Code No. P0302: No. 2 Cylinder Misfire Detected

OPERATION

Refer to Code No. P0202: No. 2 Injector System .

FUNCTION

If a misfire occurs while the engine is running, the engine speed changes for an instant.
The engine-ECU checks for such changes in engine speed.

TROUBLE JUDGMENT

Check Conditions

Engine speed is more than 440 r/min and is less than 4,500 r/min. <Except FFV>
Engine speed is more than 440 r/min and is less than 6,500 r/min. <FFV>
Engine coolant temperature is more than -10°C.
Barometric pressure is more than 76 kPa.
Volumetric efficiency is more than 20 % and is less than 40 %. <4B11>
Volumetric efficiency is more than 30 % and is less than 60 %. <4B12>
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.

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

Misfire has occurred more frequently than allowed during the last 200 revolutions (when the catalyst temperature is more than 1,000°C).

Misfire has occurred in more than 15 of the last 1,000 revolutions (corresponding to 1.5 times the limit of emission standard).

PROBABLE CAUSES

Ignition system related part(s) failed
Failed No. 2 injector
Harness damage in No. 2 injector circuit
Low compression pressure
Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. Visual check of ignition spark on No. 2 cylinder.

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

Q. Is the check result normal?

	Go to Step 2 .

	Check ignition circuit system (Refer to Inspection Procedure 22 )

STEP 2. Connector check: B-104 No. 2 injector connector

Q. Is the check result normal?

	Go to Step 3 .

	Repair or replace the connector.

STEP 3. Check No. 2 injector itself.

Check injector itself (Refer to Injector Check ).

Q. Is the check result normal?

	Go to Step 4 .

	Replace the No. 2 injector.

STEP 4. Connector check: A-24X injector relay connector

Q. Is the check result normal?

	Go to Step 5 .

	Repair or replace the connector.

STEP 5. Check harness between A-24X (terminal No. 3) injector relay connector and B-104 (terminal No. 1) No. 2 injector connector.

note

Before checking harness, check intermediate connector A-13, and repair if necessary.

Check power supply line for damage.

Q. Is the check result normal?

	Go to Step 6 .

	Repair the damaged harness wire.

STEP 6. Connector check: B-29 engine-ECU connector

Q. Is the check result normal?

	Go to Step 7 .

	Repair or replace the connector.

STEP 7. Check harness between B-104 (terminal No. 2) No. 2 injector connector and B-29 (terminal No. 3) engine-ECU connector.

Check output line for damage.

Q. Is the check result normal?

	Go to Step 8

	Repair the damaged harness wire.

STEP 8. Check compression pressure of No. 2 cylinder.

Check the compression pressure (Refer to GROUP 11I - On-vehicle Service - Compression Pressure Check <4B11>, Refer to GROUP 11E - On-vehicle Service - Compression Pressure Check <4B12>).

Q. Is the check result normal?

	Go to Step 9 .

	Repair.

STEP 9. M.U.T.-III diagnosis code.

Reconfirmation of diagnosis code

Q. Is diagnosis code set?

	Replace the engine-ECU.

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