Component DescriptionNCEC0144The heated oxygen sensor 2 (rear) (Rear HO2S), after three way
catalyst, monitors the oxygen level in the exhaust gas.
Even if switching characteristics of the heated oxygen sensor 1
(front) are shifted, the air fuel ratio is controlled to stoichiometric,
by the signal from the heated oxygen sensor 2 (rear).
This sensor is made of ceramic zirconia. The zirconia generates
voltage from approximately 1V in richer conditions to 0V in leaner
conditions.
Under normal conditions the heated oxygen sensor 2 (rear) is not
used for engine control operation.
CONSULT-II Reference Value in Data Monitor
Mode
NCEC0145Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 (B)
IEngine: After warming upRevving engine from idle to 3,000
rpm0 - 0.3V+,Approx. 0.6 - 1.0V
HO2S2 MNTR
(B1)LEAN+,RICH
ECM Terminals and Reference ValueNCEC0146Specification data are reference values and are measured between each terminal and 48 (ECM ground).
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
63 LHeated oxygen sensor 2
(rear)[Engine is running]
IAfter warming up to normal operating temperature
and engine speed is 3,000 rpm0 - Approximately 1.0V
On Board Diagnosis LogicNCEC0147The heated oxygen sensor 2 (rear) has a much longer switching
time between rich and lean than the heated oxygen sensor 1
(front). The oxygen storage capacity before the three way catalyst
causes the longer switching time. To judge the malfunctions of
heated oxygen sensor 2 (rear), ECM monitors whether the mini-
mum voltage of the sensor is sufficiently low during various driving
conditions such as fuel-cut.
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0137
0137IThe minimum voltage from the sensor does not reach
the specified voltage.IHarness or connectors
(The sensor circuit is open or shorted.)
IHeated oxygen sensor 2 (rear)
IFuel pressure
IInjectors
SEF327R
SEF258V OK NG
1V
0.43V
0V
DTC P0137 HEATED OXYGEN SENSOR 2
(REAR) (MIN. VOLTAGE MONITORING)SR20DE
Component Description
EC-180
Diagnostic ProcedureNCEC0151
1 RETIGHTEN GROUND SCREWS
1. Turn ignition switch ªOFFº.
2. Loosen and retighten engine ground screws.
SEF202X
©GO TO 2.
2 CLEAR THE SELF-LEARNING DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select ªSELF-LEARN CONTROLº in ªWORK SUPPORTº mode with CONSULT-II.
3. Clear the self-learning control coefficient by touching ªCLEARº.
SEF652Y4. Run engine for at least 10 minutes at idle speed.Is the 1st trip DTC P0172 detected? Is it difficult to start engine?
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch ªOFFº.
3. Disconnect mass air flow sensor harness connector, and restart and run engine for at least 3 seconds at idle speed.
SEF203X4. Stop engine and reconnect mass air flow sensor harness connector.
5. Make sure diagnostic trouble code No. 0100 is displayed in Diagnostic Test Mode II.
6. Erase the diagnostic test mode II (Self-diagnostic results) memory. Refer to ªHOW TO ERASE EMISSION-RELATED DIAGNOSTIC
INFORMATIONº, EC-SR-56.
7. Make sure diagnostic trouble code No. 0000 is displayed in Diagnostic Test Mode II.
8. Run engine for at least 10 minutes at idle speed.Is the 1st trip DTC 0172 detected? Is it difficult to start engine?
YesorNo
Ye s©Perform trouble diagnosis for DTC P0172. Refer to EC-SR-218.
No©GO TO 3.
Intake manifold
collector
Engine
ground
Mass air flow sensor
harness connector
Air cleaner
DTC P0137 HEATED OXYGEN SENSOR 2
(REAR) (MIN. VOLTAGE MONITORING)SR20DE
Diagnostic Procedure
EC-184
Component DescriptionNCEC0153The heated oxygen sensor 2 (rear) (Rear HO2S), after three way
catalyst, monitors the oxygen level in the exhaust gas.
Even if switching characteristics of the heated oxygen sensor 1
(front) are shifted, the air fuel ratio is controlled to stoichiometric,
by the signal from the heated oxygen sensor 2 (rear).
This sensor is made of ceramic zirconia. The zirconia generates
voltage from approximately 1V in richer conditions to 0V in leaner
conditions.
Under normal conditions the heated oxygen sensor 2 (rear) is not
used for engine control operation.
CONSULT-II Reference Value in Data Monitor
Mode
NCEC0154Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 (B1)
IEngine: After warming upRevving engine from idle to 3,000
rpm0 - 0.3V+,Approx. 0.6 - 1.0V
HO2S2 MNTR
(B1)LEAN+,RICH
ECM Terminals and Reference ValueNCEC0155Specification data are reference values and are measured between each terminal and 48 (ECM ground).
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
63 LHeated oxygen sensor 2
(rear)[Engine is running]
IAfter warming up to normal operating temperature
and engine speed is 2,000 rpm0 - Approximately 1.0V
On Board Diagnosis LogicNCEC0156The heated oxygen sensor 2 (rear) has a much longer switching
time between rich and lean than the heated oxygen sensor 1
(front). The oxygen storage capacity before the three way catalyst
causes the longer switching time. To judge the malfunctions of
heated oxygen sensor 2 (rear), ECM monitors whether the maxi-
mum voltage of the sensor is sufficiently high during various driv-
ing conditions such as fuel-cut.
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0138
0138IThe maximum voltage from the sensor does not reach
the specified voltage.IHarness or connectors
(The sensor circuit is open or shorted.)
IHeated oxygen sensor 2 (rear)
IFuel pressure
IInjectors
IIntake air leaks
SEF327R
SEF259V OK NG
1V
0.43V
0V
DTC P0138 HEATED OXYGEN SENSOR 2
(REAR) (MAX. VOLTAGE MONITORING)SR20DE
Component Description
EC-187
Diagnostic ProcedureNCEC0160
1 RETIGHTEN GROUND SCREWS
1. Turn ignition switch ªOFFº.
2. Loosen and retighten engine ground screws.
SEF202X
©GO TO 2.
2 CLEAR THE SELF-LEARNING DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select ªSELF-LEARN CONTROLº in ªWORK SUPPORTº mode with CONSULT-II.
3. Clear the self-learning control coefficient by touching ªCLEARº.
SEF652Y4. Run engine for at least 10 minutes at idle speed.Is the 1st trip DTC P0171 detected? Is it difficult to start engine?
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch ªOFFº.
3. Disconnect mass air flow sensor harness connector, and restart and run engine for at least 3 seconds at idle speed.
SEF203X4. Stop engine and reconnect mass air flow sensor harness connector.
5. Make sure diagnostic trouble code No. 0100 is displayed in Diagnostic Test Mode II.
6. Erase the diagnostic test mode II (Self-diagnostic results) memory. Refer to ªHOW TO ERASE EMISSION-RELATED DIAGNOSTIC
INFORMATIONº, EC-SR-56.
7. Make sure diagnostic trouble code No. 0000 is displayed in Diagnostic Test Mode II.
8. Run engine for at least 10 minutes at idle speed.Is the 1st trip DTC 0171 detected? Is it difficult to start engine?
YesorNo
Ye s©Perform trouble diagnosis for DTC P0171. Refer to EC-SR-212.
No©GO TO 3.
Intake manifold
collector
Engine
ground
Air cleaner Mass air flow sensor
harness connector
DTC P0138 HEATED OXYGEN SENSOR 2
(REAR) (MAX. VOLTAGE MONITORING)SR20DE
Diagnostic Procedure
EC-191
Component DescriptionNCEC0162The heated oxygen sensor 2 (rear) (Rear HO2S), after three way
catalyst, monitors the oxygen level in the exhaust gas.
Even if switching characteristics of the heated oxygen sensor 1
(front) are shifted, the air fuel ratio is controlled to stoichiometric,
by the signal from the heated oxygen sensor 2 (rear).
This sensor is made of ceramic zirconia. The zirconia generates
voltage from approximately 1V in richer conditions to 0V in leaner
conditions.
Under normal conditions the heated oxygen sensor 2 (rear) is not
used for engine control operation.
CONSULT-II Reference Value in Data Monitor
Mode
NCEC0163Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 (B1)
IEngine: After warming upRevving engine from idle to 3,000
rpm0 - 0.3V+,Approx. 0.6 - 1.0V
HO2S2 MNTR
(B1)LEAN+,RICH
ECM Terminals and Reference ValueNCEC0164Specification data are reference values and are measured between each terminal and 48 (ECM ground).
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
63 LHeated oxygen sensor 2
(rear)[Engine is running]
IAfter warming up to normal operating temperature
and revving engine from idle to 2,000 rpm0 - Approximately 1.0V
On Board Diagnosis LogicNCEC0165The heated oxygen sensor 2 (rear) has a much longer switching
time between rich and lean than the heated oxygen sensor 1
(front). The oxygen storage capacity before the three way catalyst
causes the longer switching time. To judge the malfunctions of
heated oxygen sensor 2 (rear), ECM monitors whether the switch-
ing response of the sensor's voltage is faster than specified during
various driving conditions such as fuel-cut.
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0139
0139IIt takes more than the specified time for the sensor to
respond between rich and lean.IHarness or connectors
(The sensor circuit is open or shorted.)
IHeated oxygen sensor 2 (rear)
IFuel pressure
IInjectors
IIntake air leaks
SEF327R
SEF302U OK NG
DTC P0139 HEATED OXYGEN SENSOR 2
(REAR) (RESPONSE MONITORING)SR20DE
Component Description
EC-194
Diagnostic ProcedureNCEC0169
1 RETIGHTEN GROUND SCREWS
1. Turn ignition switch ªOFFº.
2. Loosen and retighten engine ground screws.
SEF202X
©GO TO 2.
2 CLEAR THE SELF-LEARNING DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select ªSELF-LEARN CONTROLº in ªWORK SUPPORTº mode with CONSULT-II.
3. Clear the self-learning control coefficient by touching ªCLEARº.
SEF652Y4. Run engine for at least 10 minutes at idle speed.Is the 1st trip DTC P0172 detected? Is it difficult to start engine?
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch ªOFFº.
3. Disconnect mass air flow sensor harness connector, and restart and run engine for at least 3 seconds at idle speed.
SEF203X4. Stop engine and reconnect mass air flow sensor harness connector.
5. Make sure diagnostic trouble code No. 0100 is displayed in Diagnostic Test Mode II.
6. Erase the diagnostic test mode II (Self-diagnostic results) memory. Refer to ªHOW TO ERASE EMISSION-RELATED DIAGNOSTIC
INFORMATIONº, EC-SR-56.
7. Make sure diagnostic trouble code No. 0000 is displayed in Diagnostic Test Mode II.
8. Run engine for at least 10 minutes at idle speed.Is the 1st trip DTC 0172 detected? Is it difficult to start engine?
YesorNo
Ye s©Perform trouble diagnosis for DTC P0172. Refer to EC-SR-218.
No©GO TO 3.
Intake manifold
collector
Engine
ground
Mass air flow sensor
harness connector
Air cleaner
DTC P0139 HEATED OXYGEN SENSOR 2
(REAR) (RESPONSE MONITORING)SR20DE
Diagnostic Procedure
EC-198
Component DescriptionNCEC0171The heated oxygen sensor 2 (rear) (Rear HO2S), after three way
catalyst, monitors the oxygen level in the exhaust gas.
Even if switching characteristics of the heated oxygen sensor 1
(front) are shifted, the air fuel ratio is controlled to stoichiometric,
by the signal from the heated oxygen sensor 2 (rear).
This sensor is made of ceramic zirconia. The zirconia generates
voltage from approximately 1V in richer conditions to 0V in leaner
conditions.
Under normal conditions the heated oxygen sensor 2 (rear) is not
used for engine control operation.
CONSULT-II Reference Value in Data Monitor
Mode
NCEC0172Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 (B1)
IEngine: After warming upRevving engine from idle to 3,000
rpm0 - 0.3V+,Approx. 0.6 - 1.0V
HO2S2 MNTR
(B1)LEAN+,RICH
ECM Terminals and Reference ValueNCEC0173Specification data are reference values and are measured between each terminal and 48 (ECM ground).
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
63 LHeated oxygen sensor 2
(rear)[Engine is running]
IAfter warming up to normal operating temperature
and revving engine from idle to 2,000 rpm0 - Approximately 1.0V
On Board Diagnosis LogicNCEC0174The heated oxygen sensor 2 (rear) has a much longer switching
time between rich and lean than the heated oxygen sensor 1
(front). The oxygen storage capacity before the three way catalyst
causes the longer switching time. To judge the malfunctions of
heated oxygen sensor 2 (rear), ECM monitors whether or not the
voltage is too high during various driving conditions such as fuel-
cut.
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0140
0140IAn excessively high voltage from the sensor is sent to
ECM.IHarness or connectors
(The sensor circuit is open or shorted.)
IHeated oxygen sensor 2 (rear)
SEF327R
SEF305U OK NG
DTC P0140 HEATED OXYGEN SENSOR 2
(REAR) (HIGH VOLTAGE)SR20DE
Component Description
EC-201
DescriptionNCEC0180SYSTEM DESCRIPTIONNCEC0180S01
Sensor Input Signal to ECMECM func-
tionActuator
Camshaft position sensor Engine speedHeated oxy-
gen sensor
2 (rear)
heater con-
trolHeated oxygen sensor 2 (rear)
heater
The ECM performs ON/OFF control of the heated oxygen sensor 2 (rear) heater corresponding to the engine
speed.
OPERATIONNCEC0180S02
Engine condition Heated oxygen sensor 2 (rear) heater
Engine stopped OFF
Engine is running below 3,600 rpm. [After driving for 2 minutes at a speed of 70 km/h
(43 MPH) or more]ON
CONSULT-II Reference Value in Data Monitor
Mode
NCEC0181Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 HTR (B1)IEngine speed: Below 3,600 rpm [After driving for 2 minutes at a
speed of 70 km/h (43 MPH) or more]ON
IIgnition switch ON (Engine stopped) OFF
ECM Terminals and Reference ValueNCEC0182Specification data are reference values and are measured between each terminal and 48 (ECM ground).
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
3 W/RHeated oxygen sensor 2
(rear) heater[Engine is running]
IBelow 3,600 rpm [After driving for 2 minutes at a
speed of 70 km/h (43 MPH) or more]Approximately 0.7V
[Ignition switch ªONº]
IEngine stoppedBATTERY VOLTAGE
(11 - 14V)
On Board Diagnosis LogicNCEC0183
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0141
0141IThe current amperage in the heated oxygen sensor 2
(rear) heater circuit is out of the normal range.
(An improper voltage drop signal is sent to ECM through
the heated oxygen sensor 2 (rear) heater.)IHarness or connectors
(The heated oxygen sensor 2 (rear) heater cir-
cuit is open or shorted.)
IHeated oxygen sensor 2 (rear) heater
DTC P0141 HEATED OXYGEN SENSOR 2 (REAR) HEATERSR20DE
Description
EC-207