
5 CLEAR THE SELF-LEARNING DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select ªSELF-LEARNING CONTº in ªWORK SUPPORTº mode with CONSULT-II.
3. Clear the self-learning control coefficient by touching ªSTARTº.
SEF652Y
4. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171 or 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.
JEF105Y
4. 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-QG-44.
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 or 0172 detected? Is it difficult to start engine?
YesorNo
Ye s©Perform trouble diagnosis for DTC P0171, P0172. Refer to EC-QG-208, 215.
No©GO TO 6.
6 CHECK INPUT SIGNAL CIRCUIT
1. Disconnect heated oxygen sensor 1 (front) harness connector and ECM harness connector.
2. Check harness continuity between ECM terminal 62 and heated oxygen sensor 1 (front) harness connector terminal 2.
Refer to wiring diagram.
Continuity should exist.
3. Check harness continuity between ECM terminal 62 (or terminal 2) and ground.
Continuity should not exist.
4. Also check harness for short to power.
OK or NG
OK©GO TO 7.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
DTC P0133 HEATED OXYGEN SENSOR 1 (FRONT)
(RESPONSE MONITORING)QG16I18DE
Diagnostic Procedure (Cont'd)
EC-156

7 CHECK HEATED OXYGEN SENSOR 1 HEATER (FRONT)
Refer to ªComponent Inspectionº, EC-QG-170.
OK or NG
OK©GO TO 8.
NG©Replace heated oxygen sensor 1 (front).
8 CHECK HEATED OXYGEN SENSOR 1 (FRONT)
Refer to ªComponent Inspectionº, EC-QG-158.
OK or NG
OK©GO TO 9.
NG©Replace heated oxygen sensor 1 (front).
9 CHECK MASS AIR FLOW SENSOR
Refer to ªComponent Inspectionº, EC-QG-115.
OK or NG
OK©GO TO 10.
NG©Replace mass air flow sensor.
10 CHECK PCV VALVE
Refer to ªPositive Crankcase Ventilationº, EC-QG-28.
OK or NG
OK©GO TO 11.
NG©Repair or replace PCV valve.
11 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-QG-102.
©INSPECTION END
DTC P0133 HEATED OXYGEN SENSOR 1 (FRONT)
(RESPONSE MONITORING)QG16I18DE
Diagnostic Procedure (Cont'd)
EC-157

Component InspectionNLEC0127HEATED OXYGEN SENSOR 1 (FRONT)NLEC0127S02With CONSULT-II
1) Start engine and warm it up to normal operating temperature.
2) Select ªMANU TRIGº in ªDATA MONITORº mode, and select
ªHO2S1 (B1)º and ªHO2S1 MNTR (B1)º.
3) Hold engine speed at 2,000 rpm under no load during the fol-
lowing steps.
4) Touch ªRECORDº on CONSULT-II screen.
5) Check the following.
IªHO2S1 MNTR (B1)º in ªDATA MONITORº mode changes from
ªRICHº to ªLEANº to ªRICHº five times in 10 seconds.
5 times (cycles) are counted as shown below:
R = ªHO2S1 MNTR (B1)º, ªRICHº
L = ªHO2S1 MNTR (B1)º, ªLEANº
IªHO2S1 (B1)º voltage goes above 0.6V at least once.
IªHO2S1 (B1)º voltage goes below 0.3V at least once.
IªHO2S1 (B1)º voltage never exceeds 1.0V.
CAUTION:
IDiscard any heated oxygen sensor which has been
dropped from a height of more than 0.5 m (19.7 in) onto a
hard surface such as a concrete floor; use a new one.
IBefore installing new oxygen sensor, clean exhaust sys-
tem threads using Oxygen Sensor Thread Cleaner tool
and approved anti-seize lubricant.
Without CONSULT-II
1) Start engine and warm it up to normal operating temperature.
2) Set voltmeter probes between ECM terminal 62 (HO2S1 sig-
nal) and engine ground.
3) Check the following with engine speed held at 2,000 rpm con-
stant under no load.
IMalfunction indicator lamp goes on more than five times within
10 seconds in Diagnostic Test Mode II [HEATED OXYGEN
SENSOR 1 MONITOR (FRONT).]
IThe maximum voltage is over 0.6V at least one time.
IThe minimum voltage is below 0.3V at least one time.
SEF646Y
SEF647Y
SEF648Y
SEF011X
DTC P0133 HEATED OXYGEN SENSOR 1 (FRONT)
(RESPONSE MONITORING)QG16I18DE
Component Inspection
EC-158

IThe voltage never exceeds 1.0V.
CAUTION:
IDiscard any heated oxygen sensor which has been
dropped from a height of more than 0.5 m (19.7 in) onto a
hard surface such as a concrete floor; use a new one.
IBefore installing new oxygen sensor, clean exhaust sys-
tem threads using Oxygen Sensor Thread Cleaner tool
and approved anti-seize lubricant.
DTC P0133 HEATED OXYGEN SENSOR 1 (FRONT)
(RESPONSE MONITORING)QG16I18DE
Component Inspection (Cont'd)
EC-159

DescriptionNLEC0136SYSTEM DESCRIPTIONNLEC0136S01
Sensor Input Signal to ECMECM func-
tionActuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS)Engine speedHeated
oxygen
sensor 1
heater
(front) con-
trolHeated oxygen sensor 1 heater
(front)
The ECM performs ON/OFF control of the heated oxygen sensor 1 heater (front) corresponding to the engine
operating condition.
OPERATIONNLEC0136S02
Engine speed Heated oxygen sensor 1 heater (front)
Above 3,200 rpm OFF
Below 3,200 rpm ON
CONSULT-II Reference Value in Data Monitor
Mode
NLEC0137Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
HO2S1 HTR (B1)IEngine speed: Below 3,200 rpm ON
IEngine speed: Above 3,200 rpm OFF
ECM Terminals and Reference ValueNLEC0138Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TERMI-
NAL NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
4LHeated oxygen sensor 1
heater (front)[Engine is running]
IEngine speed is below 3,200 rpm.Approximately 0V
[Engine is running]
IEngine speed is above 3,200 rpm.BATTERY VOLTAGE
(11 - 14V)
On Board Diagnosis LogicNLEC0139
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0135
0135IThe current amperage in the heated oxygen sensor 1
heater (front) circuit is out of the normal range.
[An improper voltage drop signal is sent to ECM through
the heated oxygen sensor 1 heater (front).]IHarness or connectors
(The heated oxygen sensor 1 heater (front) cir-
cuit is open or shorted.)
IHeated oxygen sensor 1 heater (front)
DTC P0135 HEATED OXYGEN SENSOR 1 (FRONT)
HEATERQG16I18DE
Description
EC-166

Component DescriptionNLEC0162The heated oxygen sensor 2 (rear), after three way catalyst, moni-
tors 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
NLEC0163Specification 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 ValueNLEC0164Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the 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 LogicNLEC0165The 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
DTC P0139 HEATED OXYGEN SENSOR 2 (REAR)
(RESPONSE MONITORING)QG16I18DE
Component Description
EC-188

DTC Confirmation ProcedureNLEC0598CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If ªDTC Confirmation Procedure º has been previously conducted,
always turn ignition switch ªOFFº and wait at least 9 seconds
before conducting the next test.
TESTING CONDITION:
Never stop engine during this procedure. If the engine is
stopped, retry this procedure from step 2.
With CONSULT-II
NOTE:
The figure on the left will be displayed on the CONSULT-II
screen when you start the DTC Work Support. Ignore the first
figure and start the test.
ªCOMPLETEDº will be displayed on the screen as the second
figure when the test is completed properly.
1) Start engine and warm it up to normal operating temperature.
2) Turn ignition switch ªOFFº and wait at least 9 seconds.
3) Turn ignition switch ªONº and select ªHO2S2 (B1) P0139º of
ªHO2S2º in ªDTC WORK SUPPORTº mode with CONSULT-II.
4) Touch ªSTARTº.
5) Start engine and let it idle for at least 30 seconds.
6) Rev engine up to 2,000 rpm 2 or 3 times quickly under no load.
If ªCOMPLETEDº appears on CONSULT-II screen, go to step
10.
If ªCOMPLETEDº does not appear on CONSULT-II screen, go
to the following step.
7) Drive vehicle at a speed of more than 70 km/h (43 MPH) for 2
consecutive minutes.
8) Additionally, ªCOMPLETEDº will be displayed on the CON-
SULT-II screen when the accelerator pedal is completely
released after the vehicle is driven for 60 seconds or more
under the following conditions.
(It will take approximately 5 seconds.)
ENG SPEED 1,500 - 3,600 rpm
Vehicle speed Above 70 km/h (43 MPH)
B/FUEL SCHDL Above 2.7 msec
COOLAN TEMP/S 70 - 105ÉC (158 - 221ÉF)
Selector lever 4th gear position
NOTE:
IIf ªCOMPLETEDº appears on CONSULT-II screen, go to
step 10.
IIf ªCOMPLETEDº does not appear on CONSULT-II screen,
go to the following step.
9) Stop the vehicle and let it idle until ªCOMPLETEDº is displayed
on the CONSULT-II screen. (It will take 6 minutes at the most.)
NOTE:
If ªCOMPLETEDº is not displayed after 6 minutes, retry from
step 2.
10) Make sure that ªOKº is displayed after touching ªSELF-DIAG
RESULTSº.
If ªNGº is displayed, refer to ªDiagnostic Procedureº, EC-QG-
192.
SEF688X
SEF690X
DTC P0139 HEATED OXYGEN SENSOR 2 (REAR)
(RESPONSE MONITORING)QG16I18DE
DTC Confirmation Procedure
EC-189

Overall Function CheckNLEC0599Use this procedure to check the overall function of the rear heated
oxygen sensor circuit. During this check, a 1st trip DTC might not
be confirmed.
Without CONSULT-II
1) Start engine and drive vehicle at a speed of more than 70 km/h
(43 MPH) for 2 consecutive minutes.
2) Stop vehicle with engine running.
3) Set voltmeter probes between ECM terminals 63 (HO2S2 sig-
nal) and engine ground.
4) Check the voltage when revving up to 4,000 rpm under no load
at least 10 times.
(Depress and release accelerator pedal as soon as possible.)
The voltage should change at more than 0.06V for 1 sec-
ond during this procedure.
If the voltage can be confirmed in step 4, step 5 is not
necessary.
5) Keep vehicle at idling for 10 minutes, then check the voltage.
Or check the voltage when coasting from 80 km/h (50 MPH)
in 3rd gear position.
The voltage should change at more than 0.06V for 1 sec-
ond during this procedure.
6) If NG, go to ªDiagnostic Procedureº, EC-QG-192.
SEF032X
DTC P0139 HEATED OXYGEN SENSOR 2 (REAR)
(RESPONSE MONITORING)QG16I18DE
Overall Function Check
EC-190