P0300, P0301, P0302, P0303, P0304 MISFIRE
EC-855
< COMPONENT DIAGNOSIS >[MR18DE]
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
P0300, P0301, P0302, P0303, P0304 MISFIRE
DTC LogicINFOID:0000000001161823
DTC DETECTION LOGIC
When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the crank-
shaft position (CKP) sensor (POS) signal to vary, ECM can determine that a misfire is occurring.
The misfire detection logic consists of the following two conditions.
1. One Trip Detection Logic (Three Way Catalyst Damage)
On the 1st trip that a misfire condition occurs that can damage the three way catalyst (TWC) due to over-
heating, the MI will blink.
When a misfire condition occurs, the ECM monitors the CKP sensor signal every 200 engine revolutions
for a change.
When the misfire condition decreases to a level that will not damage the TWC, the MI will turn off.
If another misfire condition occurs that can damage the TWC on a second trip, the MI will blink.
When the misfire condition decreases to a level that will not damage the TWC, the MI will remain on.
If another misfire condition occurs that can damage the TWC, the MI will begin to blink again.
2. Two Trip Detection Logic (Exhaust quality deterioration)
For misfire conditions that will not damage the TWC (but will affect vehicle emissions), the MI will only light
when the misfire is detected on a second trip. During this condition, the ECM monitors the CKP sensor
signal every 1,000 engine revolutions.
A misfire malfunction can be detected on any one cylinder or on multiple cylinders.
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE-I
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Restart engine and let it idle for about 15 minutes.
4. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-856, "Diagnosis Procedure".
NO >> GO TO 3.
3.PERFORM DTC CONFIRMATION PROCEDURE-II
1. Turn ignition switch OFF and wait at least 10 seconds.
Sensor Input signal to ECM ECM function
Crankshaft position sensor (POS) Engine speed On board diagnosis of misfire
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0300 Multiple cylinder misfire detected Multiple cylinder misfire. Improper spark plug
Insufficient compression
Incorrect fuel pressure
The fuel injector circuit is open or shorted
Fuel injector
Intake air leak
The ignition signal circuit is open or shorted
Lack of fuel
Signal plate
Heated oxygen sensor 1
Incorrect PCV hose connection P0301 No.1 cylinder misfire detected No. 1 cylinder misfires.
P0302 No. 2 cylinder misfire detected No. 2 cylinder misfires.
P0303 No. 3 cylinder misfire detected No. 3 cylinder misfires.
P0304 No. 4 cylinder misfire detected No. 4 cylinder misfires.
P0300, P0301, P0302, P0303, P0304 MISFIRE
EC-857
< COMPONENT DIAGNOSIS >[MR18DE]
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
2. Listen to each fuel injector operating sound.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Perform trouble diagnosis for FUEL INJECTOR, refer to
EC-976, "
Component Inspection".
5.CHECK FUNCTION OF IGNITION COIL-I
CAUTION:
Do the following procedure in the place where ventilation is good without the combustible.
1. Turn ignition switch OFF.
2. Remove fuel pump fuse in IPDM E/R to release fuel pressure.
NOTE:
Do not use CONSULT-III to release fuel pressure, or fuel pressure applies again during the following pro-
cedure.
3. Start engine.
4. After engine stalls, crank it two or three times to release all fuel pressure.
5. Turn ignition switch OFF.
6. Remove all ignition coil harness connectors to avoid the electrical discharge from the ignition coils.
7. Remove ignition coil and spark plug of the cylinder to be checked.
8. Crank engine for 5 seconds or more to remove combustion gas in the cylinder.
9. Connect spark plug and harness connector to ignition coil.
10. Fix ignition coil using a rope etc. with gap of 13 - 17 mm (0.52 -
0.66 in) between the edge of the spark plug and grounded metal
portion as shown in the figure.
11. Crank engine for about 3 seconds, and check whether spark is
generated between the spark plug and the grounded metal por-
tion.
CAUTION:
Do not approach to the spark plug and the ignition coil
within 50 cm (19.7 in). Be careful not to get an electrical
shock while checking, because the electrical discharge
voltage becomes 20kV or more.
It might cause to damage the ignition coil if the gap of more than 17 mm (0.66 in) is taken.
NOTE:
When the gap is less than 13 mm (0.52 in), the spark might be generated even if the coil is mal-
functioning.
Is the inspection result normal?
YES >> GO TO 9.
NO >> GO TO 6.
6.CHECK FUNCTION OF IGNITION COIL-II
1. Turn ignition switch OFF.
2. Disconnect spark plug and connect a known-good spark plug.
3. Crank engine for about 3 seconds, and recheck whether spark is generated between the spark plug and
the grounded metal portion.
Is the inspection result normal?
YES >> GO TO 7.
NO >> Check ignition coil, power transistor and their circuits. Refer to EC-981, "
Component Function
Check". Clicking noise should be heard.
PBIB3332E
Spark should be generated.
JMBIA0066GB
Spark should be generated.
EC-858
< COMPONENT DIAGNOSIS >[MR18DE]
P0300, P0301, P0302, P0303, P0304 MISFIRE
7.CHECK SPARK PLUG
Check the initial spark plug for fouling, etc.
Is the inspection result normal?
YES >> Replace spark plug(s) with standard type one(s). For
spark plug type, refer to EM-145, "
Removal and Installa-
tion".
NO >> Repair or clean spark plug. Then GO TO 8.
8.CHECK FUNCTION OF IGNITION COIL-III
1. Reconnect the initial spark plugs.
2. Crank engine for about 3 seconds, and recheck whether spark is generated between the spark plug and
the grounded portion.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace spark plug(s) with standard type one(s). For spark plug type, refer to EM-145, "
Removal
and Installation".
9.CHECK COMPRESSION PRESSURE
Check compression pressure. Refer to EM-151, "
Checking Compression Pressure".
Is the inspection result normal?
YES >> GO TO 10.
NO >> Check pistons, piston rings, valves, valve seats and cylinder head gaskets.
10.CHECK FUEL PRESSURE
1. Install all removed parts.
2. Check fuel pressure. Refer to EC-1035, "
Inspection".
Is the inspection result normal?
YES >> GO TO 12.
NO >> GO TO 11.
11 .DETECT MALFUNCTIONING PART
Check fuel hoses and fuel tubes for clogging.
Is the inspection result normal?
YES >> Replace “fuel filter and fuel pump assembly”.
NO >> Repair or replace.
12.CHECK IGNITION TIMING
For procedure, refer to EC-689, "
BASIC INSPECTION : Special Repair Requirement".
For specification, refer to EC-1038, "
Idle Speed" and EC-1038, "Ignition Timing".
Is the inspection result normal?
YES >> GO TO 13.
NO >> Follow the EC-693, "
IGNITION TIMING : Special Repair Requirement".
13.CHECK HEATED OXYGEN SENSOR 1 HEATER
Refer to EC-829, "
Component Inspection".
Is the inspection result normal?
YES >> GO TO 14.
NO >> Replace heated oxygen sensor 1.
SEF156I
Spark should be generated.
P0420 THREE WAY CATALYST FUNCTION
EC-873
< COMPONENT DIAGNOSIS >[MR18DE]
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
Is the inspection result normal?
YES >> GO TO 6.
NO >> Perform EC-975, "
Diagnosis Procedure".
6.CHECK FUNCTION OF IGNITION COIL-I
CAUTION:
Do the following procedure in the place where ventilation is good without the combustible.
1. Turn ignition switch OFF.
2. Remove fuel pump fuse in IPDM E/R to release fuel pressure.
NOTE:
Do not use CONSULT-III to release fuel pressure, or fuel pressure applies again during the following pro-
cedure.
3. Start engine.
4. After engine stalls, crank it two or three times to release all fuel pressure.
5. Turn ignition switch OFF.
6. Remove all ignition coil harness connectors to avoid the electrical discharge from the ignition coils.
7. Remove ignition coil and spark plug of the cylinder to be checked.
8. Crank engine for 5 seconds or more to remove combustion gas in the cylinder.
9. Connect spark plug and harness connector to ignition coil.
10. Fix ignition coil using a rope etc. with gap of 13 - 17 mm (0.52 -
0.66 in) between the edge of the spark plug and grounded metal
portion as shown in the figure.
11. Crank engine for about 3 seconds, and check whether spark is
generated between the spark plug and the grounded metal por-
tion.
CAUTION:
Do not approach to the spark plug and the ignition coil
within 50 cm (19.7 in). Be careful not to get an electrical
shock while checking, because the electrical discharge
voltage becomes 20kV or more.
It might cause to damage the ignition coil if the gap of more than 17 mm (0.66 in) is taken.
NOTE:
When the gap is less than 13 mm (0.52 in), the spark might be generated even if the coil is mal-
functioning.
Is the inspection result normal?
YES >> GO TO 10.
NO >> GO TO 7.
7.CHECK FUNCTION OF IGNITION COIL-II
1. Turn ignition switch OFF.
2. Disconnect spark plug and connect a known-good spark plug.
3. Crank engine for about 3 seconds, and recheck whether spark is generated between the spark plug and
the grounded metal portion.
Is the inspection result normal?
YES >> GO TO 8.
(+) (–)
Voltag e
Connector Terminal Connector Terminal
F1025
E16 108 Battery voltage 29
30
31
Spark should be generated.
JMBIA0066GB
Spark should be generated.
EC-896
< COMPONENT DIAGNOSIS >[MR18DE]
P1143 HO2S1
P1143 HO2S1
DescriptionINFOID:0000000001161872
The heated oxygen sensor 1 is placed into the exhaust manifold. It
detects the amount of oxygen in the exhaust gas compared to the
outside air. The heated oxygen sensor 1 has a closed-end tube
made of ceramic zirconia. The zirconia generates voltage from
approximately 1V in richer conditions to 0V in leaner conditions. The
heated oxygen sensor 1 signal is sent to the ECM. The ECM adjusts
the injection pulse duration to achieve the ideal air-fuel ratio. The
ideal air-fuel ratio occurs near the radical change from 1V to 0V.
DTC LogicINFOID:0000000001161873
DTC DETECTION LOGIC
To judge the malfunction, the output from the heated oxygen sensor
1 is monitored to determine whether the “rich” output is sufficiently
high and whether the “lean” output is sufficiently low. When both the
outputs are shifting to the lean side, the malfunction will be detected.
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Always perform at a temperature above -10°C (14°F)
SEF463R
SEF288D
SEF300U
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1143Heated oxygen sensor 1
lean shift monitoringThe maximum and minimum voltage from the
sensor are not reached to the specified voltages. Heated oxygen sensor 1
Heated oxygen sensor 1 heater
Fuel pressure
Fuel injector
Intake air leaks
P1144 HO2S1
EC-901
< COMPONENT DIAGNOSIS >[MR18DE]
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
P1144 HO2S1
DescriptionINFOID:0000000001161876
The heated oxygen sensor 1 is placed into the exhaust manifold. It
detects the amount of oxygen in the exhaust gas compared to the
outside air. The heated oxygen sensor 1 has a closed-end tube
made of ceramic zirconia. The zirconia generates voltage from
approximately 1V in richer conditions to 0V in leaner conditions. The
heated oxygen sensor 1 signal is sent to the ECM. The ECM adjusts
the injection pulse duration to achieve the ideal air-fuel ratio. The
ideal air-fuel ratio occurs near the radical change from 1V to 0V.
DTC LogicINFOID:0000000001161877
DTC DETECTION LOGIC
To judge the malfunction, the output from the heated oxygen sensor
1 is monitored to determine whether the “rich” output is sufficiently
high and “lean” output is sufficiently low. When both the outputs are
shifting to the rich side, the malfunction will be detected.
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Always perform at a temperature above -10°C (14°F).
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
SEF463R
SEF288D
SEF299U
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1144Heated oxygen sensor 1
rich shift monitoringThe maximum and minimum voltages from the
sensor are beyond the specified voltages. Heated oxygen sensor 1
Heated oxygen sensor 1 heater
Fuel pressure
Fuel injector
EC-906
< COMPONENT DIAGNOSIS >[MR18DE]
P1146 HO2S2
P1146 HO2S2
DescriptionINFOID:0000000001161880
The heated oxygen sensor 2, after three way catalyst (manifold),
monitors the oxygen level in the exhaust gas on each bank.
Even if switching characteristics of the heated oxygen sensor 1 are
shifted, the air-fuel ratio is controlled to stoichiometric, by the signal
from the heated oxygen sensor 2.
This sensor is made of ceramic zirconia. The zirconia generates volt-
age from approximately 1V in richer conditions to 0V in leaner condi-
tions.
Under normal conditions the heated oxygen sensor 2 is not used for
engine control operation.
DTC LogicINFOID:0000000001161881
DTC DETECTION LOGIC
The heated oxygen sensor 2 has a much longer switching time
between rich and lean than the heated oxygen sensor 1. The oxygen
storage capacity of the three way catalyst (manifold) causes the
longer switching time. To judge the malfunctions of heated oxygen
sensor 2, ECM monitors whether the minimum voltage of the sensor
is sufficiently low during the various driving condition such as fuel-
cut.
DTC CONFIRMATION PROCEDURE
1.INSPECTION START
Do you have CONSULT-III?
Do you have CONSULT-III?
YES >> GO TO 2.
NO >> GO TO 11.
2.PRECONDITIONING
“COMPLETED” will appear on CONSULT-III screen when all tests “COND1”, “COND2” and “COND3” are
completed.
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
For the best results, perform ″DTC WORK SUPPORT″ at a temperature of 0 to 30°C (32 to 86°F).
Never stop engine during this procedure. If the engine is stopped, retry this procedure from step 2 in
Procedure for COND1.
CAUTION:
Always drive at safe speed.
SEF327R
PBIB0554E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1146Heated oxygen sensor 2
minimum voltage moni-
toringThe minimum voltage from the sensor is not
reached to the specified voltage. Harness or connectors
(The sensor circuit is open or shorted)
Heated oxygen sensor 2
Fuel pressure
Fuel injector
Intake air leaks
EC-912
< COMPONENT DIAGNOSIS >[MR18DE]
P1147 HO2S2
P1147 HO2S2
DescriptionINFOID:0000000001161885
The heated oxygen sensor 2, after three way catalyst (manifold),
monitors the oxygen level in the exhaust gas on each bank.
Even if switching characteristics of the heated oxygen sensor 1 are
shifted, the air-fuel ratio is controlled to stoichiometric, by the signal
from the heated oxygen sensor 2.
This sensor is made of ceramic zirconia. The zirconia generates volt-
age from approximately 1V in richer conditions to 0V in leaner condi-
tions.
Under normal conditions the heated oxygen sensor 2 is not used for
engine control operation.
DTC LogicINFOID:0000000001161886
DTC DETECTION LOGIC
The heated oxygen sensor 2 has a much longer switching time
between rich and lean than the heated oxygen sensor 1. The oxygen
storage capacity of the three way catalyst (manifold) causes the
longer switching time. To judge the malfunctions of heated oxygen
sensor 2, ECM monitors whether the maximum voltage of the sensor
is sufficiently high during the various driving condition such as fuel-
cut.
DTC CONFIRMATION PROCEDURE
1.INSPECTION START
Do you have CONSULT-III?
Do you have CONSULT-III?
YES >> GO TO 2.
NO >> GO TO 11.
2.PRECONDITIONING
“COMPLETED” will appear on CONSULT-III screen when all tests “COND1”, “COND2” and “COND3” are
completed.
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
For the best results, perform ″DTC WORK SUPPORT″ at a temperature of 0 to 30°C (32 to 86°F).
Never stop engine during this procedure. If the engine is stopped, retry this procedure from step 2 in
Procedure for COND1.
CAUTION:
Always drive at safe speed.
SEF327R
SEF259VA
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1146Heated oxygen sensor 2
circuit low voltageThe maximum voltage from the sensor is not
reached to the specified voltage. Harness or connectors
(The sensor circuit is open or shorted)
Heated oxygen sensor 2
Fuel pressure
Fuel injector
Intake air leaks