A Important Preliminary Checks

Before using this section, perform Diagnostic System Check - Computers and Controls Systems to verify the following items:
^ The powertrain control module (PCM) and malfunction indicator lamp (MIL) (Service Engine Soon) are operating correctly.
^ There are no DTCs stored.
^ Ensure that the engine coolant temperature (ECT) is not above 130°C (266°F). This will cause the PCM to operate in the Engine Metal Overtemp Mode. While in this state, the PCM will turn OFF four cylinders at a time to prevent the engine coolant temperature from reaching damaging levels. Engine Metal Overtemp can be perceived as a lack of power, engine miss, or rough idle. If the engine is operating in the Engine Metal Overtemp mode, refer to DTC P1258. P1258
^ Scan tool data is within the normal operating range. Refer to Scan Tool Data List. Scan Tool Data, Normal Values and Definitions
^ Verify the customers complaint to reference the correct symptom table.