify the customer complaint and locate the correct symptom in the table of contents. Perform the procedure included in the symptom chart.