Part 2
2AR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0300-P0304: Random / Multiple Cylinder Misfire Detected
DTC P0300 - Random / Multiple Cylinder Misfire Detected
DTC P0301 - Cylinder 1 Misfire Detected
DTC P0302 - Cylinder 2 Misfire Detected
DTC P0303 - Cylinder 3 Misfire Detected
DTC P0304 - Cylinder 4 Misfire Detected
Continued
21. CHECK FUEL PRESSURE
(a) Check the fuel pressure Fuel System.
NG -- CHECK FUEL LINE
OK -- Continue to next step.
22. READ VALUE USING TECHSTREAM (COOLANT TEMP) P0171
NG -- REPLACE ENGINE COOLANT TEMPERATURE SENSOR Removal
OK -- Continue to next step.
23. READ VALUE USING MASS AIR FLOW METER (MAF) P0171
NG -- CHECK HARNESS AND CONNECTOR
OK -- Continue to next step.
24. CHECK VALVE TIMING P0011
NG -- ADJUST VALVE TIMING Installation
OK -- Continue to next step.
25. INSPECT SPARK PLUG
(a) Remove the ignition coil and spark plug from the misfiring cylinder.
(b) Measure the spark plug electrode gap.
Electrode gap for a new spark plug:
1.0 to 1.1 mm (0.039 to 0.043 in.)
Maximum electrode gap for a used spark plug:
1.3 mm (0.051 in.)
NOTICE:
If the electrode gap is more than 1.3 mm (0.051 in.), replace the spark plug. Do not adjust the electrode gap.
Recommended Spark Plug
(c) Check the electrode for carbon deposits.
NOTICE:
If necessary, clean the spark plug.
(d) Reinstall the ignition coil and spark plug.
NG -- REPLACE SPARK PLUG Removal
OK -- Continue to next step.
26. CHECK FOR SPARKS AND IGNITION
(a) Disconnect the injector connectors to prevent the engine from starting.
CAUTION:
Always disconnect all the injector connectors.
(b) Remove the ignition coil from the cylinder head.
(c) Install the spark plug onto the ignition coil.
(d) Attach the spark plug assembly to the cylinder head.
(e) Crank the engine for less than 2 seconds and check the spark.
NOTICE:
Do not crank the engine for more than 2 seconds.
OK:
Sparks jump across electrode gap.
(f) Install the ignition coil.
(g) Reconnect the injector connectors.
NG -- CHANGE TO NORMAL SPARK PLUG AND CHECK SPARK OF MISFIRING CYLINDER
OK -- Continue to next step.
27. CHECK CYLINDER COMPRESSION PRESSURE
(a) Measure the cylinder compression pressure of the misfiring cylinder Engine.
NG -- CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION
OK -- Continue to next step.
28. CHECK FUEL INJECTOR (POWER SOURCE) Fuel Injector Circuit
NG -- GO TO FUEL INJECTOR CIRCUIT Fuel Injector Circuit
OK -- Continue to next step.
29. CHECK HARNESS AND CONNECTOR (FUEL INJECTOR - ECM) Fuel Injector Circuit
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
30. CHECK FUEL INJECTOR OF MISFIRING CYLINDER
(a) Check the injector injection (whether fuel volume is high or low, and whether injection pattern is poor) Testing and Inspection.
NG -- REPLACE FUEL INJECTOR Removal
OK -- Continue to next step.
31. CHECK HARNESS AND CONNECTOR
(a) Check the connection and terminal contact pressure of connectors and wire harnesses between the mass air flow meter and ECM Electronic Circuit Inspection Procedure.
HINT
Repair any problems.
NEXT -- Continue to next step.
32. CHECK WHETHER DTC OUTPUT RECURS
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(e) Turn the ignition switch off.
(f) Turn the ignition switch to ON and turn the Techstream on.
(g) Start the engine and warm it up.
(h) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
(i) Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
(j) Input the DTC: P0300, P0301, P0302, P0303 or P0304.
(k) Check the DTC judgment result.
Result
B -- END
A -- Continue to next step.
33. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) P0171
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
34. REPLACE MASS AIR FLOW METER
(a) Replace the mass air flow meter assembly Removal.
HINT
If the results of the inspections performed in steps 17 and 23 indicated no problem, proceed to the next step without replacing the mass air flow meter assembly.
NEXT -- Continue to next step.
35. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(e) Turn the ignition switch off.
(f) Turn the ignition switch to ON and turn the Techstream on.
(g) Start the engine and warm it up.
(h) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
(i) Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
(j) Input the DTC: P0300, P0301, P0302, P0303 or P0304.
(k) Check the DTC judgment result.
Result
B -- REPLACE ECM Removal
A -- END
36. CHANGE TO NORMAL SPARK PLUG AND CHECK SPARK OF MISFIRING CYLINDER
(a) Change the installed spark plug to a spark plug that functions normally.
(b) Perform a spark test.
CAUTION:
Always disconnect all the injector connectors.
NOTICE:
Do not crank the engine for more than 2 seconds.
(1) Install the spark plug into the ignition coil and connect the ignition coil connector.
(2) Disconnect the injector connectors.
(3) Ground the spark plug.
(4) Check if sparks occur while the engine is being cranked.
OK:
Sparks jump across electrode gap.
NG -- CHANGE TO NORMAL IGNITION COIL AND CHECK SPARK OF MISFIRING CYLINDER
OK -- REPLACE SPARK PLUG Removal
37. CHANGE TO NORMAL IGNITION COIL AND CHECK SPARK OF MISFIRING CYLINDER
(a) Change the ignition coil to an ignition coil that functions normally.
(b) Perform a spark test.
CAUTION:
Always disconnect all the injector connectors.
NOTICE:
Do not crank the engine for more than 2 seconds.
(1) Install the spark plug into the ignition coil and connect the ignition coil connector.
(2) Disconnect the injector connectors.
(3) Ground the spark plug.
(4) Check if sparks occur while the engine is being cranked.
OK:
Sparks jump across electrode gap.
NG -- REPLACE ECM Removal
OK -- REPLACE IGNITION COIL Removal
38. CHECK FUEL LINE
(a) Check the fuel lines for leaks or blockage.
NG -- REPAIR OR REPLACE FUEL LINE
OK -- REPLACE FUEL PUMP Removal