SFI SYSTEM(w/ EGR System), Diagnostic DTC:P0300, P0301, P0302, P0303, P0304

DTC Code	DTC Name
P0300	Random / Multiple Cylinder Misfire Detected
P0301	Cylinder 1 Misfire Detected
P0302	Cylinder 2 Misfire Detected
P0303	Cylinder 3 Misfire Detected
P0304	Cylinder 4 Misfire Detected

DESCRIPTION

When the engine misfires, high concentrations of hydrocarbon (HC) enter the exhaust gas. High HC concentration levels can cause an increase in exhaust emission levels. Extremely high concentrations of HC can also cause increases in the three-way catalytic converter temperature, which may cause damage to the three-way catalytic converter. To prevent this increase in emissions and to limit the possibility of thermal damage, the ECM monitors the misfire rate. When the temperature of the three-way catalytic converter reaches the point of thermal degradation, the ECM blinks the MIL. To monitor misfires, the ECM uses both the camshaft position sensor and the crankshaft position sensor. The camshaft position sensor is used to identify any misfiring cylinders and the crankshaft position sensor is used to measure variations in the crankshaft rotation speed. Misfires are counted when the crankshaft rotation speed variations exceed predetermined thresholds. If the misfire count exceeds the threshold levels, and could cause emission control system performance deterioration, the ECM illuminates the MIL and sets a DTC.

DTC No.	DTC Detection Condition	Trouble Area
P0300	Simultaneous misfiring of several cylinders occurs and one of the following conditions below is detected (2 trip detection logic): High temperature misfire occurs in three-way catalytic converter (MIL blinks when detect immediately) Emission deterioration misfire occurs (MIL illuminates)	Open or short in engine wire harness Connector connection Vacuum hose connections Ignition system Fuel injector assembly Fuel pressure Mass air flow meter sub-assembly Engine coolant temperature sensor Compression pressure Valve timing PCV valve and hose PCV hose connections Intake system EGR valve assembly ECM
P0301 P0302 P0303 P0304	Misfiring of a specific cylinder occurs and one of the following conditions below is detected (2 trip detection logic): High temperature misfire occurs in three-way catalytic converter (MIL blinks when detect immediately) Emission deterioration misfire occurs (MIL illuminates)

DTC No.

DTC Detection Condition

Trouble Area

P0300

Simultaneous misfiring of several cylinders occurs and one of the following conditions below is detected (2 trip detection logic):

High temperature misfire occurs in three-way catalytic converter (MIL blinks when detect immediately)
Emission deterioration misfire occurs (MIL illuminates)

Open or short in engine wire harness
Connector connection
Vacuum hose connections
Ignition system
Fuel injector assembly
Fuel pressure
Mass air flow meter sub-assembly
Engine coolant temperature sensor
Compression pressure
Valve timing
PCV valve and hose
PCV hose connections
Intake system
EGR valve assembly
ECM

P0301

P0302

P0303

P0304

Misfiring of a specific cylinder occurs and one of the following conditions below is detected (2 trip detection logic):

High temperature misfire occurs in three-way catalytic converter (MIL blinks when detect immediately)
Emission deterioration misfire occurs (MIL illuminates)

When multiple DTCs for misfiring cylinders are stored, but DTC P0300 is not stored, it indicates that misfires have been detected in different cylinders at different times. DTC P0300 is only stored when several misfiring cylinders are detected at the same time.

MONITOR DESCRIPTION

The ECM illuminates the MIL and sets a DTC when the following conditions, which could cause emission control system performance deterioration, is detected (2 trip detection logic).

An excessive misfiring rate (approximately 20 to 50 misfires per 1000 crankshaft revolutions) occurs a total of 4 times.

The ECM flashes the MIL (immediate detection logic) and sets a DTC (2 trip detection logic) when either one of the following conditions, which could cause the three-way catalytic converter damage, is detected.

Tech Tips

If a catalyst damage misfire occurs, the monitor informs the driver by blinking the MIL (1 trip).

A sufficient amount of misfire to damage the catalyst occurring within 200 crankshaft revolutions is detected 3 times.

MONITOR STRATEGY

Required Sensors/Components (Main)

Crankshaft position sensor

Camshaft position sensor

Required Sensors/Components (Related)

Engine coolant temperature sensor

Intake air temperature sensor

Mass air flow meter sub-assembly

Frequency of Operation

Continuous

TYPICAL ENABLING CONDITIONS

Misfire
Either of the following conditions (a) or (b) is met	-
(a) Engine coolant temperature at engine start	Higher than -7°C (19°F)
(b) Engine coolant temperature	Higher than 20°C (68°F)

Monitor Period of Emission-Related Misfire
Duration	Crankshaft 1000 revolutions x 4

Monitor Period of Catalyst Damaging Misfire (MIL Blinks)
Duration	Crankshaft 200 revolutions x 3

CONFIRMATION DRIVING PATTERN

Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Turn the tester on.
Record the DTC(s) and freeze frame data.
Switch the ECM from normal mode to check mode Click here.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC operation).
Put the engine in inspection mode (maintenance mode) Click here.
Read the misfire counts of each cylinder, Cylinder #1 Misfire Count to Cylinder #4 Misfire Count, with the engine idling. If any misfire count is displayed, skip the following confirmation driving pattern.

Drive the vehicle several times with the conditions, such as engine speed and engine load, as shown in Misfire RPM and Misfire Load in the freeze frame data.

Tech Tips

In order to store misfire DTCs, it is necessary to operate the vehicle for the period of time shown in the table below with the engine speed and engine load the same as Misfire RPM and Misfire Load in the freeze frame data.

Engine Speed	Duration
Idling	4 minutes or more
1000	4 minutes and 30 seconds or more
2000	2 minutes and 30 seconds or more
3000	1 minute and 30 seconds or more

Check whether misfires have occurred by checking DTCs and freeze frame data.

Tech Tips

Do not turn the power switch off until the stored DTCs and freeze frame data have been recorded. When the ECM returns to normal mode (default), the stored DTCs, freeze frame data and other data will be cleared.
Record the DTCs, freeze frame data and misfire counts.
Turn the power switch off and wait for at least 30 seconds.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC operation).

WIRING DIAGRAM

Fuel injector circuit: Refer to Fuel Injector Circuit Click here.

Mass air flow meter sub-assembly circuit: Refer to DTC P0102 Click here.

CAUTION / NOTICE / HINT

Tech Tips

If any DTCs other than misfire DTCs are output, troubleshoot those DTCs first.
Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.
If the misfire does not recur when the vehicle is brought to the workshop, reproduce the conditions stored in the ECM as freeze frame data.
If the misfire still cannot be reproduced even though the conditions stored in the ECM as freeze frame data have been reproduced, one of the following factors may be a cause of the problem:

The fuel level is low.
Improper fuel is being used.
The spark plugs are dirty.

After finishing repairs, check that no misfires occur in each cylinder (Cylinder No. 1, No. 2, No. 3 and No. 4).
Be sure to confirm that no misfiring cylinder DTCs are stored again by conducting the confirmation driving pattern after the repairs.
When one of Short FT #1or Long FT #1 in the freeze frame data is outside the range of +/-20%, the air fuel ratio may be Rich (-20% or less) or Lean (+20% or more).
When the Coolant Temp in the freeze frame data is less than 75°C (167°F), the misfire has occurred only while warming up the engine.
An extremely imbalanced drive wheel which causes body vibration may cause misfire DTCs to be stored.

PROCEDURE

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO MISFIRE DTCS)

Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Turn the tester on.
Enter the following menus: Powertrain / Engine and ECT / DTC.

Read the DTCs.

Result
Result	Proceed to
DTC P0300, P0301, P0302, P0303 and/or P0304 are output	A
DTC P0300, P0301, P0302, P0303 and/or P0304 and other DTCs are output	B

Tech Tips

If any DTCs other than P0300, P0301, P0302, P0303 and/or P0304 are output, troubleshoot those DTCs first.

GO TO DTC CHART Click here

CHECK PCV HOSE CONNECTIONS
1. Check the PCV hose connections Click here.
  
  OK
  
  PCV hose is connected correctly and is not damaged.
NG
REPAIR OR REPLACE PCV HOSE

OK
READ VALUE USING INTELLIGENT TESTER (MISFIRE RPM AND MISFIRE LOAD)
1. Connect the intelligent tester to the DLC3.
2. Turn the power switch on (IG).
3. Turn the tester on.
4. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Misfire RPM and Misfire Load.
5. Read and note the Misfire RPM and Misfire Load values.
  
  Tech Tips
  
  The Misfire RPM and Misfire Load values indicate the vehicle conditions under which the misfire occurred.
NEXT

OK
PCV hose is connected correctly and is not damaged.

READ VALUE USING INTELLIGENT TESTER (CYLINDER #1 (TO #4) MISFIRE COUNT)

Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Turn the tester on.
Clear the DTCs Click here.
Put the engine in inspection mode (maintenance mode) Click here.
Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Cylinder #1 (to #4) Misfire Count.
Start the engine and allow the engine to idle.
Read each value for Cylinder #1 Misfire Count to Cylinder #4 Misfire Count displayed on the tester. If no misfire counts occur in any cylinders, perform steps (i) and (j) and then check the misfire counts again.
Drive the vehicle with the Misfire RPM and Misfire Load noted in the "Read Value Using Intelligent Tester (Misfire Rpm And Misfire Load)" procedures above.

Read the Cylinder #1 Misfire Count to Cylinder #4 Misfire Count or DTCs displayed on the tester.

Result
Result	Proceed to
Most misfires occur in only 1 or 2 cylinders	A
3 cylinders or more have equal misfire counts	B

Tech Tips

If it is difficult to reproduce misfires for each cylinder, check the Data List item called Misfire Margin. Try to find vehicle driving conditions that lower the Misfire Margin value. Values above 30% are considered normal.
If the freeze frame data record of the engine coolant temperature is below 75°C (167°F), it may only be possible to detect the misfire when the engine is cold.

CHECK INTAKE SYSTEM Click here

INSPECT SPARK PLUG
1. Inspect the spark plug of the misfiring cylinder Click here.
NG
REPLACE SPARK PLUG Click here

OK
CHECK FOR SPARK (SPARK TEST)
1. Perform a spark test Click here.
  
  Tech Tips
  
  If the result of the spark test is normal, proceed to the next step.
NEXT
CHECK CYLINDER COMPRESSION PRESSURE OF MISFIRING CYLINDER
1. Measure the cylinder compression pressure of the misfiring cylinder Click here.
NG
CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION

OK

CHECK FUEL INJECTOR ASSEMBLY (POWER SOURCE VOLTAGE)

Text in Illustration

*a
Front view of wire harness connector

(to Fuel Injector Assembly)

Disconnect the fuel injector assembly connectors.
Turn the power switch on (IG).

Text in Illustration
*a	Front view of wire harness connector (to Fuel Injector Assembly)

Measure the voltage according to the value(s) in the table below.

Standard Voltage

Tester Connection	Switch Condition	Specified Condition
D14-1 - Body ground	Power switch on (IG)	11 to 14 V
D15-1 - Body ground	Power switch on (IG)	11 to 14 V
D16-1 - Body ground	Power switch on (IG)	11 to 14 V
D17-1 - Body ground	Power switch on (IG)	11 to 14 V

GO TO FUEL INJECTOR CIRCUIT Click here

CHECK HARNESS AND CONNECTOR (FUEL INJECTOR ASSEMBLY - ECM)

Disconnect the fuel injector assembly connectors.
Disconnect the ECM connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance

Tester Connection	Condition	Specified Condition
D14-2 - D27-85 (#10)	Always	Below 1 Ω
D15-2 - D27-84 (#20)	Always	Below 1 Ω
D16-2 - D27-83 (#30)	Always	Below 1 Ω
D17-2 - D27-82 (#40)	Always	Below 1 Ω
D14-2 or D27-85 (#10) - Body ground	Always	10 Ω or higher
D15-2 or D27-84 (#20) - Body ground	Always	10 Ω or higher
D16-2 or D27-83 (#30) - Body ground	Always	10 Ω or higher
D17-2 or D27-82 (#40) - Body ground	Always	10 Ω or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

CHECK FUEL INJECTOR ASSEMBLY OF MISFIRING CYLINDER
1. Check the fuel injector assembly injection (whether fuel volume is high or low, and whether injection pattern is poor) Click here.
NG
REPLACE FUEL INJECTOR ASSEMBLY Click here

OK
CHECK INTAKE SYSTEM
1. Check the intake system for vacuum leaks Click here.
  
  OK
  
  No leaks in intake system.
NG
REPAIR OR REPLACE INTAKE SYSTEM

OK
CHECK FUEL PRESSURE
1. Check the fuel pressure Click here.
NG
CHECK FUEL LINE Click here

OK

OK
No leaks in intake system.

READ VALUE USING INTELLIGENT TESTER (COOLANT TEMP)

Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Turn the tester on.
Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.

Read the Data List twice, when the engine is both cold and warmed up.

Standard
Tester Display	Condition	Specified Condition
Coolant Temp	Cold engine	Same as ambient air temperature
Coolant Temp	Warm engine	Between 75 and 100°C (167 and 212°F)

REPLACE ENGINE COOLANT TEMPERATURE SENSOR Click here

READ VALUE USING INTELLIGENT TESTER (MAF)

Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Turn the tester on.
Put the engine in inspection mode (maintenance mode) Click here.
Start the engine.
Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / MAF and Coolant Temp.
Allow the engine to idle until Coolant Temp reaches 75°C (167°F) or higher.

Read MAF with the engine speed at 2500 rpm.

Standard
Tester Display	Condition	Specified Condition
MAF	Shift lever position: P Engine Speed: 2500 rpm	Between 4.5 gm/sec. and 8.5 gm/sec.

CHECK HARNESS AND CONNECTOR Click here

ADJUST VALVE TIMING

Tech Tips

There are no marks on the cylinder head to match-up for the purpose of checking valve timing. Valve timing can only be inspected by lining up the colored plates on the timing chain with the marks on the pulleys. It may be necessary to remove and reinstall the chain to match-up the alignment marks Click here.

Text in Illustration
*a	Top
*b	Alignment Mark
*c	No. 1 Cylinder at TDC Compression

CHECK WHETHER DTC OUTPUT RECURS (P0300, P0301, P0302, P0303 OR P0304)

Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Turn the tester on.
Clear the DTCs Click here.
Turn the power switch off and wait for at least 30 seconds.
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
Input the DTC: P0300, P0301, P0302, P0303 or P0304.

Check the DTC judgment result.

Result
Result	Proceed to
ABNORMAL (DTC P0300, P0301, P0302, P0303 or P0304 is output)	A
NORMAL (DTC is not output)	B

END

PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE EGR STEP POSITION)

Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Turn the tester on.
Put the engine in inspection mode (maintenance mode) Click here.
Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or more.

Tech Tips

The A/C switch and all accessory switches should be off.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position / Data List / All Data / Throttle Idle Position and MAP.

Confirm that the Throttle Idle Position is ON and check the MAP value in the Data List while performing the Active Test.

Tech Tips

Do not leave the EGR valve open for 10 seconds or more during the Active Test.
Be sure to return the EGR valve to step 0 when the Active Test is completed.
Do not open the EGR valve 30 steps or more during the Active Test.

OK
MAP change in response to EGR step position when Throttle Idle Position is ON in Data List.

Standard

EGR Step Position (Active Test)

0 Steps

0 to 30 Steps

MAP

(Data List)

(EGR valve is fully closed)

MAP value is at least +10 kPa (75 mmHg) higher than when EGR valve is fully closed

Tech Tips

While performing the Active Test, if the increase in the value of MAP is small, the EGR valve assembly may be a malfunctioning.
Even if the EGR valve assembly is malfunctioning, rough idling or an increase in the value of MAP may occur while performing the Active Test. However, the amount that the value of MAP increases will be smaller than normal.

Result
Result	Proceed to
Outside of standard range	A
Within standard range	B

CHECK HARNESS AND CONNECTOR Click here

INSPECT EGR VALVE ASSEMBLY

Remove the EGR valve assembly Click here.

Check if the EGR valve is stuck open.

OK
EGR valve is tightly closed.

Result
Result	Proceed to
NG	A
OK	B

REPLACE EGR VALVE ASSEMBLY Click here

CHECK HARNESS AND CONNECTOR Click here

CHECK INTAKE SYSTEM
1. Check the intake system for vacuum leaks Click here.
  
  OK
  
  No leaks in intake system.
NG
REPAIR OR REPLACE INTAKE SYSTEM

OK
CHECK FUEL PRESSURE
1. Check the fuel pressure Click here.
NG
CHECK FUEL LINE Click here

OK

READ VALUE USING INTELLIGENT TESTER (COOLANT TEMP)

Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Turn the tester on.
Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.

Read the Data List twice, when the engine is both cold and warmed up.

Standard
Tester Display	Condition	Specified Condition
Coolant Temp	Cold engine	Same as ambient air temperature
Coolant Temp	Warm engine	Between 75 and 100°C (167 and 212°F)

REPLACE ENGINE COOLANT TEMPERATURE SENSOR Click here

READ VALUE USING INTELLIGENT TESTER (MAF)

Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Turn the tester on.
Put the engine in inspection mode (maintenance mode) Click here.
Start the engine.
Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / MAF and Coolant Temp.
Allow the engine to idle until Coolant Temp reaches 75°C (167°F) or higher.

Read MAF with the engine speed at 2500 rpm.

Standard
Tester Display	Condition	Specified Condition
MAF	Shift lever position: P Engine Speed: 2500 rpm	Between 4.5 gm/sec. and 8.5 gm/sec.

CHECK HARNESS AND CONNECTOR Click here

PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE EGR STEP POSITION)

Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Turn the tester on.
Put the engine in inspection mode (maintenance mode) Click here.
Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.

Tech Tips

The A/C switch and all accessory switches should be off.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position / Data List / All Data / Throttle Idle Position and MAP.

Confirm that the Throttle Idle Position is ON and check the MAP value in the Data List while performing the Active Test.

Tech Tips

Do not leave the EGR valve open for 10 seconds or more during the Active Test.
Be sure to return the EGR valve to step 0 when the Active Test is completed.
Do not open the EGR valve 30 steps or more during the Active Test.

OK
MAP change in response to EGR step position when Throttle Idle Position is ON in Data List.

Standard

EGR Step Position (Active Test)

0 Steps

0 to 30 Steps

MAP

(Data List)

(EGR valve is fully closed)

MAP value is at least +10 kPa (75 mmHg) higher than when EGR valve is fully closed

Tech Tips

While performing the Active Test, if the increase in the value of MAP is small, the EGR valve assembly may be a malfunctioning.
Even if the EGR valve assembly is malfunctioning, rough idling or an increase in the value of MAP may occur while performing the Active Test. However, the amount that the value of MAP increases will be smaller than normal.

Result
Result	Proceed to
Outside of standard range	A
Within standard range	B

INSPECT SPARK PLUG Click here

INSPECT EGR VALVE ASSEMBLY
1. Remove the EGR valve assembly Click here.
2. Check if the EGR valve is stuck open.
  
  OK
  
  EGR valve is tightly closed.
NG
REPLACE EGR VALVE ASSEMBLY Click here

OK
INSPECT SPARK PLUG
1. Inspect the spark plug of the misfiring cylinder Click here.
NG
REPLACE SPARK PLUG Click here

OK
CHECK FOR SPARK (SPARK TEST)
1. Perform a spark test Click here.
  
  Tech Tips
  
  If the result of the spark test is normal, proceed to the next step.
NEXT
CHECK CYLINDER COMPRESSION PRESSURE OF MISFIRING CYLINDER
1. Measure the cylinder compression pressure of the misfiring cylinder Click here.
NG
CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION

OK

CHECK FUEL INJECTOR ASSEMBLY (POWER SOURCE VOLTAGE)

Text in Illustration

*a
Front view of wire harness connector

(to Fuel Injector Assembly)

Disconnect the fuel injector assembly connectors.
Turn the power switch on (IG).

Measure the voltage according to the value(s) in the table below.

Standard Voltage

Tester Connection	Switch Condition	Specified Condition
D14-1 - Body ground	Power switch on (IG)	11 to 14 V
D15-1 - Body ground	Power switch on (IG)	11 to 14 V
D16-1 - Body ground	Power switch on (IG)	11 to 14 V
D17-1 - Body ground	Power switch on (IG)	11 to 14 V

GO TO FUEL INJECTOR CIRCUIT Click here

CHECK HARNESS AND CONNECTOR (FUEL INJECTOR ASSEMBLY - ECM)

Disconnect the fuel injector assembly connectors.
Disconnect the ECM connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance

Tester Connection	Condition	Specified Condition
D14-2 - D27-85 (#10)	Always	Below 1 Ω
D15-2 - D27-84 (#20)	Always	Below 1 Ω
D16-2 - D27-83 (#30)	Always	Below 1 Ω
D17-2 - D27-82 (#40)	Always	Below 1 Ω
D14-2 or D27-85 (#10) - Body ground	Always	10 Ω or higher
D15-2 or D27-84 (#20) - Body ground	Always	10 Ω or higher
D16-2 or D27-83 (#30) - Body ground	Always	10 Ω or higher
D17-2 or D27-82 (#40) - Body ground	Always	10 Ω or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

CHECK FUEL INJECTOR ASSEMBLY OF MISFIRING CYLINDER
1. Check the fuel injector assembly injection (whether fuel volume is high or low, and whether injection pattern is poor) Click here.
NG
REPLACE FUEL INJECTOR ASSEMBLY Click here

OK

ADJUST VALVE TIMING

Tech Tips

Text in Illustration
*a	Top
*b	Alignment Mark
*c	No. 1 Cylinder at TDC Compression

CHECK WHETHER DTC OUTPUT RECURS (DTC P0300, P0301, P0302, P0303 OR P0304)

Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Turn the tester on.
Clear the DTCs Click here.
Turn the power switch off and wait for at least 30 seconds.
Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
Input the DTC: P0300, P0301, P0302, P0303 or P0304.

Check the DTC judgment result.

Result
Result	Proceed to
ABNORMAL (DTC P0300, P0301, P0302, P0303 or P0304 is output)	A
NORMAL (DTC is not output)	B

END

CHECK HARNESS AND CONNECTOR
1. Check the connection and terminal contact pressure of the connectors and wire harness between the mass air flow meter sub-assembly and ECM Click here.
  
  Tech Tips
  
  Repair any problems.
NEXT

CHECK DTC OUTPUT RECURS (DTC P0300, P0301, P0302, P0303 OR P0304)

Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Turn the tester on.
Clear the DTCs Click here.
Turn the power switch off and wait for at least 30 seconds.
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
Input the DTC: P0300, P0301, P0302, P0303 or P0304.

Check the DTC judgment result.

Result
Result	Proceed to
ABNORMAL (DTC P0300, P0301, P0302, P0303 or P0304 is output)	A
NORMAL (DTC is not output)	B

END

CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM)

Disconnect the mass air flow meter sub-assembly connector.
Disconnect the ECM connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance

Tester Connection	Condition	Specified Condition
D5-5 (VG) - D27-94 (VG)	Always	Below 1 Ω
D5-4 (E2G) - D27-117 (E2G)	Always	Below 1 Ω
D5-5 (VG) or D27-94 (VG) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE MASS AIR FLOW METER SUB-ASSEMBLY
1. Replace the mass air flow meter sub-assembly Click here.
  
  Tech Tips
  
  If the result of the inspection performed in steps 14 and 22 indicated no problem, proceed to the next step without replacing the mass air flow meter sub-assembly.
NEXT

CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Turn the tester on.
Clear the DTCs Click here.
Turn the power switch off and wait for at least 30 seconds.
Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
Input the DTC: P0300, P0301, P0302, P0303 or P0304.

Check the DTC judgment result.

Result
Result	Proceed to
ABNORMAL (DTC P0300, P0301, P0302, P0303 or P0304 is output)	A
NORMAL (DTC is not output)	B

REPLACE ECM Click here

END

CHECK FUEL LINE
1. Check the fuel lines for leaks or blockage.
OK
REPLACE FUEL PUMP Click here

NG
REPAIR OR REPLACE FUEL LINE