Inspection steps

NOTE:

If any DTCs other than misfire-related DTCs are also recorded, repair the latter ones first.
Read the freeze frame data using the SSM4. A part of the engine running conditions under which the engine trouble occurred is recorded in the freeze frame data, which is useful for troubleshooting.
If the phenomenon cannot be confirmed, reproduce the conditions in the freeze frame data.
If either the [Short term fuel trim B1] or the [Long term fuel trim B1] of the freeze frame data are outside a ±20 % range, the air/fuel ratio may be rich (-20 % or less) or lean (+20 % or more).
If the [Coolant Temp.] of the freeze frame data is less than 80°C {176°F}, misfires may be occurring only when the engine is warmed up.
If the misfire cannot be reproduced, a lack of fuel, the use of an incorrect fuel, or dirt on the spark plug may be the cause.
Once repaired, check the values from [Cylinder #1 Misfire Count] to [Cylinder #4 Misfire Count].
If the wheel balance of the drive wheels is so off-balance that it causes body vibration, DTCs for misfires may be detected.
Once repaired, perform test drive to check that DTCs are not output.
By referring to following contents in the freeze frame data, you can estimate which cylinder was misfiring to what degree.
- [Cylinder #1 Misfire Count] to [Cylinder #4 Misfire Count] for each cylinder

Read DTC

Connect the SSM4 to the DLC3.
Turn the ignition switch to ON.
Follow the SSM4 on-screen instructions to check the DTCs. (Refer to CHECKING/CLEARING DTC )

RESULT DESCRIPTION

Result	Go to
P0300, P0301, P0302, P0303, or P0304 is output.	A
P0300, P0301, P0302, P0303, or P0304, and other DTCs are output.	B

NOTE: If any DTCs other than P0300, P0301, P0302, P0303, or P0304 are output, troubleshoot them first.

A: Go to next step

B: To corresponding DTC chart (Refer to DTC TABLE )

Inspection of the PCV hose
1. Check the PCV hose for poor connections and damage.
  Criteria: The PCV hose is properly connected and is not damaged.
NG: Repair or replacement of the PCV hose

OK: Go to next step

Inspection of the fuel injector ASSY (port injection side)

Select the following menu items using the SSM4.: [Each System]/[Engine Control System]/[Work Support]/[Active Test]/[Injection Mode Change]/[Port injection]
NOTE: The active test has restrictions.
Idle the engine.
Check the values of [Cylinder #1 Misfire Count] through [Cylinder #4 Misfire Count] in the data display while performing the active test.

RESULT DESCRIPTION

Active test Injection mode change	Data display [Cylinder #1 Misfire Count] to [Cylinder #4 Misfire Count]	Go to
Port injection	Misfiring occurs mainly in 1 or 2 cylinders	A
	Misfiring scatters across 3 or more cylinders	A
	Misfiring count is not output	B

A: Go to next step

B: Go to Step 14.

Inspection of the fuel injector ASSY (cylinder injection side)

Connect the SSM4 to the DLC3.
Select the following menu items using the SSM4.: [Each System]/[Engine Control System]/[Work Support]/[Active Test]/[Injection Mode Change]/[Cylinder injection]
NOTE: The active test has restrictions.
Idle the engine.
Check the values of [Cylinder #1 Misfire Count] through [Cylinder #4 Misfire Count] in the data display while performing the active test.

RESULT DESCRIPTION

Item name [Cylinder #1 Misfire Count] to [Cylinder #4 Misfire Count]		Go to
Port injection side	Direct injection side	Go to
Misfiring occurs mainly in 1 or 2 cylinders	Misfiring occurs mainly in 1 or 2 cylinders	A
Misfiring scatters across 3 or more cylinders	Misfiring scatters across 3 or more cylinders	B
Misfiring occurs mainly in 1 or 2 cylinders	Misfiring count is not output	C
Misfiring scatters across 3 or more cylinders	Misfiring count is not output	D

A: Go to next step

B: Go to Step 8.

C: Replacement of the fuel injector ASSY (port injection side) (Refer to REMOVAL )

D: Go to Step 12.

Spark plug inspection
1. Inspect the spark plug. (Refer to ON-VEHICLE INSPECTION )
NG: Spark plug replacement (Refer to REMOVAL )

OK: Go to next step
Spark Inspection
1. Perform the spark inspection. (Refer to ON-VEHICLE INSPECTION )
  NOTE: If no malfunction is found in the spark inspection, proceed to the next step.
Compression inspection
1. Inspect the compression. (Refer to ENGINE (FA20) , Step 8)
NG: Engine inspection to determine the cause of the low compression

OK: Go to next step

Replacement of the engine control computer (Refer to REMOVAL )
Intake system inspection
1. Inspect the intake system. (Refer to ON-VEHICLE INSPECTION )
NG: Repair or replacement of intake system

OK: Go to next step
PCV valve inspection
1. PCV valve inspection
2. Check deformation, cracks and other damages of the PCV valve.
NG: Repair or replace the PCV valve. (Refer to PCV VALVE (FA20) )

OK: Go to next step
PCV hose inspection
1. PCV hose inspection
2. Check deformation, cracks and other damages of the PCV hose.
NG: Repair or replace the PCV hose. (Refer to PCV VALVE (FA20) )

OK: Go to next step

Reading of SSM4 data ([Coolant Temp.])

Connect the SSM4 to the DLC3.
Select the following menu items using the SSM4.: [Each System]/[Engine Control System]/[Data monitor]/[Coolant Temp.]
Read [Coolant Temp.] both when the engine is cold and warmed up.

STANDARD VALUE SPECIFICATION

Item name	Inspection conditions	Standard value
[Coolant Temp.]	Cold start→After fully warmed up	Gradual increase
[Coolant Temp.]	After fully warmed up	75 to 100°C {167 to 212°F}

NG: Replacement of E.F.I. water temperature sensor (Refer to ENGINE COOLANT TEMPERATURE SENSOR (FA20) )

OK: Go to next step

Reading of SSM4 data ([Mass Air Flow])

Connect the SSM4 to the DLC3.
Turn the ignition switch to ON.
Turn ON the main switch of the SSM4.
Select the following menu items using the SSM4.: [Each System]/[Engine Control System]/[Data monitor]/[Mass Air Flow]
Read the [Mass Air Flow] displayed on the SSM4.

STANDARD VALUE SPECIFICATION

Item name	Inspection conditions	Standard value
[Mass Air Flow]	After the engine is warmed up, when running at 3000 r/min (Air conditioning OFF, shift lever in the N position)	8 to 13 g/s

NG: Go to Step 23.

OK: Go to next step

Valve timing inspection

Check the valve timing. (Refer to TIMING CHAIN (FA20) )

RESULT DESCRIPTION

Result	Go to
Malfunction	A
Normal	B

B: Go to Step 23.

A: Go to Step

Valve timing adjustment (Refer to ENGINE (FA20) )

Fuel pressure inspection (low-pressure side)
1. Check the fuel pressure (low-pressure side). (Refer to FUNCTION INSPECTION )
NG: Go to Step 13.

OK: Go to next step

Replacement of the fuel injector ASSY (port injection side) (Refer to REMOVAL )
Unit inspection of the fuel pump ASSY (low-pressure side)
1. Perform a unit inspection on the fuel pump (low-pressure side) (Refer to UNIT INSPECTION )
NG: Replacement of the fuel pump ASSY (low-pressure side) (Refer to REMOVAL )

OK: Go to next step

Check and replacement for the fuel system

Inspection of the fuel injector ASSY (cylinder injection side)

Connect the SSM4 to the DLC3.
Select the following menu items using the SSM4.: [Each System]/[Engine Control System]/[Work Support]/[Active Test]/[Injection Mode Change]/[Cylinder injection]
NOTE: The active test has restrictions.
Idle the engine.
Check the values of [Cylinder #1 Misfire Count] through [Cylinder #4 Misfire Count] in the data monitor while performing the active test.

RESULT DESCRIPTION

Item name [Cylinder #1 Misfire Count] to [Cylinder #4 Misfire Count]		Go to
Port injection side	Direct injection side	Go to
Misfiring count is not output	There is a misfiring count	A
Misfiring count is not output	Misfiring count is not output	B

A: Go to Step

B: Go to Step 15.

Replacement of fuel injector ASSY (direct injection side) (Refer to REMOVAL )

Reading of SSM4 data

Connect the SSM4 to the DLC3.
Select the following menu items using the SSM4.: [Each System]/[Engine Control System]/[Data monitor]/[Cylinder #1 Misfire Count], [Cylinder #2 Misfire Count], [Cylinder #3 Misfire Count], [Cylinder #4 Misfire Count], [Injection Mode(D4-S)]
Check the [Cylinder #1 Misfire Count] to [Cylinder #4 Misfire Count], and [Injection Mode(D4-S)] displayed on the SSM4.

RESULT DESCRIPTION

Item name		Go to
[Cylinder #1 Misfire Count] to [Cylinder #4 Misfire Count]	[Injection Mode(D4-S)]	Go to
Misfiring count is not output	-	A
Misfiring occurs mainly in 1 or 2 cylinders	[Port] or [Controlled injection]	B
Misfiring scatters across 3 or more cylinders	[Port] or [Controlled injection]	C
There is a misfiring count	[Cylinder injection]	D

A: Go to next step

B: Go to Step 16.

C: Go to Step 19.

D: Replacement of fuel injector ASSY (direct injection side) (Refer to REMOVAL )

Inspection for problems that do not normally occur (Refer to INSPECTION FOR PROBLEMS THAT DO NOT NORMALLY OCCUR )

Spark plug inspection
1. Inspect the spark plug. (Refer to ON-VEHICLE INSPECTION )
NG: Spark plug replacement (Refer to REMOVAL )

OK: Go to next step
Spark Inspection
1. Perform the spark inspection. (Refer to ON-VEHICLE INSPECTION )
  NOTE: If no malfunction is found in the spark inspection, proceed to the next step.
OK: Go to next step
Compression inspection
1. Inspect the compression. (Refer to ENGINE (FA20) )
NG: Engine inspection to determine the cause of the low compression

OK: Go to next step

Replacement of the engine control computer (Refer to REMOVAL )
Intake system inspection
1. Inspect the intake system. (Refer to ON-VEHICLE INSPECTION )
NG: Repair or replacement of intake system

OK: Go to next step

Reading of SSM4 data ([Coolant Temp.])

Connect the SSM4 to the DLC3.
Select the following menu items using the SSM4.: [Each System]/[Engine Control System]/[Data monitor]/[Coolant Temp.]
Read [Coolant Temp.] both when the engine is cold and warmed up.

STANDARD VALUE SPECIFICATION

Item name	Inspection conditions	Standard value
[Coolant Temp.]	Cold start →After fully warmed up	Gradual increase
[Coolant Temp.]	After fully warmed up	75 to 100°C {167 to 212°F}

NG: Replacement of E.F.I. water temperature sensor (Refer to ENGINE COOLANT TEMPERATURE SENSOR (FA20) )

OK: Go to next step

Reading of SSM4 data ([Mass Air Flow])

Connect the SSM4 to the DLC3.
Turn the ignition switch to ON.
Turn ON the main switch of the SSM4.
Select the following menu items using the SSM4.: [Each System]/[Engine Control System]/[Data monitor]/[Mass Air Flow]
Read the [Mass Air Flow] displayed on the SSM4.

STANDARD VALUE SPECIFICATION

Item name	Inspection conditions	Standard value
[Mass Air Flow]	After the engine is warmed up, when running at 3000 r/min (Air conditioning OFF, shift lever in the N position)	8 to 13 g/s

NG: Go to Step 23.

OK: Go to next step

Valve timing inspection
1. Check the valve timing. (Refer to TIMING CHAIN (FA20) )
NG: Valve timing adjustment (Refer to ENGINE (FA20) )

OK: Go to next step
Wiring harness and connector check
1. Check the connection state and fit of the wiring harnesses and connectors between the intake air flow meter SUB-ASSY and engine control computer. (Refer to INSPECTION PROCEDURES FOR ELECTRICAL CIRCUITS AND HOW TO PERFORM )
  NOTE: If there are poor connections or poor fits, replace or repair them.
Clear DTC
1. Connect the SSM4 to the DLC3.
2. Turn the ignition switch to ON, and follow the SSM4 on-screen display to clear the DTC. (Refer to CHECKING/CLEARING DTC )
3. Turn the ignition switch to OFF, and wait for 30 seconds.

Perform test drive for operation check

Start the engine, turn off all the accessory switches, and wait until the engine warms up and the coolant temperature stabilizes. (at 75°C {167°F} or more)
Perform test drive. (Refer to "TEST DRIVE " under "Description of functions")
WARNING: When performing this driving test, always observe the applicable traffic laws such as the speed limit.
Check the results.

RESULT DESCRIPTION

Result	Go to
Malfunction	A
Normal	B

A: Go to next step

B: Complete

Check wiring harness and connector (engine control computer - intake air flow meter SUB-ASSY)

NOTE: For the inspection procedure and precautions for wiring harnesses and connectors, refer to INSPECTION PROCEDURES FOR ELECTRICAL CIRCUITS AND HOW TO PERFORM .

Disconnect the connector for the engine control computer.
Disconnect the connector of the intake air flow meter SUB-ASSY.
Measure the resistance between the terminals. (For terminal arrangement, Refer to ECM TERMINAL ARRANGEMENT .)

STANDARD VALUE RESISTANCE SPECIFICATION (OPEN CIRCUIT CHECK)

Inspection terminals	Inspection conditions	Standard value
A33-22 (VG) - C16-5 (VG)	Always	Less than 1 Ω
A33-29 (E2G) - C16-4 (E2G)	Always	Less than 1 Ω

STANDARD VALUE RESISTANCE SPECIFICATION (SHORT CIRCUIT CHECK)

Inspection terminals	Inspection conditions	Standard value
A33-22 (VG) and C16-5 (VG) - other terminals and chassis ground	Always	10 k Ωor more
A33-29 (E2G) and C16-4 (E2G) - other terminals and chassis ground	Always	10 k Ωor more

NG: Repair or replacement of wiring harness or connector

OK: Go to next step

Replacement of the intake air flow meter SUB-ASSY
1. Replace the intake air flow meter SUB-ASSY. (Refer to INTAKE AIR FLOW METER S/A (FA20) )
  NOTE: If the results of the inspection from steps 10 and 21 are normal, proceed to the next step without replacing the intake air flow meter SUBASSY.
Clear DTC
1. Connect the SSM4 to the DLC3.
2. Turn the ignition switch to ON, and follow the SSM4 on-screen display to clear the DTC. (Refer to CHECKING/CLEARING DTC )
3. Turn the ignition switch to OFF, and wait for 30 seconds.

Perform test drive for operation check

Start the engine, turn off all the accessory switches, and wait until the engine warms up and the coolant temperature stabilizes. (at 75°C {167°F} or more)
Perform test drive. (Refer to "TEST DRIVE " under "Description of functions")
WARNING: When performing this driving test, always observe the applicable traffic laws such as the speed limit.
Check the results.

RESULT DESCRIPTION

Result	Go to
Normal	A
Malfunction	B

A: Go to next step

B: Replacement of the engine control computer (Refer to REMOVAL )

Complete