A Symptoms

IMPORTANT PRELIMINARY CHECKS BEFORE STARTING
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 in Cooling System. 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.

VISUAL/PHYSICAL CHECK
Several of the symptom procedures call for a careful Visual/physical check. This check can lead to correcting a problem without further checks and can save valuable time. This check includes the following items:
- PCM grounds for being clean, tight, and in the proper location. Refer to Master Electrical Component List and Power and Grounding Component Views in Diagnostic Aids.
- Vacuum hoses for splits, kinks, proper routing, and connections. Refer to the Vehicle Emission Control Information label. Check thoroughly for any type of leak or restriction. Refer to Emission Hose Routing Diagram.
- Intake air system for the following conditions:
- Dirty or damaged air cleaner element or housing
- Damaged or collapsed intake air ducts.
- Poor intake air system connections
- Air leaks at the throttle body and/or intake manifold.
- Throttle body contaminants or deposits.
- Accelerator cable binding or damage.
- Ignition system wiring for incorrect routing and/or poor connections.
- System wiring for routing near high frequency devices (electromagnetic interference (EMI) condition).
- Engine cooling system leaks. Refer to Loss of Coolant in Cooling System. Loss of Coolant

The following Symptom tables are located:
- Hard Start
- Surges/Chuggles
- Lack of Power, Sluggishness, or Sponginess
- Detonation/Spark Knock
- Hesitation, Sag, Stumble
- Cuts Out, Misses
- Poor Fuel Economy
- Poor Fuel Fill Quality
- Rough, Unstable, or Incorrect Idle and Stalling
- Dieseling, Run-On
- Backfire
- Restricted Exhaust in Exhaust System