SFI 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 hydrocarbons (HC) enter the exhaust gas. Extremely high hydrocarbon concentration levels can cause an increase in exhaust emission levels. Extremely high concentrations of hydrocarbons 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 count. 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 crank position sensor. The camshaft position sensor is used to identify any misfiring cylinders and the crank 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 stores a DTC.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Memory
P0300	Random / Multiple Cylinder Misfire Detected	Simultaneous misfiring of several cylinders occurs and one of the following conditions is met (2 trip detection logic). A misfire occurs that may damage the three-way catalytic converter (MIL blinks when detect immediately). An 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	Comes on / Blinks1 1: The MIL flashes when a catalyst damaging misfire is detected	DTC stored
P0301	Cylinder 1 Misfire Detected	Misfiring of a specific cylinder occurs and one of the following conditions is met (2 trip detection logic). A misfire occurs that may damage the three-way catalytic converter (MIL blinks when detect immediately). An 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	Comes on / Blinks1 1: The MIL flashes when a catalyst damaging misfire is detected	DTC stored
P0302	Cylinder 2 Misfire Detected	Misfiring of a specific cylinder occurs and one of the following conditions is met (2 trip detection logic). A misfire occurs that may damage the three-way catalytic converter (MIL blinks when detect immediately). An 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	Comes on / Blinks1 1: The MIL flashes when a catalyst damaging misfire is detected	DTC stored
P0303	Cylinder 3 Misfire Detected	Misfiring of a specific cylinder occurs and one of the following conditions is met (2 trip detection logic). A misfire occurs that may damage the three-way catalytic converter (MIL blinks when detect immediately). An 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	Comes on / Blinks1 1: The MIL flashes when a catalyst damaging misfire is detected	DTC stored
P0304	Cylinder 4 Misfire Detected	Misfiring of a specific cylinder occurs and one of the following conditions is met (2 trip detection logic). A misfire occurs that may damage the three-way catalytic converter (MIL blinks when detect immediately). An 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	Comes on / Blinks1 1: The MIL flashes when a catalyst damaging misfire is detected	DTC stored

When DTCs for misfiring cylinders are randomly 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 stores a DTC when either one of the following conditions, which could cause emission deterioration, is detected (2 trip detection logic).

An excessive number of misfires (approximately 50 to 80 misfires per 1000 crankshaft revolutions) occurs a total of 4 times.

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

At a high engine speed, a sufficient amount of misfires to damage the catalyst occurring within 200 crankshaft revolutions is detected once.
At a normal engine speed, a sufficient amount of misfires to damage the catalyst occurring within 200 crankshaft revolutions is detected 3 times.

MONITOR STRATEGY

Required Sensors/Components (Main)

Crank position sensor

Camshaft position sensor

Required Sensors/Components (Related)

Engine coolant temperature

Intake air temperature sensor

Mass air flow meter sub-assembly

Frequency of Operation

Continuous

TYPICAL ENABLING CONDITIONS

Misfire
Intake air temperature	Higher than -10°C (14°F)
Either of the following conditions is met	A or B
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 GTS to the DLC3.
Turn the power switch on (IG).
Turn the GTS on.
Record the DTC(s) and freeze frame data.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Put the engine in inspection mode (maintenance mode).

Click here
Using the GTS, switch the ECM from normal mode to check 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 so that the vehicle conditions displayed in Misfire RPM and Misfire Load of the Data List are the same as the freeze frame data. Perform this step several times.

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, confirm the Misfire RPM and Misfire Load in the Data List.

Engine speed	Duration
Idling	4.5 minutes or more
1000	4.5 minutes or more
2000	2.5 minutes or more
3000	1.5 minutes 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 output DTC(s) and freeze frame data have been recorded. When the ECM returns to normal mode (default), the stored DTC(s), freeze frame data and other data are cleared.
Record the DTC(s), 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 procedure).

WIRING DIAGRAM

Refer to DTC P0102 for the mass air flow meter sub-assembly circuit.

Click here

Refer to Fuel Injector Circuit.

Click here

CAUTION / NOTICE / HINT

Note

Inspect the fuses for circuits related to this system before performing the following procedure.

Tech Tips

If any DTCs other than misfire DTCs are output, troubleshoot those DTCs first.
Read freeze frame data using the GTS. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.
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 is considered to be a possible cause of the problem:

There was insufficient fuel in the tank.
Improper fuel was used.
The spark plugs have been contaminated.
The problem requires further diagnosis.

After finishing repairs, check the misfire counts of the cylinders (Cylinder #1 Misfire Count to Cylinder #4 Misfire Count).
Be sure to confirm that no misfiring cylinder DTCs are stored again by conducting the confirmation driving pattern after finishing repairs.
When one of Short FT #1 or 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 higher).
When Coolant Temp in the freeze frame data is below 75°C (167°F), the misfires have 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 GTS to the DLC3.
Turn the power switch on (IG).
Turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

Read the DTCs.

Click here

Powertrain > Engine and ECT > Trouble Codes

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 P0304 are output, troubleshoot those DTCs first.

GO TO DTC CHART Click here

CHECK PCV HOSE CONNECTIONS

Check the PCV hose connections.

Click here

OK
PCV valve and hose are correctly connected and are not damaged.

Result

Proceed to
OK
NG

REPAIR OR REPLACE PCV HOSE

READ VALUE USING GTS (MISFIRE RPM AND MISFIRE LOAD)

Connect the GTS to the DLC3.
Turn the power switch on (IG).
Turn the GTS on.

Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Misfire RPM and Misfire Load.

Powertrain > Engine and ECT > Data List

Tester Display
Misfire RPM
Misfire Load

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.

Result

Proceed to
NEXT

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

Connect the GTS to the DLC3.
Turn the power switch on (IG).
Turn the GTS on.
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.

Powertrain > Engine and ECT > Data List

Tester Display
Cylinder #1 Misfire Count
Cylinder #2 Misfire Count
Cylinder #3 Misfire Count
Cylinder #4 Misfire Count

Start the engine and allow the engine to idle.
Read each value for Cylinder #1 (to #4) Misfire Count displayed on the GTS. If no misfire counts occur in any cylinders, perform steps [A] and [B], and then check the misfire counts again.
Drive the vehicle with the Misfire RPM and Misfire Load noted in the read value using the GTS (Misfire RPM and Misfire Load) procedures above [A].

Read Cylinder #1 (to #4) Misfire Count or the DTCs displayed on the GTS [B].

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 less than 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

Inspect the spark plug of the misfiring cylinder.

Click here

Result

Proceed to
OK
NG

REPLACE SPARK PLUG Click here

CHECK FOR SPARK (SPARK TEST)

Perform a spark test.

Click here

Tech Tips

If the result of the spark test is normal, proceed to the next step.

Result

Proceed to
NEXT

CHECK CYLINDER COMPRESSION PRESSURE

Measure the cylinder compression pressure of the misfiring cylinder.

Click here

Result

Proceed to
OK
NG

CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION

CHECK TERMINAL VOLTAGE (#10, #20, #30 AND/OR #40)

*a	Front view of wire harness connector (to ECM)

Disconnect the ECM connector.
Turn the power switch on (IG).

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

Standard Voltage

Tester Connection	Condition	Specified Condition
B178-20 (#10) - B178-51 (E01)	Power switch on (IG)	11 to 14 V
B178-17 (#20) - B178-51 (E01)	Power switch on (IG)	11 to 14 V
B178-18 (#30) - B178-51 (E01)	Power switch on (IG)	11 to 14 V
B178-19 (#40) - B178-51 (E01)	Power switch on (IG)	11 to 14 V

Result

Proceed to
OK
NG

CHECK FUEL INJECTOR CIRCUIT Click here

CHECK FUEL INJECTOR ASSEMBLY

Check the fuel injector assembly injection (whether fuel volume is high or low, and whether injection pattern is poor).

Click here

Result

Proceed to
OK
NG

REPLACE FUEL INJECTOR ASSEMBLY Click here

CHECK INTAKE SYSTEM

Check the intake system for vacuum leaks.

Click here

OK
No leaks from intake system.

Result

Proceed to
OK
NG

REPAIR OR REPLACE INTAKE SYSTEM

CHECK FUEL PRESSURE

Check the fuel pressure.

Click here

Result

Proceed to
OK
NG

GO TO STEP 36 Click here

READ VALUE USING GTS (COOLANT TEMP)

Result

Proceed to
OK
NG

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

Powertrain > Engine and ECT > Data List

Tester Display

Coolant Temp

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

Standard

GTS 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)

Result

Proceed to
OK
NG

REPLACE ENGINE COOLANT TEMPERATURE SENSOR Click here

READ VALUE USING GTS (MAF)

Result

Proceed to
OK
NG

Connect the GTS to the DLC3.
Turn the power switch on (IG).
Turn the GTS on.
Put the engine in inspection mode (maintenance mode).

Click here

Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / MAF, Coolant Temp and Engine Speed.

Powertrain > Engine and ECT > Data List

Tester Display
Engine Speed
MAF
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.

Tech Tips

During charging control, the engine speed is set at idle. Therefore, the engine speed does not increase when depressing the accelerator pedal. In this case, read the Data List after charging control has completed.

Standard

GTS Display

Condition

Specified Condition

MAF

Shift position: N

A/C: Off

Engine Speed: 2500 rpm

Between 4.5 gm/sec and 8.5 gm/sec

Result

Proceed to
OK
NG

GO TO STEP 31 Click here

CHECK ENGINE MECHANICAL SYSTEM

Check for mechanical malfunctions that affect the valve timing, such as a jumped tooth or stretching of the timing chain.

Result

Proceed to
OK
NG

REPAIR OR REPLACE MALFUNCTIONING PARTS, COMPONENT AND AREA

CHECK WHETHER DTC OUTPUT RECURS (MISFIRE DTCS)

Connect the GTS to the DLC3.
Turn the power switch on (IG).
Turn the GTS on.
Clear the DTCs.

Click here

Powertrain > Engine and ECT > Clear DTCs
Turn the power switch off and wait for at least 30 seconds.
Turn the power switch on (IG).
Turn the GTS on.
Put the engine in inspection mode (maintenance mode).

Click here
Start the engine and warm it up.
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.

Powertrain > Engine and ECT > Utility

Tester Display

All Readiness
Input the DTC: P0300, P0301, P0302, P0303 or P0304.

Check the DTC judgment result.

Powertrain > Engine and ECT > Trouble Codes

Result

Proceed to

ABNORMAL

(DTC P0300, P0301, P0302, P0303 or P0304 is output)

NORMAL

(DTC is not output)

CHECK FOR INTERMITTENT PROBLEMS Click here

PERFORM ACTIVE TEST USING GTS (CONTROL THE EGR STEP POSITION)

Connect the GTS to the DLC3.
Turn the power switch on (IG).
Turn the GTS 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 / All Data / MAP and Throttle Idle Position.

Powertrain > Engine and ECT > Active Test

Active Test Display
Control the EGR Step Position

Data List Display
MAP
Throttle Idle Position

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

Note

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 maybe 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

GO TO STEP 31 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

Proceed to
OK
NG

GO TO STEP 31 Click here

REPLACE EGR VALVE ASSEMBLY Click here

CHECK INTAKE SYSTEM

Check the intake system for vacuum leaks.

Click here

OK
No leaks from intake system.

Result

Proceed to
OK
NG

REPAIR OR REPLACE INTAKE SYSTEM

CHECK FUEL PRESSURE

Check the fuel pressure.

Click here

Result

Proceed to
OK
NG

CHECK FUEL LINE Click here

READ VALUE USING GTS (COOLANT TEMP)

Result

Proceed to
OK
NG

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

Powertrain > Engine and ECT > Data List

Tester Display

Coolant Temp

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

Standard

GTS 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)

Result

Proceed to
OK
NG

REPLACE ENGINE COOLANT TEMPERATURE SENSOR Click here

READ VALUE USING GTS (MAF)

Result

Proceed to
OK
NG

Connect the GTS to the DLC3.
Turn the power switch on (IG).
Turn the GTS on.
Put the engine in inspection mode (maintenance mode).

Click here

Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / MAF, Coolant Temp and Engine Speed.

Powertrain > Engine and ECT > Data List

Tester Display
Engine Speed
MAF
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.

Tech Tips

Standard

GTS Display

Condition

Specified Condition

MAF

Shift position: N

A/C: Off

Engine Speed: 2500 rpm

Between 4.5 gm/sec and 8.5 gm/sec

Result

Proceed to
OK
NG

GO TO STEP 31 Click here

PERFORM ACTIVE TEST USING GTS (CONTROL THE EGR STEP POSITION)

Connect the GTS to the DLC3.
Turn the power switch on (IG).
Turn the GTS 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 / All Data / MAP and Throttle Idle Position.

Powertrain > Engine and ECT > Active Test

Active Test Display
Control the EGR Step Position

Data List Display
MAP
Throttle Idle Position

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

Note

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 maybe 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

GO TO STEP 24 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

Proceed to
OK
NG

REPLACE EGR VALVE ASSEMBLY Click here

INSPECT SPARK PLUG

Inspect the spark plug of the misfiring cylinder.

Click here

Result

Proceed to
OK
NG

REPLACE SPARK PLUG Click here

CHECK FOR SPARK (SPARK TEST)

Perform a spark test.

Click here

Tech Tips

If the result of the spark test is normal, proceed to the next step.

Result

Proceed to
NEXT

CHECK CYLINDER COMPRESSION PRESSURE

Measure the cylinder compression pressure of the misfiring cylinder.

Click here

Result

Proceed to
OK
NG

CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION

CHECK TERMINAL VOLTAGE (#10, #20, #30 AND/OR #40)

*a	Front view of wire harness connector (to ECM)

Disconnect the ECM connector.
Turn the power switch on (IG).

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

Standard Voltage

Tester Connection	Condition	Specified Condition
B178-20 (#10) - B178-51 (E01)	Power switch on (IG)	11 to 14 V
B178-17 (#20) - B178-51 (E01)	Power switch on (IG)	11 to 14 V
B178-18 (#30) - B178-51 (E01)	Power switch on (IG)	11 to 14 V
B178-19 (#40) - B178-51 (E01)	Power switch on (IG)	11 to 14 V

Result

Proceed to
OK
NG

CHECK FUEL INJECTOR CIRCUIT Click here

CHECK FUEL INJECTOR ASSEMBLY

Check the fuel injector assembly injection (whether fuel volume is high or low, and whether injection pattern is poor).

Click here

Result

Proceed to
OK
NG

REPLACE FUEL INJECTOR ASSEMBLY Click here

CHECK ENGINE MECHANICAL SYSTEM

Check for mechanical malfunctions that affect the valve timing, such as a jumped tooth or stretching of the timing chain.

Result

Proceed to
OK
NG

REPAIR OR REPLACE MALFUNCTIONING PARTS, COMPONENT AND AREA

CHECK WHETHER DTC OUTPUT RECURS (MISFIRE DTCS)

Connect the GTS to the DLC3.
Turn the power switch on (IG).
Turn the GTS on.
Clear the DTCs.

Click here

Powertrain > Engine and ECT > Clear DTCs
Turn the power switch off and wait for at least 30 seconds.
Turn the power switch on (IG).
Turn the GTS on.
Put the engine in inspection mode (maintenance mode).

Click here
Start the engine and warm it up.
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.

Powertrain > Engine and ECT > Utility

Tester Display

All Readiness
Input the DTC: P0300, P0301, P0302, P0303 or P0304.

Check the DTC judgment result.

Powertrain > Engine and ECT > Trouble Codes

Result

Proceed to

ABNORMAL

(DTC P0300, P0301, P0302, P0303 or P0304 is output)

NORMAL

(DTC is not output)

CHECK FOR INTERMITTENT PROBLEMS Click here

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

Check the connection and terminal contact pressure of connectors and wire harnesses between the mass air flow meter sub-assembly and ECM.

Click here

Tech Tips

Repair any problems.

Result

Proceed to
NEXT

CHECK WHETHER DTC OUTPUT RECURS (MISFIRE DTCS)

Connect the GTS to the DLC3.
Turn the power switch on (IG).
Turn the GTS on.
Clear the DTCs.

Click here

Powertrain > Engine and ECT > Clear DTCs
Turn the power switch off and wait for at least 30 seconds.
Turn the power switch on (IG).
Turn the GTS on.
Put the engine in inspection mode (maintenance mode).

Click here
Start the engine and warm it up.
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.

Powertrain > Engine and ECT > Utility

Tester Display

All Readiness
Input the DTC: P0300, P0301, P0302, P0303 or P0304.

Check the DTC judgment result.

Powertrain > Engine and ECT > Trouble Codes

Result

Proceed to

ABNORMAL

(DTC P0300, P0301, P0302, P0303 or P0304 is output)

NORMAL

(DTC is not output)

END

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

Result

Proceed to
OK
NG

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
B2-5 (VG) - B178-91 (VG)	Always	Below 1 Ω
B2-4 (E2G) - B178-92 (E2G)	Always	Below 1 Ω
B2-5 (VG) or B178-91 (VG) - Body ground	Always	10 kΩ or higher

Result

Proceed to
OK
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE MASS AIR FLOW METER SUB-ASSEMBLY

Replace the mass air flow meter sub-assembly.

Click here

Tech Tips

If the results of the inspections performed in steps 13 and 27 indicated no problem, proceed to the next step without replacing the mass air flow meter sub-assembly.

Result

Proceed to
NEXT

CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

Connect the GTS to the DLC3.
Turn the power switch on (IG).
Turn the GTS on.
Clear the DTCs.

Click here

Powertrain > Engine and ECT > Clear DTCs
Turn the power switch off and wait for at least 30 seconds.
Turn the power switch on (IG).
Turn the GTS on.
Put the engine in inspection mode (maintenance mode).

Click here
Start the engine and warm it up.
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.

Powertrain > Engine and ECT > Utility

Tester Display

All Readiness
Input the DTC: P0300, P0301, P0302, P0303 or P0304.

Check the DTC judgment result.

Powertrain > Engine and ECT > Trouble Codes

Result

Proceed to

NORMAL

(DTC is not output)

ABNORMAL

(DTC P0300, P0301, P0302, P0303 or P0304 is output)

END

REPLACE ECM Click here

CHECK FUEL LINE

Check the fuel lines for leaks or blockage.

Result

Proceed to
OK
NG

REPLACE FUEL PUMP Click here

REPAIR OR REPLACE FUEL LINE