EC-784
< COMPONENT DIAGNOSIS >[MR18DE]
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
NOTE:
Check “A/F ALPHA-B1” for approximately 1 minute because they may fluctuate. It is NG if the indication is
out of the SP value even a little.
Is the measurement value within the SP value?
YES >> GO TO 17.
NO-1 >> Less than the SP value: GO TO 2.
NO-2 >> More than the SP value: GO TO 3.
2.CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within the
SP value.
Is the measurement value within the SP value?
YES >> GO TO 4.
NO >> More than the SP value: GO TO 19.
3.CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within the
SP value.
Is the measurement value within the SP value?
YES >> GO TO 6.
NO-1 >> More than the SP value: GO TO 6.
NO-2 >> Less than the SP value: GO TO 25.
4.CHECK “A/F ALPHA-B1”
1. Stop the engine.
2. Disconnect PCV hose, and then plug it.
3. Start engine.
4. Select “A/F ALPHA-B1” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within
the SP value.
Is the measurement value within the SP value?
YES >> GO TO 5.
NO >> GO TO 6.
5.CHANGE ENGINE OIL
1. Stop the engine.
2. Change engine oil.
NOTE:
This symptom may occur when a large amount of gasoline is mixed with engine oil because of driving
conditions (such as when engine oil temperature does not rise enough since a journey distance is too
short during winter). The symptom will not be detected after changing engine oil or changing driving con-
dition.
>>INSPECTION END
6.CHECK FUEL PRESSURE
Check fuel pressure. (Refer to EC-1035, "
Inspection".)
Is the inspection result normal?
YES >> GO TO 9.
NO-1 >> Fuel pressure is too high: Replace “fuel filter and fuel pump assembly” and then GO TO 8.
NO-2 >> Fuel pressure is too low: GO TO 7.
7.DETECT MALFUNCTIONING PART
Check fuel hoses and fuel tubes for clogging
Is the inspection result normal?
YES >> Replace “fuel filter and fuel pump assembly” and then GO TO 8.
NO >> Repair or replace and then GO TO 8.
8.CHECK “A/F ALPHA-B1”
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
EC-785
< COMPONENT DIAGNOSIS >[MR18DE]
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1. Start engine.
2. Select “A/F ALPHA-B1” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within
the SP value.
Is the measurement value within the SP value?
YES >> INSPECTION END
NO >> GO TO 9.
9.PERFORM POWER BALANCE TEST
1. Perform “POWER BALANCE” in “ACTIVE TEST” mode.
2. Make sure that the each cylinder produces a momentary engine speed drop.
Is the inspection result normal?
YES >> GO TO 12.
NO >> GO TO 10.
10.DETECT MALFUNCTIONING PART
Check the following.
1. Ignition coil and its circuit (Refer to EC-981, "
Component Function Check".)
2. Fuel injector and its circuit (Refer to EC-975, "
Component Function Check".)
3. Intake air leakage
4. Low compression pressure (Refer to EM-151, "
Checking Compression Pressure".)
Is the inspection result normal?
YES >> Replace fuel injector and then GO TO 11.
NO >> Repair or replace malfunctioning part and then GO TO 11.
11 .CHECK “A/F ALPHA-B1”
1. Start engine.
2. Select “A/F ALPHA-B1” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within
the SP value.
Is the measurement value within the SP value?
YES >> INSPECTION END
NO >> GO TO 12.
12.CHECK HEATED OXYGEN SENSOR 1 FUNCTION
1. Run engine at about 2,000 rpm for about 2minutes under no load.
2. Select “HO2S MNTR (B1)”, in “DATA MONITOR” mode.
3. Running engine at 2,000 rpm under no load (The engine is warmed up to normal operating temperature.),
check that the monitor fluctuates between LEAN and RICH more than 5 times during 10 seconds.
Is the inspection result more than 5 times during 10 seconds?
YES >> GO TO 15.
NO >> GO TO 13.
13.CHECK HEATED OXYGEN SENSOR 1 CIRCUIT
Check heated oxygen sensor 1 and its circuit, refer to.
>> GO TO 14.
14.CHECK “A/F ALPHA-B1”
1. Start engine.
2. Select “A/F ALPHA-B1” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within
the SP value.
Is the measurement value within the SP value?
YES >> INSPECTION END
NO >> GO TO 15.1 time : RICH → LEAN → RICH
2 times : RICH → LEAN → RICH → LEAN → RICH
P0133 HO2S1
EC-817
< COMPONENT DIAGNOSIS >[MR18DE]
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P0133 HO2S1
DescriptionINFOID:0000000001161789
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:0000000001161790
DTC DETECTION LOGIC
To judge the malfunction of heated oxygen sensor 1, this diagnosis
measures response time of heated oxygen sensor 1 signal. The time
is compensated by engine operating (speed and load), fuel feedback
control constant, and heated oxygen sensor 1 temperature index.
Judgment is based on whether the compensated time (heated oxy-
gen sensor 1 cycling time index) is inordinately long or not.
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
SEF463R
SEF288D
PBIB2991E
DTC No. Trouble diagnosis name DTC detecting condition Possible Cause
P0133Heated oxygen sensor 1
circuit slow response The response of the voltage signal from the
sensor takes more than the specified time. Harness or connectors
(The sensor circuit is open or short-
ed.)
Heated oxygen sensor 1
Fuel pressure
Fuel injector
Intake air leaks
Exhaust gas leaks
PCV valve
Mass air flow sensor
P0139 HO2S2
EC-835
< COMPONENT DIAGNOSIS >[MR18DE]
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P0139 HO2S2
DescriptionINFOID:0000000001161805
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:0000000001161806
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 switching response of the sen-
sor's voltage is faster than specified during the various driving condi-
tion 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 PERFORM PRO-
CEDURE FOR COND1 - II.
SEF327R
SEF302U
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0139Heated oxygen sensor 2
circuit slow responseIt takes more time for the sensor to respond be-
tween rich and lean than the specified time. Harness or connectors
(The sensor circuit is open or shorted)
Heated oxygen sensor 2
Fuel pressure
Fuel injector
Intake air leaks
EC-844
< COMPONENT DIAGNOSIS >[MR18DE]
P0171 FUEL INJECTION SYSTEM FUNCTION
P0171 FUEL INJECTION SYSTEM FUNCTION
DTC LogicINFOID:0000000001161814
DTC DETECTION LOGIC
With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensors 1. The
ECM calculates the necessary compensation to correct the offset between the actual and the theoretical
ratios.
In case the amount of the compensation value is extremely large (The actual mixture ratio is too lean.), the
ECM judges the condition as the fuel injection system malfunction and lights up the MI (2 trip detection logic).
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. Clear the mixture ratio self-learning value. Refer to EC-696, "
MIXTURE RATIO SELF-LEARNING VALUE
CLEAR : Special Repair Requirement".
2. Start engine.
Is it difficult to start engine?
YES >> GO TO 3.
NO >> GO TO 4.
3.RESTART ENGINE
If it is difficult to start engine, the fuel injection system has a malfunction, too.
Crank engine while depressing accelerator pedal.
Does engine start?
YES >> Go to EC-845, "Diagnosis Procedure".
NO >> Check exhaust and intake air leak visually.
4.PERFORM DTC CONFIRMATION PROCEDURE-II
1. Start engine and let it idle for at least 10 minutes.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-845, "Diagnosis Procedure".
NO >> GO TO 5.
5.PERFORM DTC CONFIRMATION PROCEDURE-III
1. Turn ignition switch OFF and wait at least 10 seconds.
Sensor Input signal to ECM ECM function Actuator
Heated oxygen sensor 1Density of oxygen in exhaust gas
(Mixture ratio feedback signal)Fuel injection control Fuel injector
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0171Fuel injection system too
lean Fuel injection system does not operate properly.
The amount of mixture ratio compensation is too
large. (The mixture ratio is too lean.) Intake air leaks
Heated oxygen sensor 1
Fuel injector
Exhaust gas leaks
Incorrect fuel pressure
Lack of fuel
Mass air flow sensor
Incorrect PCV hose connection
EC-846
< COMPONENT DIAGNOSIS >[MR18DE]
P0171 FUEL INJECTION SYSTEM FUNCTION
6. Also check harness for short to power.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK FUEL PRESSURE
Check fuel pressure. Refer to EC-1035, "
Inspection".
Is the inspection result normal?
YES >> GO TO 6.
NO >> GO TO 5.
5. 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
6.CHECK MASS AIR FLOW SENSOR
With CONSULT-III
1. Install all removed parts.
2. Check “MASS AIR FLOW” in “DATA MONITOR” mode with CONSULT-III.
For specification, refer to EC-1038, "
Mass Air Flow Sensor".
With GST
1. Install all removed parts.
2. Check mass air flow sensor signal in Service $01 with GST.
For specification, refer to EC-1038, "
Mass Air Flow Sensor".
Is the measurement value within the specification?
YES >> GO TO 7.
NO >> Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or
grounds. Refer to EC-799, "
DTC Logic".
7.CHECK FUNCTION OF FUEL INJECTOR
With CONSULT-III
1. Start engine.
2. Perform “POWER BALANCE” in “ACTIVE TEST” mode with CONSULT-III.
3. Make sure that each circuit produces a momentary engine speed drop.
Without CONSULT-III
1. Let engine idle.
2. Listen to each fuel injector operating sound.
Is the inspection result normal?
YES >> GO TO 8.
NO >> Perform trouble diagnosis for FUEL INJECTOR, refer to
EC-975, "
Component Function Check".
8.CHECK FUEL INJECTOR
HO2S1 ECM
Ground Continuity
Connector Terminal Connector Terminal
F12 4 F11 49 Ground Not existed
Clicking noise should be heard.
PBIB3332E
EC-848
< COMPONENT DIAGNOSIS >[MR18DE]
P0172 FUEL INJECTION SYSTEM FUNCTION
P0172 FUEL INJECTION SYSTEM FUNCTION
DTC LogicINFOID:0000000001161816
DTC DETECTION LOGIC
With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensors 1. The
ECM calculates the necessary compensation to correct the offset between the actual and the theoretical
ratios.
In case the amount of the compensation value is extremely large (The actual mixture ratio is too rich.), the
ECM judges the condition as the fuel injection system malfunction and lights up the MI (2 trip detection logic).
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. Clear the mixture ratio self-learning value. Refer to EC-696, "
MIXTURE RATIO SELF-LEARNING VALUE
CLEAR : Special Repair Requirement".
2. Start engine.
Is it difficult to start engine?
YES >> GO TO 3.
NO >> GO TO 4.
3.RESTART ENGINE
If it is difficult to start engine, the fuel injection system has a malfunction, too.
Crank engine while depressing accelerator pedal.
Does engine start?
YES >> Go to EC-849, "Diagnosis Procedure".
NO >> Remove spark plugs and check for fouling, etc.
4.PERFORM DTC CONFIRMATION PROCEDURE-II
1. Start engine and let it idle for at least 10 minutes.
Is 1st trip DTC detected?
YES >> Go to EC-849, "Diagnosis Procedure".
NO >> GO TO 5.
5.PERFORM DTC CONFIRMATION PROCEDURE-III
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Start engine and drive the vehicle under the similar conditions to (1st trip) Freeze Frame Data for 10 min-
utes. Refer to the table below.
Hold the accelerator pedal as steady as possible.
Sensor Input signal to ECM ECM function Actuator
Heated oxygen sensor 1Density of oxygen in exhaust gas
(Mixture ratio feedback signal)Fuel injection control Fuel injector
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0172Fuel injection system too
rich Fuel injection system does not operate properly.
The amount of mixture ratio compensation is too
large. (The mixture ratio is too rich.) Heated oxygen sensor 1
Fuel injector
Exhaust gas leaks
Incorrect fuel pressure
Mass air flow sensor
EC-850
< COMPONENT DIAGNOSIS >[MR18DE]
P0172 FUEL INJECTION SYSTEM FUNCTION
6. Also check harness for short to power.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK FUEL PRESSURE
Check fuel pressure. Refer to EC-1035, "
Inspection".
Is the inspection result normal?
YES >> GO TO 6.
NO >> GO TO 5.
5. 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
6.CHECK MASS AIR FLOW SENSOR
With CONSULT-III
1. Install all removed parts.
2. Check “MASS AIR FLOW” in “DATA MONITOR” mode with CONSULT-III.
For specification, refer to EC-1038, "
Mass Air Flow Sensor".
With GST
1. Install all removed parts.
2. Check mass air flow sensor signal in “Service $01” with GST.
For specification, refer to EC-1038, "
Mass Air Flow Sensor".
Is the measurement value within the specification?
YES >> GO TO 7.
NO >> Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or
grounds. Refer to EC-799, "
DTC Logic".
7.CHECK FUNCTION OF FUEL INJECTOR
With CONSULT-III
1. Start engine.
2. Perform “POWER BALANCE” in “ACTIVE TEST” mode with CONSULT-III.
3. Make sure that each circuit produces a momentary engine speed drop.
Without CONSULT-III
1. Let engine idle.
2. Listen to each fuel injector operating sound.
Is the inspection result normal?
YES >> GO TO 8.
NO >> Perform trouble diagnosis for FUEL INJECTOR, refer to
EC-975, "
Component Function Check".
8.CHECK FUELINJECTOR
1. Remove fuel injector assembly. Refer to EM-162, "
Removal and Installation".
Keep fuel hose and all fuel injectors connected to fuel tube.
2. Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
3. Disconnect all fuel injector harness connectors.
4. Disconnect all ignition coil harness connectors.
5. Prepare pans or saucers under each fuel injectors.
Clicking noise should be heard.
PBIB3332E