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DTC P0138, P0158 HO2S2PFP:226A0
Component DescriptionNBS003ON
The heated oxygen sen INFINITI FX35 2006 Service Manual DTC P0138, P0158 HO2S2 EC-281
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DTC P0138, P0158 HO2S2PFP:226A0
Component DescriptionNBS003ON
The heated oxygen sen](/manual-img/42/57019/w960_57019-1664.png)
DTC P0138, P0158 HO2S2 EC-281
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DTC P0138, P0158 HO2S2PFP:226A0
Component DescriptionNBS003ON
The heated oxygen sensor 2 (HO2S2), after three way catalyst 1,
monitors the oxygen level in the exhaust gas on each bank.
Even if switching characteristics of the air fuel ratio (A/F) sensor 1
are shifted, the air-fuel ratio is controlled to stoichiometric, by the sig-
nal from the heated oxygen sensor 2.
This sensor is made of ceramic zirconia. The zirconia generates volt-
age from approximately 1V in richer conditions to 0V in leaner condi-
tions.
Under normal conditions the heated oxygen sensor 2 is not used for
engine control operation.
CONSULT-II Reference Value in Data Monitor ModeNBS003OO
Specification data are reference values.
On Board Diagnosis LogicNBS004M8
The heated oxygen sensor 2 has a much longer switching time between rich and lean than the air fuel ratio (A/
F) sensor 1. The oxygen storage capacity of the three way catalyst 1 causes the longer switching time.
MALFUNCTION A
To judge the malfunctions of heated oxygen sensor 2, ECM monitors
whether the voltage is unusually high during the various driving con-
dition such as fuel-cut.
MALFUNCTION B
To judge the malfunctions of heated oxygen sensor 2, ECM monitors
whether the minimum voltage of sensor is sufficiently low during the
various driving condition such as fuel-cut.
SEF327R
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 (B1)
HO2S2 (B2)
Revving engine from idle to 3,000 rpm quickly after the following condi-
tions are met
–Engine: After warming up
–Keeping the engine speed between 3,500 and 4,000 rpm for 1 minute and
at idle for 1 minute under no load 0 - 0.3V
←→ Approx. 0.6 -
1.0V
HO2S2 MNTR (B1)
HO2S2 MNTR (B2) LEAN
←→ RICH
PBIB1848E
PBIB2376E
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![INFINITI FX35 2006 Service Manual EC-282
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DTC P0138, P0158 HO2S2
Revision: 2006 December 2006 FX35/FX45
DTC Confirmation ProcedureNBS004M9
Perform PROCEDURE FOR MALFUNCTION A first.
If DTC cannot be confirmed, perform PROCEDU INFINITI FX35 2006 Service Manual EC-282
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DTC P0138, P0158 HO2S2
Revision: 2006 December 2006 FX35/FX45
DTC Confirmation ProcedureNBS004M9
Perform PROCEDURE FOR MALFUNCTION A first.
If DTC cannot be confirmed, perform PROCEDU](/manual-img/42/57019/w960_57019-1665.png)
EC-282
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DTC P0138, P0158 HO2S2
Revision: 2006 December 2006 FX35/FX45
DTC Confirmation ProcedureNBS004M9
Perform PROCEDURE FOR MALFUNCTION A first.
If DTC cannot be confirmed, perform PROCEDURE FOR MALFUNCTION B.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
PROCEDURE FOR MALFUNCTION A
With CONSULT-II
1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-II.
2. Start engine and warm it up to the normal operating tempera- ture.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 2 minutes.
6. If 1st trip DTC is detected, go to EC-282, "
PROCEDURE FOR
MALFUNCTION A" .
With GST
Follow the procedure “With CONSULT-II” above.
PROCEDURE FOR MALFUNCTION B
With CONSULT-II
TESTING CONDITION:
For better results, perform “DTC WORK SUPPORT” at a temperature of 0 to 30 °C (32 to 86 °F).
1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-II.
2. Start engine and warm it up to the normal operating tempera- ture.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.
6. Make sure that “COOLAN TEMP/S” indicates more than 70 °C
(158 °F).
If not, warm up engine and go to next step when “COOLAN
TEMP/S” indication reaches to 70 °C (158 °F).
7. Open engine hood.
8. Select “HO2S2 (B1) P1146” (for DTC P0138) or “HO2S2 (B2) P1166” (for DTC P0158) of “HO2S2” in “DTC WORK SUPPORT” mode with CONSULT-II.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0138
0138
(Bank 1)
Heated oxygen sensor
2 circuit high voltage A)
An excessively high voltage from the sen-
sor is sent to ECM.
Harness or connectors
(Heated oxygen sensor 2 circuit is
open or shorted)
Heated oxygen sensor 2
P0158
0158
(Bank 2) B)
The minimum voltage from the sensor is
not reached to the specified voltage.
Harness or connectors
(Heated oxygen sensor 2 circuit is
open or shorted)
Heated oxygen sensor 2
Fuel pressure
Fuel injector
SEF174Y
SEF174Y
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![INFINITI FX35 2006 Service Manual DTC P0138, P0158 HO2S2 EC-283
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9. Start engine and following the instruction of CONSULT-II. NOTE:
It will take a INFINITI FX35 2006 Service Manual DTC P0138, P0158 HO2S2 EC-283
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9. Start engine and following the instruction of CONSULT-II. NOTE:
It will take a](/manual-img/42/57019/w960_57019-1666.png)
DTC P0138, P0158 HO2S2 EC-283
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9. Start engine and following the instruction of CONSULT-II. NOTE:
It will take at most 10 minutes until “COMPLETED” is displayed.
10. Make sure that “OK” is displayed after touching “SELF-DIAG RESULTS”. If “NG” is displayed, refer to EC-282, "
PROCEDURE FOR MALFUNCTION B" .
If “CAN NOT BE DIAGNOSED” is displayed, perform the following.
a. Turn ignition switch OFF and leave the vehicle in a cool place (soak the vehicle).
b. Return to step 1.
Overall Function CheckNBS004MA
PROCEDURE FOR MALFUNCTION B
Use this procedure to check the overall function of the heated oxygen sensor 2 circuit. During this check, a 1st
trip DTC might not be confirmed.
With GST
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
4. Let engine idle for 1 minute.
5. Set voltmeter probes between ECM terminal 55 [HO2S2 (B2) signal] or 74 [HO2S2 (B1) signal] and ground.
6. 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 be below 0.18V at least once during this
procedure.
If the voltage can be confirmed in step 6, step 7 is not nec-
essary.
7. Keep vehicle at idling for 10 minutes, then check the voltage. Or check the voltage when coasting from 80 km/h (50 MPH) in D
position.
The voltage should be below 0.18V at least once during this
procedure.
8. If NG, go to EC-282, "
PROCEDURE FOR MALFUNCTION B" .
PBIB2372E
PBIB1607E
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EC-284
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DTC P0138, P0158 HO2S2
Revision: 2006 December 2006 FX35/FX45
Wiring DiagramNBS003OR
BANK 1
TBWM1382E
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![INFINITI FX35 2006 Service Manual DTC P0138, P0158 HO2S2 EC-285
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Specification data are reference values and are measured between each terminal and INFINITI FX35 2006 Service Manual DTC P0138, P0158 HO2S2 EC-285
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Specification data are reference values and are measured between each terminal and](/manual-img/42/57019/w960_57019-1668.png)
DTC P0138, P0158 HO2S2 EC-285
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Specification 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.
TER-
MINAL NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
25 P Heated oxygen sensor 2
heater (bank 1) [Engine is running]
Engine speed: Below 3,600 rpm after the
following conditions are met
–Engine: After warming up
–Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for 1
minute under no load 0 - 1.0V
[Ignition switch: ON]
Engine stopped
[Engine is running]
Engine speed: Above 3,600 rpm BATTERY VOLTAGE
(11 - 14V)
74 LG/B Heated oxygen sensor 2
(bank 1) [Engine is running]
Revving engine from idle to 3,000 rpm
quickly after the following conditions are met
–Engine: After warming up
–After keeping the engine speed between
3,500 and 4,000 rpm for 1 minute and at idle
for 1 minute under no load 0 - Approximately 1.0V
78 B/R Sensor ground
(Heated oxygen sensor) [Engine is running]
Warm-up condition
Idle speed
Approximately 0V
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EC-286
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DTC P0138, P0158 HO2S2
Revision: 2006 December 2006 FX35/FX45
BANK 2
TBWM1383E
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Specification data are reference values and are measured between each terminal and](/manual-img/42/57019/w960_57019-1670.png)
DTC P0138, P0158 HO2S2 EC-287
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Specification 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.
Diagnostic ProcedureNBS003OS
PROCEDURE FOR MALFUNCTION A
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screw on the body. Refer to EC-154, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
6R Heated oxygen sensor 2
heater (bank 2) [Engine is running]
Engine speed: Below 3,600 rpm after the
following conditions are met
–Engine: After warming up
–Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for 1
minute under no load 0 - 1.0V
[Ignition switch: ON]
Engine stopped
[Engine is running]
Engine speed: Above 3,600 rpm BATTERY VOLTAGE
(11 - 14V)
55 W/R Heated oxygen sensor 2
(bank 2) [Engine is running]
Revving engine from idle to 3,000 rpm
quickly after the following conditions are met
–Engine: After warming up
–After keeping the engine speed between
3,500 and 4,000 rpm for 1 minute and at idle
for 1 minute under no load 0 - Approximately 1.0V
78 B/R Sensor ground
(Heated oxygen sensor) [Engine is running]
Warm-up condition
Idle speed
Approximately 0V
PBIB2625E
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![INFINITI FX35 2006 Service Manual EC-288
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DTC P0138, P0158 HO2S2
Revision: 2006 December 2006 FX35/FX45
2. CHECK HEATED OXYGEN SENSOR 2 GROUND CIRCUIT FOR OPEN AND SHORT
1. Disconnect heated oxygen sensor 2 harness connector. INFINITI FX35 2006 Service Manual EC-288
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DTC P0138, P0158 HO2S2
Revision: 2006 December 2006 FX35/FX45
2. CHECK HEATED OXYGEN SENSOR 2 GROUND CIRCUIT FOR OPEN AND SHORT
1. Disconnect heated oxygen sensor 2 harness connector.](/manual-img/42/57019/w960_57019-1671.png)
EC-288
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Revision: 2006 December 2006 FX35/FX45
2. CHECK HEATED OXYGEN SENSOR 2 GROUND CIRCUIT FOR OPEN AND SHORT
1. Disconnect heated oxygen sensor 2 harness connector.
2. Disconnect ECM harness connector.
3. Check harness continuity between HO2S2 terminal 4 and ECM terminal 78.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to ground or short to power in harness or connectors.
3. CHECK HEATED OXYGEN SENSOR 2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal and HO2S2 terminal as follows. Refer to Wiring Diagram.
2. Check harness continuity between the following terminals and ground. Refer to Wiring Diagram.
3. Also check harness for 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.
4. CHECK HEATED OXYGEN SENSOR 2 CONNECTOR FOR WATER
Check connectors for water.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace harness or connectors.
5. CHECK HEATED OXYGEN SENSOR 2
Refer to EC-291, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Replace malfunctioning heated oxygen sensor 2. Continuity should exist.
PBIB1576E
DTC
Terminals
Bank
ECM Sensor
P0138 74 1 1
P0158 55 1 2
Continuity should exist.
DTC Terminals
Bank
ECM Sensor
P0138 74 1 1
P0158 55 1 2
Continuity should not exist.
Water should not exist.