Page 1169 of 3051

SEF646Y
SEF217YA
Component InspectionNLEC1454HEATED OXYGEN SENSOR 1 (FRONT)NLEC1454S01With 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.
+ªHO2S1 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
+ªHO2S1 (B1)º voltage goes above 0.6V at least once.
+ªHO2S1 (B1)º voltage goes below 0.3V at least once.
+ªHO2S1 (B1)º voltage never exceeds 1.0V.
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.
SEF648Y
SEF011X
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.
+The voltage fluctuates between 0 to 0.3V and 0.6 to 1.0V more
than five times within 10 seconds.
1 time: 0 - 0.3V®0.6 - 1.0V®0 - 0.3V
2 times: 0 - 0.3V®0.6 - 1.0V®0 - 0.3V®0.6 - 1.0V®0
- 0.3V
DTC P0134 HEATED OXYGEN SENSOR 1 (FRONT)
(HIGH VOLTAGE)
SR20DE
Component Inspection
EC-744
Page 1170 of 3051
+The maximum voltage is over 0.6V at least one time.
+The minimum voltage is below 0.3V at least one time.
+The voltage never exceeds 1.0V.
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 P0134 HEATED OXYGEN SENSOR 1 (FRONT)
(HIGH VOLTAGE)
SR20DE
Component Inspection (Cont'd)
EC-745
Page 1171 of 3051

DescriptionNLEC1455SYSTEM DESCRIPTIONNLEC1455S01
Sensor Input Signal to ECMECM func-
tionActuator
Camshaft position sensor 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.
OPERATIONNLEC1455S02
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
NLEC1456Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
HO2S1 HTR (B1)+Engine speed: Below 3,200 rpm ON
+Engine speed: Above 3,200 rpm OFF
ECM Terminals and Reference ValueNLEC1457Specification 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]
+Engine speed is below 3,200 rpm.Approximately 0V
[Engine is running]
+Engine speed is above 3,200 rpm.BATTERY VOLTAGE
(11 - 14V)
On Board Diagnosis LogicNLEC1458
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0135+The 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).]+Harness or connectors
(The heated oxygen sensor 1 heater (front) cir-
cuit is open or shorted.)
+Heated oxygen sensor 1 heater (front)
DTC P0135 HEATED OXYGEN SENSOR 1 (FRONT) HEATERSR20DE
Description
EC-746
Page 1172 of 3051

DTC Confirmation ProcedureNLEC1459NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch ªOFFº and wait at least 10 seconds
before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that bat-
tery voltage is between 10.5V and 16V at idle.
SEF058Y
With CONSULT-II
1) Turn ignition switch ªONº and select ªDATA MONITORº mode
with CONSULT-II.
2) Start engine and run it for at least 6 seconds at idle speed.
3) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-750.
With GST
1) Start engine and run it for at least 6 seconds at idle speed.
2) Turn ignition switch ªOFFº and wait at least 10 seconds.
3) Start engine and run it for at least 6 seconds at idle speed.
4) Select ªMODE 3º with GST.
5) If DTC is detected, go to ªDiagnostic Procedureº, EC-750.
+When using GST, ªDTC Confirmation Procedureº should
be performed twice as much as when using CONSULT-II
because GST cannot display MODE 7 (1st trip DTC) con-
cerning this diagnosis. Therefore, using CONSULT-II is
recommended.
DTC P0135 HEATED OXYGEN SENSOR 1 (FRONT) HEATERSR20DE
DTC Confirmation Procedure
EC-747
Page 1173 of 3051
Wiring DiagramNLEC1460MODELS WITH ECM IN ENGINE COMPARTMENTNLEC1460S03
YEC692
DTC P0135 HEATED OXYGEN SENSOR 1 (FRONT) HEATERSR20DE
Wiring Diagram
EC-748
Page 1174 of 3051
MODELS WITH ECM IN CABINNLEC1460S04
YEC917
DTC P0135 HEATED OXYGEN SENSOR 1 (FRONT) HEATERSR20DE
Wiring Diagram (Cont'd)
EC-749
Page 1175 of 3051

Diagnostic ProcedureNLEC1461
1 CHECK POWER SUPPLY
1. Turn ignition switch ªOFFº.
2. Disconnect heated oxygen sensor 1 (front) harness connector.
SEF774Z
3. Turn ignition switch ªONº.
4. Check voltage between HO2S1 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 M72, F44 (where fitted)
+10A fuse
+Harness for open or short between heated oxygen sensor 1 (front) and fuse
©Repair harness or connectors.
3 CHECK OUTPUT CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connector.
3. Check harness continuity between HO2S1 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) HEATERSR20DE
Diagnostic Procedure
EC-750
Page 1176 of 3051
4 CHECK HEATED OXYGEN SENSOR 1 HEATER (FRONT)
Refer to ªComponent Inspectionº, EC-751.
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-670.
©INSPECTION END
SEF935X
Component InspectionNLEC1462HEATED OXYGEN SENSOR 1 HEATER (FRONT)NLEC1462S01Check 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) HEATERSR20DE
Diagnostic Procedure (Cont'd)
EC-751