1A
DTC P0300 / P0301 / P0302 / P0303 / P0304: Random Misfire Detected / Cylinder 1 / Cylinder 2 / Cylinder 3 / Cylinder 4 Misfire Detected
System Description
ECM measure the angle of the crankshaft based on the pulse signal from the CKP sensor and CMP sensor for each cylinder. If it detects a large change in the angle speed of the crankshaft, it concludes occurrence of a misfire. When the number of misfire is counted by ECM beyond the DTC detecting condition, it determine the cylinder where the misfire occurred and output it as DTC.
DTC Detecting Condition and Trouble Area
DTC detecting condition Trouble area
DTC P0300:
• Misfire, which causes catalyst to overheat during 200 engine revolutions, is detected at 2 or more cylinders. (MIL flashes as long as this misfire occurs continuously.)
or
• Misfire, which affects exhaust emission adversely during 1000 engine revolution, is detected at 2 or more cylinders. (2 driving cycle detection logic)
• Ignition system
• Fuel injector and its circuit
• Fuel pressure
• EGR system
• Abnormal air drawn in
• Engine compression
• Valve lash adjuster
• Valve timing
• Fuel shortage
DTC P0301, P0302, P0303, P0304:
• Misfire, which causes catalyst to overheat during 200 engine revolutions, is detected at 1 cylinder. (MIL flashes as long as this misfire occurs continuously.)
or
• Misfire, which affects exhaust emission adversely during 1000 engine revolution, is detected at 1 cylinder. (2 driving cycle detection logic)
DTC Confirmation Procedure
WARNING:
• When performing a road test, select a place where there is no traffic or possibility of a traffic accident and be very careful during testing to avoid occurrence of an accident.
• Road test should be carried out with 2 persons, a driver and a tester, on a level road.
NOTE:
Check to make sure that the following conditions are satisfied when using this “DTC Confirmation Procedure”.
• Intake air temp.: –7 °C, 19.4 °F or higher
• Engine coolant temp.: –10 °C, 14 °F or higher
• Altitude (barometric pressure): 2500 m, 8200 ft or less (540 mmHg, 72 kPa or more)
1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Drive vehicle under freeze frame data condition as noted for 1 min. or more.
4) Stop vehicle and check DTC and pending DTC.
DTC Troubleshooting
Step Action YES NO
1
Was “Engine and Emission Control System Check” performed?
Go to Step 2.
Go to Engine and Emission Control System Check:M13A with VVT .
2
Does fuel level meter indicate “E” level (empty)?
Add fuel and recheck.
Go to Step 3.
3
Ignition system check
1) Check spark plug and ignition spark of cylinder where misfire occurs, referring to Spark Plug Inspection:M13A and Ignition Spark Test:M13A .
Are they in good condition?
Go to Step 4.
Faulty ignition coil, wire harness, spark plug or other system parts.
4
Fuel injector circuit check
1) Using sound scope, check each injector operating sound at engine cranking or idling.
Do all injectors make operating sound?
Go to Step 5.
Check coupler connection and wire harness of injector not making operating sound and injector itself. If OK, substitute a known-good ECM and recheck.
5
Fuel pressure check
1) Check fuel pressure referring to Fuel Pressure Inspection:M13A .
Is check result satisfactory?
Go to Step 6.
Repair or replace.
6
Fuel injector check
1) Check fuel injector(s) referring to Fuel Injector Inspection:M13A .
Is check result satisfactory?
Go to Step 7.
Replace.
7
Ignition timing check
1) Check ignition timing referring to Ignition Timing Inspection:M13A .
Is check result satisfactory?
Go to Step 8.
Check related sensors.
8
EGR system check
1) Check EGR system referring to EGR System Inspection (If Equipped):M13A .
Is check result satisfactory?
Go to Step 9.
Repair or replace.
9
Engine mechanical system check
1) Check engine mechanical parts or system which can cause engine rough idle or poor performance.
• Engine compression (Refer to Compression Check:M13A .)
• Valve lash (Refer to Valve Lash (Clearance) Inspection:M13A .)
• Valve timing (Refer to Timing Chain and Chain Tensioner Removal and Installation:M13A .)
Are they in good condition?
Check wire harness and connection of ECM ground, ignition system and fuel injector for intermittent open and short.
Repair or replace.
NOTE:
Upon completion of inspection and repair work, perform “DTC Confirmation Procedure” and confirm that the trouble has been corrected.