• The PCM monitors CKP sensor input signal interval time. The PCM calculates the change of interval time for each cylinder. If the change of interval time exceeds the preprogrammed criteria, the PCM detects a misfire in the corresponding cylinder. While the engine is running, the PCM counts the number of misfires that occurred at 200 crankshaft revolutions and 1,000 crankshaft revolutions and calculates the misfire ratio for each crankshaft revolution. If the ratio exceeds the preprogrammed criteria, the PCM determines that a misfire, which can damage the catalytic converter or affect emission performance, has occurred.

• This is a continuous monitor (misfire).

• The MIL illuminates if the PCM detects the misfire which affects emission performance in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM.

• The MIL flashes if the PCM detects a misfire which can damage the catalytic converter during the first drive cycle.

• PENDING CODE is available if the PCM detects the misfire which affects emission performance during first drive cycle.

• FREEZE FRAME DATA (Mode 2)/Snapshot data is available.

• The DTC is stored in the PCM memory.

• Erratic signal to PCM

• CMP sensor connector or terminals malfunction

• CMP sensor malfunction

• CKP sensor connector or terminals malfunction

• CKP sensor malfunction

• Ignition system malfunction

• Excessive air suction in intake air system (between MAF sensor and intake manifold)

• MAF sensor malfunction

• Fuel supply system malfunction or improper fuel line pressure

• Purge solenoid valve malfunction

• Improper operation of variable valve timing control system

• EGR valve malfunction

• Engine malfunction

• PCV valve malfunction

• Poor quality fuel

• PCM malfunction

• Have the FREEZE FRAME DATA (Mode 2)/snapshot data and DIAGNOSTIC MONITORING TEST RESULTS (misfire related) been recorded?

• Verify related Service Information availability.

• Is any related Service Information available?

• If the vehicle is not repaired, go to the next step.

• Turn the ignition switch off, then to the ON position (engine off).

• Perform the Pending Trouble Code Access Procedure and DTC Reading Procedure. (See ON-BOARD DIAGNOSTIC TEST [L5].)

• Are any other PENDING CODEs and/or DTCs present?

• Access the following PIDs using the M-MDS: (See ON-BOARD DIAGNOSTIC TEST [L5].)

• Is there any signal that is far out of specification when the ignition switch is turned to the ON position and the engine idles? (See PCM INSPECTION [L5].)

• Access the same PIDs as in Step 4 under the FREEZE FRAME DATA (Mode 2) conditions. (See ON-BOARD DIAGNOSTIC TEST [L5].)

• Is there any signal which causes drastic changes?

• Turn the ignition switch off.

• Disconnect the CMP sensor connector.

• Inspect for poor connection (such as damaged/pulled-out pins, corrosion).

• Is there any malfunction?

• Inspect the CMP sensor. (See CAMSHAFT POSITION (CMP) SENSOR INSPECTION [L5].)

• Is there any malfunction?

• Disconnect the CKP sensor connector.

• Inspect for poor connection (such as damaged/pulled-out pins, corrosion).

• Is there any malfunction?

• Inspect the CKP sensor. (See CRANKSHAFT POSITION (CKP) SENSOR INSPECTION [L5].)

• Is there any malfunction?

• Perform the Spark Test. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [L5])

• Is a strong blue spark visible at each cylinder?

• Remove the spark plug. (See SPARK PLUG REMOVAL/INSTALLATION [L5].)

• Inspect the spark plug. (See SPARK PLUG INSPECTION [L5].)

• Is there any malfunction?

• Inspect the ignition coil related wiring harness condition (intermittent open or short) for all cylinders.

• Is there any malfunction?

• Inspect the ignition coil for all cylinders. (See IGNITION COIL INSPECTION [L5].)

• Is there any malfunction?

• Access the MAF PID using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [L5].)

• Race the engine and verify that the MAF PID changes quickly according to change in the engine speed.

• Is the MAF PID response normal? (See PCM INSPECTION [L5].)

• Inspect for air leakage between the following:

• Is there any leakage?

• Turn the ignition switch off.

• Inspect the fuel line pressure while the engine running. (See FUEL LINE PRESSURE INSPECTION [L5].)

• Is there any malfunction?

• Visually inspect the leakage from fuel line.

• Is there any leakage?

• Visually inspect the foreign materials or stain inside fuel filter.

• Is there any foreign materials or stain?

• Turn the ignition switch off.

• Connect the vacuum pump to the purge solenoid valve and apply vacuum to the solenoid.

• Verify that the solenoid holds vacuum.

• Access the EVAPCP PID of simulation item using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [L5].)

• Set the purge solenoid value to 100% for the EVAPCP PID.

• Verify that the purge solenoid value releases vacuum while the 100% for the EVPCP PID.

• Is the purge solenoid valve operation normal?

• Perform the Variable Valve Timing Control System Operation Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [L5].)

• Is there any malfunction?

• Inspect the EGR valve. (See EGR VALVE INSPECTION [L5].)

• Is there any malfunction?

• Perform the “ENGINE COOLANT LEAKAGE INSPECTION”. (See ENGINE COOLANT LEAKAGE INSPECTION [L5].)

• Is there any malfunction?

• Inspect the engine compression. (See COMPRESSION INSPECTION [L5].)

• Is there any malfunction?

• Remove the PCV valve. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [L5].)

• Inspect the PCV valve. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE INSPECTION [L5].)

• Is there any malfunction?

• Replace the fuel, then go to the next step.

• Make sure to reconnect all disconnected connectors.

• Clear the DTC from the PCM memory using the M-MDS. (See AFTER REPAIR PROCEDURE [L5].)

• Perform the KOER self test. (See KOEO/KOER SELF TEST [L5].)

• Is the PENDING CODE for this DTC present?

• Perform the “AFTER REPAIR PROCEDURE”. (See AFTER REPAIR PROCEDURE [L5].)

• Are any DTCs present?