Code No. P0300: Random/Multiple Cylinder Misfire Detected <Vehicles for Hong kong>

OPERATION

Refer to Code No. P0201: No. 1 injector system .

Refer to Code No. P0202: No. 2 injector system .

Refer to Code No. P0203: No. 3 injector system .

Refer to Code No. P0204: No. 4 injector system .

FUNCTION

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

The engine-A/T-ECU checks for such changes in engine speed.

TROUBLE JUDGMENT

Check Conditions

Engine speed is 500 - 6,500 r/min.

Engine coolant temperature is -10°C or higher.

Barometric pressure is 76 kPa or higher.

Volumetric efficiency is between 30% and 55%.

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 Criteria (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

Misfire has occurred 15 times or more in the last 1,000 revolutions (that has been equivalent to approximately 1.5 times the emission standard).

PROBABLE CAUSE

Ignition system related part(s) failed

Failed crank angle sensor

Incorrect air-fuel ratio

Low compression pressure

Failed engine coolant temperature sensor

Skipping of timing belt teeth.

EGR system and EGR valve failed

Failed engine-A/T-ECU

DIAGNOSIS PROCEDURE

STEP 1.MUT-II/III data list

Item 22: Crank angle sensor

OK: Keep the engine speed constant to make the pulse width of output waveform constant.

Q: Is the check result normal?

YES: Go to Step 2

.
NO: Check crank angle sensor system (Refer to Code No. P0335

STEP 2. MUT-II/III data list

Refer to Data list reference table .

Item 21: Engine coolant temperature sensor

Item 81: Long-term fuel compensation

Item 82: Short-term fuel compensation

Q: Are the check results normal?

YES: Go to Step 3

.
NO: Perform the diagnosis code classified check procedure for the sensor that has shown an abnormal data valve (Refer to Inspection Chart for Diagnosis Code

STEP 3. Check ignition coil spark.

Q: Is the check result normal?

YES: Go to Step 4

.
NO: Check ignition circuit system (Refer to Inspection Procedure 31

STEP 4. Connector check: Injector connector

B-01 (No. 1 injector connector)

B-02 (No. 2 injector connector)

B-04 (No. 3 injector connector)

B-05 (No. 4 injector connector)

Q: Are the check results normal?

YES: Go to Step 5

.
NO: Repair.

STEP 5. Check injector itself.

Check Injector itself (Refer to ).

Q: Is the check result normal?

YES: Go to Step 6

.
NO: Replace injector.

STEP 6. Fuel pressure measurement.

Fuel pressure measurement (Refer to Fuel Pressure Test )

Q: Is the check result normal?

YES: Go to Step 7

.
NO: Repair.

STEP 7. Check for intake of air from intake hose and inlet manifold.

Q: Is the check result normal?

YES: Go to Step 8

.
NO: Repair.

STEP 8. Check for skipped timing belt teeth.

Q: Is the check result normal?

YES: Go to Step 9

.
NO: Repair.

STEP 9. Check EGR valve (stepper motor) itself.

Check EGR valve (stepper motor) itself [Refer to GROUP 17 - Exhaust Gas Recirculation (EGR) System - EGR Valve (Stepper Motor) Check <4G69> ].

Q: Is the check result normal?

YES: Go to Step 10

.
NO: Replace EGR valve (stepper motor)

STEP 10. Check the trouble symptoms.

Q: Does trouble symptom persist?

YES: Replace engine-A/T-ECU.
NO: Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points


Code No. P0300: Random/Multiple Cylinder Misfire Detected <Vehicles for Hong kong>

OPERATION Refer to Code No. P0201: No. 1 injector system . Refer to Code No. P0202: No. 2 injector system . Refer to Code No. P0203: No. 3 injector system . Refer to Code No. P0204: No. 4 injector system .
FUNCTION If a misfire occurs while the engine is running, the engine speed changes for an instant. The engine-A/T-ECU checks for such changes in engine speed.
TROUBLE JUDGMENT Check Conditions Engine speed is 500 - 6,500 r/min. Engine coolant temperature is -10°C or higher. Barometric pressure is 76 kPa or higher. Volumetric efficiency is between 30% and 55%. 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 Criteria (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 Misfire has occurred 15 times or more in the last 1,000 revolutions (that has been equivalent to approximately 1.5 times the emission standard).
PROBABLE CAUSE Ignition system related part(s) failed Failed crank angle sensor Incorrect air-fuel ratio Low compression pressure Failed engine coolant temperature sensor Skipping of timing belt teeth. EGR system and EGR valve failed Failed engine-A/T-ECU
	DIAGNOSIS PROCEDURE

	STEP 1.MUT-II/III data list Item 22: Crank angle sensor OK: Keep the engine speed constant to make the pulse width of output waveform constant. Q: Is the check result normal? YES: Go to Step 2 . NO: Check crank angle sensor system (Refer to Code No. P0335 ).
	STEP 2. MUT-II/III data list Refer to Data list reference table . Item 21: Engine coolant temperature sensor Item 81: Long-term fuel compensation Item 82: Short-term fuel compensation Q: Are the check results normal? YES: Go to Step 3 . NO: Perform the diagnosis code classified check procedure for the sensor that has shown an abnormal data valve (Refer to Inspection Chart for Diagnosis Code ).
	STEP 3. Check ignition coil spark. Q: Is the check result normal? YES: Go to Step 4 . NO: Check ignition circuit system (Refer to Inspection Procedure 31 ).
	STEP 4. Connector check: Injector connector
	B-01 (No. 1 injector connector) B-02 (No. 2 injector connector) B-04 (No. 3 injector connector) B-05 (No. 4 injector connector) Q: Are the check results normal? YES: Go to Step 5 . NO: Repair.
	STEP 5. Check injector itself. Check Injector itself (Refer to ). Q: Is the check result normal? YES: Go to Step 6 . NO: Replace injector.
	STEP 6. Fuel pressure measurement. Fuel pressure measurement (Refer to Fuel Pressure Test ) Q: Is the check result normal? YES: Go to Step 7 . NO: Repair.
	STEP 7. Check for intake of air from intake hose and inlet manifold. Q: Is the check result normal? YES: Go to Step 8 . NO: Repair.
	STEP 8. Check for skipped timing belt teeth. Q: Is the check result normal? YES: Go to Step 9 . NO: Repair.
	STEP 9. Check EGR valve (stepper motor) itself. Check EGR valve (stepper motor) itself [Refer to GROUP 17 - Exhaust Gas Recirculation (EGR) System - EGR Valve (Stepper Motor) Check <4G69> ]. Q: Is the check result normal? YES: Go to Step 10. NO: Replace EGR valve (stepper motor)
	STEP 10. Check the trouble symptoms. Q: Does trouble symptom persist? YES: Replace engine-A/T-ECU. NO: Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points ).