Page 649 of 3051
MODELS WITH ECM IN CABINNLEC0141S04
YEC878
DTC P0135 HEATED OXYGEN SENSOR 1 (FRONT) HEATERQG18DE
Wiring Diagram (Cont'd)
EC-224
Page 650 of 3051

Diagnostic ProcedureNLEC0142
1 CHECK POWER SUPPLY
1. Turn ignition switch ªOFFº.
2. Disconnect heated oxygen sensor 1 (front) harness connector.
SEF012XA
3. Turn ignition switch ªONº.
4. Check voltage between terminal 1 and ground with CONSULT-II or tester.
SEF934X
OK or NG
OK©GO TO 3.
NG©GO TO 2.
2 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors F38, M50 (where fitted)
+Harness connectors F44, M72 (where fitted)
+10A fuse
+Harness for open or short between heated oxygen sensor 1 (front) and fuse
©Repair harness or connectors.
3 CHECK OUTPUT SIGNAL CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connector.
3. Check harness continuity between heated oxygen sensor 1 (front) harness connector terminal 3 and ECM terminal 4.
Refer to wiring diagram.
Continuity should exist.
4. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 4.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
DTC P0135 HEATED OXYGEN SENSOR 1 (FRONT) HEATERQG18DE
Diagnostic Procedure
EC-225
Page 651 of 3051
4 CHECK HEATED OXYGEN SENSOR 1 HEATER (FRONT)
Refer to ªComponent Inspectionº, EC-226.
OK or NG
OK©GO TO 5.
NG©Replace heated oxygen sensor 1 (front).
5 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-145.
©INSPECTION END
SEF935X
Component InspectionNLEC0143HEATED OXYGEN SENSOR 1 HEATER (FRONT)NLEC0143S01Check resistance between terminals 3 and 1.
Resistance: 2.3 - 4.3Wat 25ÉC (77ÉF)
Check continuity between terminals 2 and 1, 3 and 2.
Continuity should not exist.
If NG, replace the heated oxygen sensor 1 (front).
CAUTION:
+Discard 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.
+Before installing new oxygen sensor, clean exhaust sys-
tem threads using Oxygen Sensor Thread Cleaner tool
and approved anti-seize lubricant.
DTC P0135 HEATED OXYGEN SENSOR 1 (FRONT) HEATERQG18DE
Diagnostic Procedure (Cont'd)
EC-226
Page 652 of 3051

SEF327R
Component DescriptionNLEC0144The 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
NLEC0145Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 (B1)
+Engine: 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 ValueNLEC0146Specification 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]
+After warming up to normal operating tempera-
ture and engine speed is 3,000 rpm0 - Approximately 1.0V
SEF258VA
On Board Diagnosis LogicNLEC0147The 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
0137+The minimum voltage from the sensor does not reach
the specified voltage.+Harness or connectors
(The sensor circuit is open or shorted.)
+Heated oxygen sensor 2 (rear)
+Fuel pressure
+Injectors
DTC P0137 HEATED OXYGEN SENSOR 2 (REAR)
(MIN. VOLTAGE MONITORING)
QG18DE
Component Description
EC-227
Page 653 of 3051

SEF833Y
SEF834Y
SEF835Y
DTC Confirmation ProcedureNLEC0594CAUTION:
Always drive vehicle at a safe speed.
NOTE:
+ªCOMPLETEDº will appear on CONSULT-II screen when all
tests ªCOND1º, ªCOND2º and ªCOND3º are completed.
+If ªDTC Confirmation Procedureº 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 in ªProcedure for
COND1º.
With CONSULT-II
Procedure for COND1
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) P0137º 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
2 in ªProcedure for COND3º.
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) When the following conditions are met, ªTESTINGº will be dis-
played at ªCOND1º on the CONSULT-II screen. Maintain the
conditions continuously until ªTESTINGº changes to ªCOM-
PLETEDº. (It will take approximately 60 seconds.)
ENG SPEED 1,500 - 3,600 rpm
Vehicle speed Above 70 km/h (43 MPH)
Selector lever Suitable position
NOTE:
+If ªTESTINGº is not displayed after 5 minutes, retry from
step 2 in ªProcedure for COND1º.
+If ªCOMPLETEDº already appears at ªCOND2º on CON-
SULT-II screen before ªProcedure for COND2º is
conducted, it is unnecessary to conduct step 1 in ªProce-
dure for COND2º.
SEF836Y
Procedure for COND2
1) While driving, release accelerator pedal completely with 4th
gear position from the above condition [step 8] until ªINCOM-
PLETEº at ªCOND2º on CONSULT-II screen has turned to
ªCOMPLETEDº. (It will take approximately 4 seconds.)
NOTE:
If ªCOMPLETEDº already appears at ªCOND3º on CONSULT-II
screen before ªProcedure for COND3º is conducted, it is
unnecessary to conduct step 1 in ªProcedure for COND3º.
DTC P0137 HEATED OXYGEN SENSOR 2 (REAR)
(MIN. VOLTAGE MONITORING)
QG18DE
On Board Diagnosis Logic (Cont'd)
EC-228
Page 654 of 3051

SEF661Y
Procedure for COND3
1) Stop vehicle and let it idle until ªINCOMPLETEº of ªCOND3º on
CONSULT-II screen has turned to ªCOMPLETEDº. (It will take
a maximum of approximately 6 minutes.)
2) Make sure that ªOKº is displayed after touching ªSELF-DIAG
RESULTSº. If ªNGº is displayed, refer to ªDiagnostic
Procedureº, EC-232.
SEF032X
Overall Function CheckNLEC0595Use 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 engine up to 4,000 rpm under
no load at least 10 times.
(Depress and release accelerator pedal as soon as possible.)
The voltage should be below 0.56V at least once 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 be below 0.56V at least once during
this procedure.
6) If NG, go to ªDiagnostic Procedureº, EC-232.
DTC P0137 HEATED OXYGEN SENSOR 2 (REAR)
(MIN. VOLTAGE MONITORING)
QG18DE
DTC Confirmation Procedure (Cont'd)
EC-229
Page 655 of 3051
Wiring DiagramNLEC0150MODELS WITH ECM IN ENGINE COMPARTMENTNLEC0150S03
YEC693
DTC P0137 HEATED OXYGEN SENSOR 2 (REAR)
(MIN. VOLTAGE MONITORING)
QG18DE
Wiring Diagram
EC-230
Page 656 of 3051
MODELS WITH ECM IN CABINNLEC0150S04
YEC879
DTC P0137 HEATED OXYGEN SENSOR 2 (REAR)
(MIN. VOLTAGE MONITORING)
QG18DE
Wiring Diagram (Cont'd)
EC-231