Code No. P0303: No. 3 Cylinder Misfire Detected <Vehicles except for Brazil>

OPERATION

Refer to Code No. P0203: No. 3 Injector System .

FUNCTION

If a misfire occurs while the engine is running, the engine speed changes for an instant.
The engine-ECU <M/T> or engine-A/T-ECU <A/T> checks for such changes in engine speed.

TROUBLE JUDGMENT

Check Conditions

Engine speed is 440 - 4,500 r/min.
Engine coolant temperature and intake air temperature are -10°C or higher.
Barometric pressure is 106 kPa or lower.
Volumetric efficiency is between 15 % and 100 %.
Adaptive learning is complete for the vane which generates a crankshaft position signal.
While the engine is running, excluding gear shifting, deceleration, sudden acceleration/deceleration and A/C compressor switching.
The throttle deviation is -0.06 V/10 ms to +0.06 V/10 ms.

Judgment Criterion (change in the angular acceleration of the crankshaft is used for misfire detection).

Misfire has occurred more frequently than the limit during the last 200 revolutions (when the catalyst temperature has been 950°C or higher).
or
The misfire ratio goes beyond the permitted limit within the first 1,000 revolutions from when the exhaust gas exceeds the regulation value.

PROBABLE CAUSES

Ignition system related part(s) failed
Low compression pressure
Failed engine-ECU <M/T> or engine-A/T-ECU <A/T>

DIAGNOSIS PROCEDURE

STEP 1. Visual check of ignition spark.

Remove the spark plug and install it to the ignition coil.
Connect the ignition coil connector.
Remove all injector connector.
At the engine start, check each spark plug produces a spark.

Q. Is the check result normal?

	Go to Step 3 .

	Go to Step 2 .

STEP 2. Check spark plug.

Check spark plug (Refer to GROUP 16 - Ignition System - On-vehicle Service - Spark Plug Check and Cleaning

Q. Is the check result normal?

	Check ignition circuit system (Refer to Inspection Procedure 26 ).

	Replace spark plug.

STEP 3. Connector check: B-120 No. 3 injector connector

Q. Is the check result normal?

	Go to Step 4 .

	Repair or replace the connector.

STEP 4. Check No. 3 injector itself.

Check Injector itself (Refer to ).

Q. Is the check result normal?

	Go to Step 5 .

	Replace the No. 3 injector.

STEP 5. Connector check: B-15X engine control relay connector and D-243 engine-ECU <M/T> connector or D-212 engine-A/T-ECU <A/T> connector

Q. Is the check result normal?

	Go to Step 6 .

	Repair or replace the connector.

STEP 6. Check harness between B-15X (terminal No. 1) engine control relay connector and B-120 (terminal No. 1) No. 3 injector connector.

note

Before checking harness, check intermediate connector B-28, and repair if necessary.

Check power supply line for damage.

Q. Is the check result normal?

	Go to Step 7 .

	Repair the damaged harness wire.

STEP 7. Check harness between B-120 (terminal No. 2) No. 3 injector connector and D-243 (terminal No. 14) engine-ECU <M/T> connector or D-212 (terminal No. 14) engine-A/T-ECU <A/T> connector

note

Before checking harness, check intermediate connector B-28, and repair if necessary.

Check output line for damage.

Q. Is the check result normal?

	Go to Step 8 .

	Repair the damaged harness wire.

STEP 8. Fuel pressure measurement.

Fuel pressure measurement (Refer to Fuel Pressure Test ).

Q. Is the check result normal?

	Go to Step 9 .

	Repair.

STEP 9. Check the trouble symptoms.

Q. Does trouble symptom persist?

	Replace the engine-ECU <M/T> or engine-A/T-ECU <A/T>.

	Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).