SFI SYSTEM, Diagnostic DTC:P0300, P0301, P0302, P0303, P0304, P0305, P0306

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
P0305	Cylinder 5 Misfire Detected
P0306	Cylinder 6 Misfire Detected

DESCRIPTION

Text in Illustration
*1	VVT Sensor for Intake Side	*2	VVT Sensor for Exhaust Side
*3	Crankshaft Position Sensor (36-2 teeth)	*4	ECM

When the engine misfires, high concentrations of hydrocarbons (HC) enter the exhaust gas. Extremely high hydrocarbon concentration levels can cause increases in exhaust emission levels. 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 these increases 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 VVT sensor and crankshaft position sensor. The VVT 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 level and could cause emission deterioration, the ECM illuminates the MIL and stores a DTC.

DTC No.	DTC Detection Condition	Trouble Area
P0300	Simultaneous misfiring of several cylinders occurs and one of the following conditions 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 connections 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 ECM
P0301 P0302 P0303 P0304 P0305 P0306	Misfiring of specific cylinder occurs and one of the following conditions 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 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 connections
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
ECM

P0301

P0302

P0303

P0304

P0305

P0306

Misfiring of specific cylinder occurs and one of the following conditions 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 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.

WIRING DIAGRAM

for Automatic Transmission

for Manual Transmission

CONFIRMATION DRIVING PATTERN

Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Record the DTC(s) and freeze frame data.
Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Cylinder #1 (to #6) Misfire Count.
Read the misfire counts of each cylinder (Cylinder #1 (to #6) 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 Data List.

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

Engine Speed	Duration
Idling	8 minutes or more
1000	4.5 minutes or more
2000	2.5 minutes or more
3000	1.5 minutes or more

Enter the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.
Check whether misfires have occurred by checking pending DTCs and freeze frame data.

Tech Tips

Do not turn the engine 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 pending DTCs, freeze frame data and misfire counts.
Turn the engine switch off and wait for at least 5 seconds.

CAUTION / NOTICE / HINT

Tech Tips

Check the "Fuel Cut Elps Time" in the Data List or the Freeze Frame Data. If the elapsed time is over 0 seconds, then the engine speed is high (engine speed at which fuel cut occurs + 500 rpm). When this has happened, there is the possibility that the valve rocker arm will become loose and a fire could start, so check that the valve rocker arm is properly attached Click here.
By clearing the DTC, "Fuel Cut Elps Time" will be cleared.
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 may be a cause of the problem:

There was an insufficient amount of fuel in the tank.
Improper fuel is used.
The spark plugs have been contaminated.

After finishing repairs, check the misfire counts of the cylinders (Cylinder #1 Misfire Count to Cylinder #6 Misfire Count).
Be sure to confirm that no misfiring cylinder DTCs are stored again by conducting the confirmation driving pattern after finishing repairs.
For 6 cylinders engine, the ECM intentionally does not store the specific misfiring cylinder DTCs at high engine speeds. If misfires occur only at high engine speeds, only DTC P0300 is stored.

In the event of DTC P0300 being output, perform the following operations:

Clear the DTC Click here.
Start the engine and conduct the confirmation driving pattern.
Read the misfiring rates of each cylinder or the DTCs using the GTS.
Repair the cylinders that have a high misfiring rate or are indicated by the DTCs.
After finishing repairs, conduct the confirmation driving pattern again in order to verify that DTC P0300 is not stored.

When one of Short FT #1, Long FT #1, Short FT #2 or Long FT #2 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 below 75°C (167°F), the misfires have occurred only while the engine is being warmed up.
An extremely imbalanced drive wheel which causes body vibration may cause misfire DTCs to be stored.

PROCEDURE

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

Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

Read the DTCs.

Result
Result	Proceed to
DTC P0300, P0301, P0302, P0303, P0304, P0305 and/or P0306 are output	A
DTC P0300, P0301, P0302, P0303, P0304, P0305 and/or P0306 and other DTCs are output	B

Tech Tips

If any DTCs other than P0300, P0301, P0302, P0303, P0304, P0305 and/or P0306 are output, troubleshoot those DTCs first.

GO TO DTC CHART Click here

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

OK
READ VALUE USING GTS (MISFIRE RPM AND MISFIRE LOAD)
1. Connect the GTS to the DLC3.
2. Turn the engine switch on (IG).
3. Turn the GTS 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 GTS (CATALYST OT MF F/C)

Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Catalyst OT MF F/C.

Read the value displayed on the GTS.

Result
Data List	GTS Display	Proceed to
Catalyst OT MF F/C	Avail	A
Catalyst OT MF F/C	Not Avl	B

READ VALUE USING GTS (CYLINDER #1 (TO #6) MISFIRE COUNT) Click here

PERFORM ACTIVE TEST USING GTS
1. Connect the GTS to the DLC3.
2. Turn the engine switch on (IG).
3. Turn the GTS on.
4. Enter the following menus: Powertrain / Engine and ECT / Active Test / Prohibit the Catalyst OT Misfire prevent F/C.
5. Perform the Active Test.
  
  Note
  
  When performing the Active Test, make sure that the vehicle is stopped and either idling or being revved at 3000 rpm or less.
NEXT

READ VALUE USING GTS (CYLINDER #1 (TO #6) MISFIRE COUNT)

Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on (Step "A").
Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Cylinder #1 (to #6) Misfire Count (Step "B").
Read each value for Cylinder #1 (to #6) Misfire Count displayed on the GTS. If no misfire counts occur in any cylinders, perform the following procedure:
1. Start the engine and let it idle.
2. Move the shift lever to D.
3. Check the Cylinder #1 (to #6) Misfire Count.
4. If misfire counts are still not displayed, perform steps ("A") and ("B").
Drive the vehicle while satisfying the Misfire RPM and Misfire Load values noted in the "Read Value Using GTS (Misfire RPM and Misfire Load)" procedure above.

Read Cylinder #1 (to #6) Misfire Count or the DTCs displayed on the GTS.

Result
Misfire Count	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 Coolant Temp value of the freeze frame data is below 75°C (167°F), the misfire may be detected only when the engine is cold.
If the Engine Run Time value of the freeze frame data is below 120 seconds, the misfire may be detected immediately after the engine is started.

CHECK INTAKE SYSTEM Click here

CHECK SPARK PLUG

*1 1.3 mm

Remove the ignition coil assembly and the spark plug of the misfiring cylinder.
Measure the spark plug electrode gap.

Maximum gap

1.3 mm (0.0512 in.)

*1	1.3 mm

Maximum gap
1.3 mm (0.0512 in.)

Check the electrode for carbon deposits.

Recommended Spark Plug
Manufacturer	Product
DENSO	SK16HR11

Note

If the electrode gap is larger than the maximum, replace the spark plug. Do not adjust the electrode gap.

Reinstall the ignition coil assembly and spark plug.

Tech Tips
for Automatic Transmission
Perform "Inspection After Repair" after replacing the spark plug Click here.

REPLACE SPARK PLUG Click here

CHECK FOR SPARK (SPARK TEST)
1. Perform a spark test.
  
  CAUTION:
  
  During the test, disconnect all fuel injector assembly connectors.
  
  Note
  
  Do not crank the engine for more than 2 seconds.
  1. Remove the ignition coil assembly from the cylinder head.
  2. Install the spark plug to the ignition coil assembly.
  3. Disconnect the 6 fuel injector assembly connectors.
  4. Touch the spark plug to the cylinder head.
  5. Crank the engine for less than 2 seconds and check for a spark.
    
    OK
    
    Spark jumps across electrode gap.
  6. Reconnect the 6 fuel injector assembly connectors.
  7. Reinstall the ignition coil assembly.
NG
CHANGE TO KNOWN GOOD SPARK PLUG AND CHECK SPARK OF MISFIRING CYLINDER Click here

OK
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

OK
Spark jumps across electrode gap.

CHECK FUEL INJECTOR ASSEMBLY (POWER SOURCE)

Text in Illustration

*a
Front view of wire harness connector

(to Fuel Injector Assembly)

Disconnect the fuel injector assembly connectors.
Turn the engine 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
C1-1 - Body ground	Engine switch on (IG)	11 to 14 V
C2-1 - Body ground	Engine switch on (IG)	11 to 14 V
C3-1 - Body ground	Engine switch on (IG)	11 to 14 V
C4-1 - Body ground	Engine switch on (IG)	11 to 14 V
C5-1 - Body ground	Engine switch on (IG)	11 to 14 V
C6-1 - Body ground	Engine switch on (IG)	11 to 14 V

Reconnect the fuel injector assembly connectors.

CHECK 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 (Check for Open)

Tester Connection	Condition	Specified Condition
C1-2 - C37-6 (#10)	Always	Below 1 Ω
C2-2 - C37-1 (#20)	Always	Below 1 Ω
C3-2 - C37-7 (#30)	Always	Below 1 Ω
C4-2 - C37-2 (#40)	Always	Below 1 Ω
C5-2 - C37-8 (#50)	Always	Below 1 Ω
C6-2 - C37-3 (#60)	Always	Below 1 Ω

Standard Resistance (Check for Short)

Tester Connection	Condition	Specified Condition
C1-2 or C37-6 (#10) - Body ground	Always	10 kΩ or higher
C2-2 or C37-1 (#20) - Body ground	Always	10 kΩ or higher
C3-2 or C37-7 (#30) - Body ground	Always	10 kΩ or higher
C4-2 or C37-2 (#40) - Body ground	Always	10 kΩ or higher
C5-2 or C37-8 (#50) - Body ground	Always	10 kΩ or higher
C6-2 or C37-3 (#60) - Body ground	Always	10 kΩ or higher

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

REPAIR OR REPLACE HARNESS OR CONNECTOR (FUEL INJECTOR ASSEMBLY - ECM)

INSPECT ECM TERMINAL OF MISFIRING CYLINDER (#10, #20, #30, #40, #50 AND/OR #60 VOLTAGE)

Text in Illustration
*A	for Manual Transmission
*B	for Automatic Transmission
*a	Component with harness connected (ECM)

Turn the engine switch on (IG).

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

Standard Voltage

for Automatic Transmission
Tester Connection	Switch Condition	Specified Condition
C37-6 (#10) - C37-14 (E02)	Engine switch on (IG)	11 to 14 V
C37-1 (#20) - C37-14 (E02)	Engine switch on (IG)	11 to 14 V
C37-7 (#30) - C37-14 (E02)	Engine switch on (IG)	11 to 14 V
C37-2 (#40) - C37-14 (E02)	Engine switch on (IG)	11 to 14 V
C37-8 (#50) - C37-14 (E02)	Engine switch on (IG)	11 to 14 V
C37-3 (#60) - C37-14 (E02)	Engine switch on (IG)	11 to 14 V

for Manual Transmission
Tester Connection	Switch Condition	Specified Condition
C37-6 (#10) - C37-14 (E01)	Engine switch on (IG)	11 to 14 V
C37-1 (#20) - C37-14 (E01)	Engine switch on (IG)	11 to 14 V
C37-7 (#30) - C37-14 (E01)	Engine switch on (IG)	11 to 14 V
C37-2 (#40) - C37-14 (E01)	Engine switch on (IG)	11 to 14 V
C37-8 (#50) - C37-14 (E01)	Engine switch on (IG)	11 to 14 V
C37-3 (#60) - C37-14 (E01)	Engine switch on (IG)	11 to 14 V

Reconnect the ECM connector.

REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - BODY GROUND)

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.
  
  Tech Tips
  for Automatic Transmission
  Perform "Inspection After Repair" after replacing the fuel injector assembly Click here.
NG
REPLACE FUEL INJECTOR ASSEMBLY Click here

OK
INSPECT INTAKE SYSTEM
1. Check the intake system for vacuum leaks Click here.
  
  OK
  
  No leaks in intake system.
  
  Tech Tips
  for Automatic Transmission
  Perform "Inspection After Repair" after repairing or replacing the intake system Click here.
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 GTS (COOLANT TEMP)

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

Read the Coolant Temp twice when the engine is both cold and warmed up.

Standard
With cold engine
Same as ambient temperature.
With warm engine
Between 75°C and 95°C (167°F and 203°F).

Tech Tips

for Automatic Transmission

Perform "Inspection After Repair" after replacing the engine coolant temperature sensor Click here.

REPLACE ENGINE COOLANT TEMPERATURE SENSOR Click here

INSPECT MASS AIR FLOW METER
1. Inspect the mass air flow meter Click here.
  
  Tech Tips
  for Automatic Transmission
  Perform "Inspection After Repair" after replacing the mass air flow meter sub-assembly Click here.
NG
REPLACE MASS AIR FLOW METER Click here

OK
CHECK VALVE TIMING
1. Check the valve timing Click here.
OK
REPLACE ECM Click here

NG
CHECK ENGINE MECHANICAL SYSTEM Click here
CHECK INTAKE SYSTEM
1. Check the intake system for vacuum leaks Click here.
  
  OK
  
  No leaks in intake system.
  
  Tech Tips
  for Automatic Transmission
  Perform "Inspection After Repair" after repairing or replacing the intake system Click here.
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 GTS (COOLANT TEMP)

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

Read the Coolant Temp twice when the engine is both cold and warmed up.

Standard
With cold engine
Same as ambient air temperature.
With warm engine
Between 75°C and 95°C (167°F and 203°F).

Tech Tips

for Automatic Transmission

Perform "Inspection After Repair" after replacing the engine coolant temperature sensor Click here.

REPLACE ENGINE COOLANT TEMPERATURE SENSOR Click here

INSPECT MASS AIR FLOW METER
1. Inspect the mass air flow meter Click here.
  
  Tech Tips
  for Automatic Transmission
  Perform "Inspection After Repair" after replacing the mass air flow meter sub-assembly Click here.
NG
REPLACE MASS AIR FLOW METER Click here

OK
CHECK VALVE TIMING
1. Check the valve timing Click here.
NG
CHECK ENGINE MECHANICAL SYSTEM Click here

OK

CHECK SPARK PLUG

*1 1.3 mm

Remove the ignition coil assembly and the spark plug of the misfiring cylinder.
Measure the spark plug electrode gap.

Maximum gap

1.3 mm (0.0512 in.)

Check the electrode for carbon deposits.

Recommended Spark Plug
Manufacturer	Product
DENSO	SK16HR11

Note

If the electrode gap is larger than the maximum, replace the spark plug. Do not adjust the electrode gap.

Reinstall the ignition coil assembly and spark plug.

Tech Tips
for Automatic Transmission
Perform "Inspection After Repair" after replacing the spark plug Click here.

REPLACE SPARK PLUG Click here

CHECK FOR SPARK (SPARK TEST)
1. Perform a spark test.
  
  CAUTION:
  
  During the test, disconnect all fuel injector assembly connectors.
  
  Note
  
  Do not crank the engine for more than 2 seconds.
  1. Remove the ignition coil assembly from the cylinder head.
  2. Install the spark plug to the ignition coil assembly.
  3. Disconnect the 6 fuel injector assembly connectors.
  4. Touch the spark plug to the cylinder head.
  5. Crank the engine for less than 2 seconds and check for a spark.
    
    OK
    
    Spark jumps across electrode gap.
  6. Reconnect the 6 fuel injector assembly connectors.
  7. Reinstall the ignition coil assembly.
NG
CHANGE TO KNOWN GOOD SPARK PLUG AND CHECK SPARK OF MISFIRING CYLINDER Click here

OK
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)

Text in Illustration

*a
Front view of wire harness connector

(to Fuel Injector Assembly)

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

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

Standard Voltage

Tester Connection	Switch Condition	Specified Condition
C1-1 - Body ground	Engine switch on (IG)	11 to 14 V
C2-1 - Body ground	Engine switch on (IG)	11 to 14 V
C3-1 - Body ground	Engine switch on (IG)	11 to 14 V
C4-1 - Body ground	Engine switch on (IG)	11 to 14 V
C5-1 - Body ground	Engine switch on (IG)	11 to 14 V
C6-1 - Body ground	Engine switch on (IG)	11 to 14 V

Reconnect the fuel injector assembly connectors.

CHECK 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 (Check for Open)

Tester Connection	Condition	Specified Condition
C1-2 - C37-6 (#10)	Always	Below 1 Ω
C2-2 - C37-1 (#20)	Always	Below 1 Ω
C3-2 - C37-7 (#30)	Always	Below 1 Ω
C4-2 - C37-2 (#40)	Always	Below 1 Ω
C5-2 - C37-8 (#50)	Always	Below 1 Ω
C6-2 - C37-3 (#60)	Always	Below 1 Ω

Standard Resistance (Check for Short)

Tester Connection	Condition	Specified Condition
C1-2 or C37-6 (#10) - Body ground	Always	10 kΩ or higher
C2-2 or C37-1 (#20) - Body ground	Always	10 kΩ or higher
C3-2 or C37-7 (#30) - Body ground	Always	10 kΩ or higher
C4-2 or C37-2 (#40) - Body ground	Always	10 kΩ or higher
C5-2 or C37-8 (#50) - Body ground	Always	10 kΩ or higher
C6-2 or C37-3 (#60) - Body ground	Always	10 kΩ or higher

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

REPAIR OR REPLACE HARNESS OR CONNECTOR (FUEL INJECTOR ASSEMBLY - ECM)

INSPECT ECM TERMINAL OF MISFIRING CYLINDER (#10, #20, #30, #40, #50 AND/OR #60 VOLTAGE)

Text in Illustration
*A	for Manual Transmission
*B	for Automatic Transmission
*a	Component with harness connected (ECM)

Turn the engine switch on (IG).

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

Standard Voltage

for Automatic Transmission
Tester Connection	Switch Condition	Specified Condition
C37-6 (#10) - C37-14 (E02)	Engine switch on (IG)	11 to 14 V
C37-1 (#20) - C37-14 (E02)	Engine switch on (IG)	11 to 14 V
C37-7 (#30) - C37-14 (E02)	Engine switch on (IG)	11 to 14 V
C37-2 (#40) - C37-14 (E02)	Engine switch on (IG)	11 to 14 V
C37-8 (#50) - C37-14 (E02)	Engine switch on (IG)	11 to 14 V
C37-3 (#60) - C37-14 (E02)	Engine switch on (IG)	11 to 14 V

for Manual Transmission
Tester Connection	Switch Condition	Specified Condition
C37-6 (#10) - C37-14 (E01)	Engine switch on (IG)	11 to 14 V
C37-1 (#20) - C37-14 (E01)	Engine switch on (IG)	11 to 14 V
C37-7 (#30) - C37-14 (E01)	Engine switch on (IG)	11 to 14 V
C37-2 (#40) - C37-14 (E01)	Engine switch on (IG)	11 to 14 V
C37-8 (#50) - C37-14 (E01)	Engine switch on (IG)	11 to 14 V
C37-3 (#60) - C37-14 (E01)	Engine switch on (IG)	11 to 14 V

Reconnect the ECM connector.

REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - BODY GROUND)

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.
  
  Tech Tips
  for Automatic Transmission
  Perform "Inspection After Repair" after replacing the fuel injector assembly Click here.
OK
REPLACE ECM Click here

NG
REPLACE FUEL INJECTOR ASSEMBLY Click here
CHANGE TO KNOWN GOOD SPARK PLUG AND CHECK SPARK OF MISFIRING CYLINDER
1. Change the installed spark plug to a known good spark plug.
2. Perform a spark test.
  
  CAUTION:
  
  During the test, disconnect all fuel injector assembly connectors.
  
  Note
  
  Do not crank the engine for more than 2 seconds.
  1. Remove the ignition coil assembly from the cylinder head.
  2. Install the spark plug to the ignition coil assembly.
  3. Disconnect the 6 fuel injector assembly connectors.
  4. Touch the spark plug to the cylinder head.
  5. Crank the engine for less than 2 seconds and check for a spark.
    
    OK
    
    Spark jumps across electrode gap.
  6. Reconnect the 6 fuel injector assembly connectors.
  7. Reinstall the ignition coil assembly.
  Tech Tips
  for Automatic Transmission
  Perform "Inspection After Repair" after replacing the spark plug Click here.
OK
REPLACE SPARK PLUG Click here

NG
CHANGE TO KNOWN GOOD IGNITION COIL ASSEMBLY AND CHECK SPARK OF MISFIRING CYLINDER
1. Change the installed ignition coil assembly to a known good ignition coil assembly.
2. Perform a spark test.
  
  CAUTION:
  
  During the test, disconnect all fuel injector assembly connectors.
  
  Note
  
  Do not crank the engine for more than 2 seconds.
  1. Remove the ignition coil assembly from the cylinder head.
  2. Install the spark plug onto the ignition coil assembly.
  3. Disconnect the 6 fuel injector assembly connectors.
  4. Touch the spark plug to the cylinder head.
  5. Crank the engine for less than 2 seconds and check for spark.
    
    OK
    
    Spark jumps across electrode gap.
  6. Reconnect the 6 fuel injector assembly connectors.
  7. Reinstall the ignition coil assembly.
  Tech Tips
  for Automatic Transmission
  Perform "Inspection After Repair" after replacing the ignition coil assembly Click here.
OK
REPLACE IGNITION COIL ASSEMBLY Click here

NG
REPLACE ECM Click here

CHECK FUEL LINE

Check the fuel lines for leaks or blockage.

Result
Result	Proceed to
NG	A
OK (for Single Tank Type)	B
OK (for Double Tank Type)	C

Tech Tips

for Automatic Transmission

Perform "Inspection After Repair" after replacing the fuel pump Click here.

REPAIR OR REPLACE FUEL LINE

REPLACE FUEL PUMP Click here