DTC P0300 / P0301 / P0302 / P0303 / P0304

DTC Detecting Condition and Trouble Area

DTC detecting condition	Trouble area
P0300: Random / Multiple Cylinder Misfire Detected Any of the following conditions is met. •Misfire, which causes catalyst to overheat during 200 engine revolutions, is detected at 2 or more cylinders. (MIL blinks as long as misfire lasts.) •Misfire, which affects exhaust emission adversely during 1,000 engine revolutions, is detected at 2 or more cylinders. (3 D/C detection logic)	•Exhaust system •Air intake system •Ignition system •Fuel system •Engine compression •Valve timing •ECM
P0301: Cylinder 1 Misfire Detected P0302: Cylinder 2 Misfire Detected P0303: Cylinder 3 Misfire Detected P0304: Cylinder 4 Misfire Detected Any of the following conditions is met. •Misfire, which causes catalyst to overheat during 200 engine revolutions, is detected at specific cylinder. (MIL blinks as long as misfire lasts.) •Misfire, which affects exhaust emission adversely during 1,000 engine revolutions, is detected at specific cylinder. (3 D/C detection logic)	•Ignition system •Engine compression •Fuel injector and/or its circuit •ECM

DTC detecting condition

Trouble area

P0300: Random / Multiple Cylinder Misfire Detected
Any of the following conditions is met.

•Misfire, which causes catalyst to overheat during 200 engine revolutions, is detected at 2 or more cylinders.
(MIL blinks as long as misfire lasts.)
•Misfire, which affects exhaust emission adversely during 1,000 engine revolutions, is detected at 2 or more cylinders.
(3 D/C detection logic)

•Exhaust system
•Air intake system
•Ignition system
•Fuel system
•Engine compression
•Valve timing
•ECM

P0301: Cylinder 1 Misfire Detected
P0302: Cylinder 2 Misfire Detected
P0303: Cylinder 3 Misfire Detected
P0304: Cylinder 4 Misfire Detected
Any of the following conditions is met.

•Misfire, which causes catalyst to overheat during 200 engine revolutions, is detected at specific cylinder.
(MIL blinks as long as misfire lasts.)
•Misfire, which affects exhaust emission adversely during 1,000 engine revolutions, is detected at specific cylinder.
(3 D/C detection logic)

•Ignition system
•Engine compression
•Fuel injector and/or its circuit
•ECM

DTC Confirmation Procedure

WARNING:

If you do not select a suitable route and take proper precautions when performing a road test, an accident can occur.

•Select a level road with no traffic to minimize the risk of accident.
•Perform the test extremely carefully.
•Perform the road test using 2 persons, a driver and a tester.

NOTE:

•Check that the following conditions are met in this “DTC Confirmation Procedure”.

—ECT > –10 °C (14 °F)
—Engine speed < 4,500 rpm

•Check that the following DTCs are not detected in this “DTC Confirmation Procedure”.

—CKP sensor (P0335 and P0336)

1)Warm up engine to normal operating temperature.

2)With engine speed at 4,500 rpm or less, drive vehicle at 50 to 80 km/h (31 to 50 mile/h) constantly for 5 min. or more.

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:K14C.
2	Fuel level check 1)Check fuel level by fuel level meter. Does it indicate “E” level (empty)?	Add fuel and recheck DTC.	Go to Step 3.
3	Fuel quality check 1)Check fuel in fuel tank for smell, color and quality. Is check result OK?	Go to Step 4.	Replace fuel with correct type fuel and recheck DTC.
4	Air intake system and exhaust system check 1)Check exhaust system and air intake system for clogging or leakage. Is check result OK?	Go to Step 5.	Repair or replace defective parts.
5	Ignition system check 1)Check ignition system. Is check result OK?	Go to Step 6.	Repair or replace defective parts.
6	Fuel system inspection 1)Check the following points related to fuel system. •Low fuel pressure: •High fuel pressure: •Fuel injector circuit: •Fuel injector: Is check result OK?	Go to Step 7.	Repair or replace defective parts.
7	Engine mechanical system check 1)Check the following points which can be cause of rough idling or poor performance. •Engine compression: •Valve timing: Is check result OK?	Check ECM power supply and ground circuits. If circuit is OK, replace ECM and recheck DTC.	Repair or replace defective parts.