Page 945 of 2267

On Board Diagnosis LogicNCEC0097Under the condition in which the heated oxygen sensor 1 (front)
signal is not input, the ECM circuits will read a continuous approxi-
mately 0.3V. Therefore, for this diagnosis, the time that output
voltage is within 200 to 400 mV range is monitored, and the diag-
nosis checks that this time is not inordinately long.
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0130
0130IThe voltage from the sensor is constantly approx. 0.3V.IHarness or connectors
(The sensor circuit is open or shorted.)
IHeated oxygen sensor 1 (front)
DTC Confirmation ProcedureNCEC0098CAUTION:
Always drive vehicle at a safe speed.
NOTE:
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:
IAlways perform at a temperature above þ10ÉC (14ÉF).
IBefore performing the following procedure, confirm that
battery voltage is more than 11V at idle.
With CONSULT-II
1) Start engine and warm it up to normal operating temperature.
2) Select ªHO2S1 (B1) P0130º of ªHO2S1º in ªDTC WORK SUP-
PORTº mode with CONSULT-II.
3) Touch ªSTARTº.
4) Let it idle for at least 3.5 minutes.
NOTE:
Never raise engine speed above 3,200 rpm after this step. If
the engine speed limit is exceeded, return to step 4.
5) When the following conditions are met, ªTESTINGº will be dis-
played on the CONSULT-II screen. Maintain the conditions
continuously until ªTESTINGº changes to ªCOMPLETEDº. (It
will take approximately 10 to 60 seconds.)
ENG SPEED 1,500 - 3,200 rpm
Vehicle speed 64 - 130 km/h (40 - 81 MPH)
B/FUEL SCHDL 2.4 - 11.0 msec
Selector lever Suitable position
If ªTESTINGº is not displayed after 5 minutes, retry from
step 2.
SEF237U
SEF825Y
SEF826Y
SEF645Y
DTC P0130 HEATED OXYGEN SENSOR 1
(FRONT) (CIRCUIT)SR20DE
On Board Diagnosis Logic
EC-145
Page 946 of 2267
6) Make sure that ªOKº is displayed after touching ªSELF-DIAG
RESULTSº. If ªNGº is displayed, refer to ªDiagnostic
Procedureº, EC-SR-148.
Overall Function CheckNCEC0099Use this procedure to check the overall function of the heated oxy-
gen sensor 1 (front) circuit. During this check, a 1st trip DTC might
not be confirmed.
Without CONSULT-II
1) Start engine and warm it up to normal operating temperature.
2) Set voltmeter probes between ECM terminal 62 (Heated oxy-
gen sensor 1 (front) signal) and engine ground.
3) Check the following with engine speed held at 2,000 rpm con-
stant under no load.
IThe voltage does not remain in the range of 0.2 - 0.4V.
4) If NG, go to ªDiagnostic Procedureº, EC-SR-148.
SEF011X
DTC P0130 HEATED OXYGEN SENSOR 1
(FRONT) (CIRCUIT)SR20DE
Overall Function Check
EC-146
Page 947 of 2267
Wiring DiagramNCEC0100
YEC084A
DTC P0130 HEATED OXYGEN SENSOR 1
(FRONT) (CIRCUIT)SR20DE
Wiring Diagram
EC-147
Page 948 of 2267

Diagnostic ProcedureNCEC0101
1 INSPECTION START
1. Turn ignition switch ªOFFº.
2. Loosen and retighten engine ground screws.
SEF202X3. Disconnect heated oxygen sensor 1 (front) harness connector.
SEF207X
©GO TO 2.
2 CHECK INPUT SIGNAL CIRCUIT
1. Disconnect 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 3.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
3 CHECK HEATED OXYGEN SENSOR 1 (FRONT)
Refer to ªComponent Inspectionº, EC-SR-149.
OK or NG
OK©GO TO 4.
NG©Replace heated oxygen sensor 1 (front).
4 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-SR-114.
©INSPECTION END
Intake manifold
collector
Engine
ground
Heated oxygen sensor 1
(front) harness connector
Heated oxygen
sensor 1 (front)
DTC P0130 HEATED OXYGEN SENSOR 1
(FRONT) (CIRCUIT)SR20DE
Diagnostic Procedure
EC-148
Page 949 of 2267

Component InspectionNCEC0102HEATED OXYGEN SENSOR 1 (FRONT)NCEC0102S01With CONSULT-II
1) Start engine and warm it up to normal operating temperature.
2) Select ªMANU TRIGº and ªHI SPEEDº 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 5 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:
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.
Without CONSULT-II
1) Start engine and warm it up to normal operating temperature.
2) Set voltmeter probes between ECM terminal 62 (Heated oxy-
gen sensor 1 (front) signal) and engine ground.
3) Check the following with engine speed held at 2,000 rpm con-
stant under no load.
IMalfunction indicator goes on more than five times within 10
seconds in Diagnostic Test Mode II (HEATED OXYGEN SEN-
SOR 1 (FRONT) MONITOR).
IThe maximum voltage is over 0.6V at least one time.
IThe minimum voltage is below 0.3V at least one time.
IThe 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.
SEF646Y
SEF647Y
SEF648Y
FR O2 SENSOR
x0.01V-09²99
-02²89
SEF011X
DTC P0130 HEATED OXYGEN SENSOR 1
(FRONT) (CIRCUIT)SR20DE
Component Inspection
EC-149
Page 950 of 2267

Component DescriptionNCEC0103The heated oxygen sensor 1 (front) is placed into the exhaust
manifold. It detects the amount of oxygen in the exhaust gas com-
pared to the outside air. The heated oxygen sensor 1 (front) 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 (front) 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.
CONSULT-II Reference Value in Data Monitor
Mode
NCEC0104Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
HO2S1 (B1)
IEngine: After warming upMaintaining engine speed at 2,000
rpm0 - 0.3V+,Approx. 0.6 - 1.0V
HO2S1 MNTR
(B1)LEAN+,RICH
Changes more than 5 times during
10 seconds.
ECM Terminals and Reference ValueNCEC0105Specification data are reference values and are measured between each terminal and 48 (ECM ground).
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
62 RHeated oxygen sensor
1 (front)[Engine is running]
IAfter warming up to normal operating temperature
and engine speed is 2,000 rpm0 - Approximately 1.0V
SEF008W
SEF463R
SEF288D
DTC P0131 HEATED OXYGEN SENSOR 1
(FRONT) (LEAN SHIFT MONITORING)SR20DE
Component Description
EC-150
Page 951 of 2267

On Board Diagnosis LogicNCEC0106To judge the malfunction, the output from the heated oxygen sen-
sor 1 (front) is monitored to determine whether the ªrichº output is
sufficiently high and whether the ªleanº output is sufficiently low.
When both the outputs are shifting to the lean side, the malfunc-
tion will be detected.
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0131
0131IThe maximum and minimum voltages from the sensor
are not reached to the specified voltages.IHeated oxygen sensor 1 (front)
IHeated oxygen sensor 1 (front) heater
IFuel pressure
IInjectors
IIntake air leaks
DTC Confirmation ProcedureNCEC0107CAUTION:
Always drive vehicle at a safe speed.
NOTE:
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:
IAlways perform at a temperature above þ10ÉC (14ÉF).
IBefore performing the following procedure, confirm that
battery voltage is more than 11V at idle.
With CONSULT-II
1) Start engine and warm it up to normal operating temperature.
2) Stop engine and wait at least 9 seconds.
3) Turn ignition switch ªONº and select ªHO2S1 P0131º of
ªHO2S1º in ªDTC WORK SUPPORTº mode with CONSULT-II.
4) Touch ªSTARTº.
5) Start engine and let it idle for at least 3.5 minutes.
NOTE:
Never raise engine speed above 3,200 rpm after this step. If
the engine speed limit is exceeded, return to step 5.
6) When the following conditions are met, ªTESTINGº will be dis-
played on the CONSULT-II screen. Maintain the conditions
continuously until ªTESTINGº changes to ªCOMPLETEDº. (It
will take approximately 20 seconds or more.)
SEF300U
SEF827Y
SEF828Y
SEF651Y
DTC P0131 HEATED OXYGEN SENSOR 1
(FRONT) (LEAN SHIFT MONITORING)SR20DE
On Board Diagnosis Logic
EC-151
Page 952 of 2267

ENG SPEED 1,800 - 2,900 rpm (CVT)
2,000 - 3,100 rpm (M/T)
Vehicle speed 80 - 120 km/h (50 - 75 MPH)
B/FUEL SCHDL 4.5 - 14.0 msec (CVT)
3.5 - 12.0 msec (M/T)
Selector lever Suitable position
If ªTESTINGº is not displayed after 5 minutes, retry from
step 2.
7) Make sure that ªOKº is displayed after touching ªSELF-DIAG
RESULTSº. If ªNGº is displayed, refer to ªDiagnostic
Procedureº, EC-SR-153.
Overall Function CheckNCEC0108Use this procedure to check the overall function of the heated oxy-
gen sensor 1 (front) circuit. During this check, a 1st trip DTC might
not be confirmed.
Without CONSULT-II
1) Start engine and warm it up to normal operating temperature.
2) Set voltmeter probes between ECM terminal 62 (Heated oxy-
gen sensor 1 (front) signal) and engine ground.
3) Check the following with engine speed held at 2,000 rpm con-
stant under no load.
IThe maximum voltage is over 0.6V at least one time.
IThe minimum voltage is over 0.1V at least one time.
4) If NG, go to ªDiagnostic Procedureº, EC-SR-153.
SEF011X
DTC P0131 HEATED OXYGEN SENSOR 1
(FRONT) (LEAN SHIFT MONITORING)SR20DE
DTC Confirmation Procedure (Cont'd)
EC-152