P0305

DTC P0305: Cylinder 5 Misfire Detected

TECHNICAL DESCRIPTION

- If a misfire occurs while the engine is running, the engine speed changes for an instant.

- The ECM checks for such changes in engine speed.

DESCRIPTIONS OF MONITOR METHODS

Monitor angular acceleration of crankshaft and detect malfunction when negative variation of the angular acceleration is large.

MONITOR EXECUTION

Continuous

MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)

Other Monitor (There is no temporary DTC stored in memory for the item monitored below)

- Not applicable
Sensor (The sensor below is determined to be normal)

- Camshaft position sensor

- Mass airflow sensor

- Engine coolant temperature sensor

- Intake air temperature sensor

- Barometric pressure sensor

- Throttle position sensor

DTC SET CONDITIONS

Logic Flow Chart






Check Conditions

- Engine speed is between 438 and 6,500 r/min.

- Engine coolant temperature is higher than -10°C (14°F).

- Barometric pressure is higher than 76 kPa (22.4 in.Hg).

- The engine load is with in the positive torque load.

- Adaptive learning is complete for the vane which generates a crankshaft position signal.

- While the engine is running, excluding sudden acceleration/deceleration and fuel shut-off operation.
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 higher than 1,000°C (1,832°F)].
or

- The occurrence rate of engine misfiring within the 1,000 engine revolutions is more than 1.7 % [Except for California] or 1.8 % [California].

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 15 Monitors, Trips, Drive Cycles and Readiness Codes.

TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)

- Spark plug failed.

- Ignition system related part(s) failed.

- Low compression pressure.

- ECM failed.

DIAGNOSIS

STEP 1. Check the No. 5 cylinder ignition coil spark.

(1)Remove the intake manifold.

(2)Remove the No. 5 cylinder ignition coil.





(3)Remove the No. 5 cylinder spark plug and connect to the ignition coil.
(4)Ground the spark plug side electrode securely.

- When the engine is cranked, the spark plug should spark.

Q. Did it spark?

YES Go to Step 3.

NO Go to Step 2.

STEP 2. Check the No. 5 cylinder spark plugs.

Procedures.

Q. Is the spark plug normal?

YES Refer to INSPECTION PROCEDURE 24 - Ignition Circuit System Inspection Procedure 26.
NO Replace the No. 5 cylinder spark plug. Then go to Step 5.
STEP 3. Check the compression.

Testing and Inspection.

Q. Are there any abnormalities?

YES Replace it. Then go to Step 5.
NO Go to Step 4.
STEP 4. Check the trouble symptoms.

(1)Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 15 Monitors, Trips, Drive Cycles and Readiness Codes.

(2)Check the diagnostic trouble code (DTC).

Q. Is DTC P0305 set?

YES Replace the ECM. When the ECM is replaced, register the ID code. Refer to ID registration procedure manual - ID codes registration judgement table [Vehicles with KOS] or ID registration procedure manual - ID codes registration judgement table [Vehicles with WCM]. Then go to Step 5.
NO It can be assumed that this malfunction is intermittent. How to Cope With Intermittent Malfunctions.
STEP 5. Test the OBD-II drive cycle.

(1)Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 15 Monitors, Trips, Drive Cycles and Readiness Codes.

(2)Check the diagnostic trouble code (DTC).

Q. Is DTC P0305 set?

YES Retry the troubleshooting.
NO The inspection is complete.