2008 INFINITI FX35 ESP

DTC P0127 IAT SENSOREC-207
< SERVICE INFORMATION > [VQ35DE]
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DTC P0127 IAT SENSOR
Component DescriptionINFOID:0000000001326034
The intake air temperature sensor is
built into mass air flow sensor.
The sensor detects intake air temperature and transmits a signal to
the ECM.
The temperature sensing unit uses a thermistor which is sensitive to
the change in temperature. Electric al resistance of the thermistor
decreases in response to the temperature rise.

*: This data is reference values and is measured between ECM terminal 34 (Intake
air temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output
voltage. Doing so may result in damage to the ECM's transistor.
Use a ground other than ECM te rminals, such as the ground.
On Board Diagnosis LogicINFOID:0000000001326035
DTC Confirmation ProcedureINFOID:0000000001326036
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
CAUTION:
Always drive vehicle at a safe speed.
TESTING CONDITION:
This test may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a road
test is expected to be easier, it is unnecessary to lift the vehicle.
WITH CONSULT-III
1. Wait until engine coolant temperature is less than 90 °C (194 °F)
a. Turn ignition switch ON.
b. Select “DATA MONITOR” mode with CONSULT-III.
c. Check the engine coolant temperature.
d. If the engine coolant temperature is not less than 90 °C (194 °F), turn ignition switch OFF and cool down
engine.
 Perform the following steps before engine coolant temperature is above 90 °C (194 °F).
PBIB1604E
Intake air temperature
°C ( °F) Voltage* V Resistance k
Ω
25 (77) 3.30 1.800 - 2.200
80 (176) 1.22 0.283 - 0.359
SEF012P
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0127
0127 Intake air temperature
too high Rationally incorrect voltage from the sensor is
sent to ECM, compared with the voltage signal
from engine coolant temperature sensor.  Harness or connectors
(Intake air temperature sensor circuit is
open or shorted)
 Intake air temperature sensor
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EC-236
< SERVICE INFORMATION >[VQ35DE]
DTC P0133, P0153
A/F SENSOR 1
DTC P0133, P0153 A/F SENSOR 1
Component DescriptionINFOID:0000000001326067
The air fuel ratio (A/F) sensor 1 is a planar dual-cell limit current sen-
sor. The sensor element of the air fuel ratio (A/F) sensor 1 is the
combination of a Nernst concentration cell (sensor cell) with an oxy-
gen-pump cell, which transports ions. It has a heater in the element.
The sensor is capable of precise measurement = 1, but also in the
lean and rich range. Together with its control electronics, the sensor
outputs a clear, continuous signal throughout a wide range (0.7 <
< air).
The exhaust gas components diffuse through the diffusion gap at the
electrode of the oxygen pump and Nernst concentration cell, where
they are brought to thermodynamic balance.
An electronic circuit controls the pump current through the oxygen-
pump cell so that the composition of the exhaust gas in the diffusion
gap remains constant at = 1. Therefore, the air fuel ratio (A/F) sen-
sor 1 is able to indicate air/fuel ratio by this pumping of current. In
addition, a heater is integrated in the sensor to ensure the required
operating temperature of 700 - 800 °C (1,292 - 1,472 °F).
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001326068
Specification data are reference values.
On Board Diagn osis LogicINFOID:0000000001326069
To judge the malfunction of air fuel ratio (A/F) sensor 1, this diagnosis measures response time of the A/F sig-
nal computed by ECM from the air fuel ratio (A/F) s ensor 1 signal. The time is compensated by engine operat-
ing (speed and load), fuel feedback control constant, and the air fuel ratio (A/F) sensor 1 temperature index.
Judgment is based on whether the com pensated time (the A/F signal cycling time index) is inordinately long or
not.
DTC Confirmation ProcedureINFOID:0000000001326070
NOTE:
SEF579Z
SEF580Z
MONITOR ITEM CONDITION SPECIFICATION
A/F SEN1 (B1)
A/F SEN1 (B2)  Engine: After warming up
Maintaining engine speed at
2,000 rpm Fluctuates around 1.5V
DTC No. Trouble diagnosis name DTC detecting condition Possible Cause
P0133
0133
(Bank 1)
Air fuel ratio (A/F) sensor 1
circuit slow response The response of the A/F signal computed by ECM
from air fuel ratio (A/F) sensor 1 signal takes more
than the specified time.  Harness or connectors
[Air fuel ratio (A/F) sensor 1 circuit is
open or shorted.]
 Air fuel ratio (A/F) sensor 1
 Air fuel ratio (A/F) sensor 1 heater
 Fuel pressure
 Fuel injector
 Intake air leaks
 Exhaust gas leaks
PCV
 Mass air flow sensor
P0153
0153
(Bank 2)
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
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DTC P0139, P0159 HO2S2EC-265
< SERVICE INFORMATION > [VQ35DE]
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DTC P0139, P0159 HO2S2
Component DescriptionINFOID:0000000001326092
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-III Reference Val
ue in Data Monitor ModeINFOID:0000000001326093
Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001326094
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 oxy-
gen storage capacity before the three way catalyst 1 causes the
longer switching time. To judge the malfunctions of heated oxygen
sensor 2, ECM monitors whether the switching response of the sen-
sor's voltage is faster than specified during the various driving condi-
tion such as fuel-cut.
DTC Confirmation ProcedureINFOID:0000000001326095
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-III
TESTING CONDITION:
For better results, perform “DTC WORK SUPPORT” at a temperature of 0 to 30 °C (32 to 86 °F).
SEF327R
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 (B1)
HO2S2 (B2)  Revving engine from idle to 3,000 rpm quickly 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 - 0.3V
←→ Approx. 0.6 - 1.0V
HO2S2 MNTR(B1)
HO2S2 MNTR(B2) LEAN
←→ RICH
SEF302U
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0139
0139
(Bank 1) Heated oxygen sensor 2
circuit slow response It takes more time for the sensor to respond be-
tween rich and lean than the specified time.  Harness or connectors
(Heated oxygen sensor 2 circuit is open
or shorted)
 Heated oxygen sensor 2
 Fuel pressure
 Fuel injector
 Intake air leaks
P0159
0159
(Bank 2)
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
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EC-280
< SERVICE INFORMATION >[VQ35DE]
DTC P0171, P0174 FUEL IN
JECTION SYSTEM FUNCTION
1. Listen for an intake air leak after the mass air flow sensor.
2. Check PCV hose connection.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3.CHECK AIR FUEL RATIO (A/F) SE NSOR 1 INPUT SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect corresponding air fuel ration (A/F) sensor 1 harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between the following terminals. Refer to Wiring Diagram.
5. Check harness continuity between the following terminals and ground. Refer to Wiring Diagram.
6. 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.
4.CHECK FUEL PRESSURE
1. Release fuel pressure to zero. Refer to EC-87, "
Fuel Pressure Check".
2. Install fuel pressure gauge and check fuel pressure. Refer to EC-87, "
Fuel Pressure Check".
A/F sensor 1 terminal ECM terminal
Bank 1 116
275
535
656
Bank 2 176
277
557
658
Continuity should exist.
Bank 1 Bank 2
A/F sensor 1 terminal ECM terminal A/F sensor 1 terminal ECM terminal 116176
275277
535557
656658
Continuity should not exist.
PBIB2190E
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EC-290
< SERVICE INFORMATION >[VQ35DE]
DTC P0172, P0175 FUEL IN
JECTION SYSTEM FUNCTION
Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3.CHECK AIR FUEL RATIO (A/F) SE NSOR 1 INPUT SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect corresponding A/F sensor 1 harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between the following terminals. Refer to Wiring Diagram.
5. Check harness continuity between the following terminals and ground. Refer to Wiring Diagram.
6. 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.
4.CHECK FUEL PRESSURE
1. Release fuel pressure to zero. Refer to EC-87, "
Fuel Pressure Check".
2. Install fuel pressure gauge and check fuel pressure. Refer to EC-87, "
Fuel Pressure Check".
Bank 1A/F sensor 1 terminal ECM terminal
116
275
535
656
Bank 2 176
277
557
658
Continuity should exist.
Bank 1 Bank 2
A/F sensor 1 terminal ECM terminal A/F sensor 1 terminal ECM terminal 116176
275277
535557
656658
Continuity should not exist.
PBIB2190E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

EC-302
< SERVICE INFORMATION >[VQ35DE]
DTC P0222, P0223 TP SENSOR
DTC P0222, P0223 TP SENSOR
Component DescriptionINFOID:0000000001326123
Electric throttle control actuator
consists of throttle control motor,
throttle position (TP) sensor, et c. The throttle position sensor
responds to the throttle valve movement.
The throttle position sensor has two sensors. These sensors are a
kind of potentiometers which transform the throttle valve position into
output voltage, and emit the voltage signal to the ECM. In addition,
these sensors detect the opening and closing speed of the throttle
valve and feed the voltage signals to the ECM. The ECM judges the
current opening angle of the throttle valve from these signals and the
ECM controls the throttle control motor to make the throttle valve
opening angle properly in response to driving condition.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001326124
Specification data are reference values.
*: Throttle position sensor 2 signal is converted by ECM internally. Thus, it differs from ECM terminal voltage signal.
On Board Diagn osis LogicINFOID:0000000001326125
These self-diagnoses have the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureINFOID:0000000001326126
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 8V at idle.
1. Start engine and let it idle for 1 second.
2. Check DTC.
3. If DTC is detected, go to EC-304, "
Diagnosis Procedure".
PBIB0145E
MONITOR ITEM CONDITION SPECIFICATION
TP SEN 1-B1
TP SEN 2-B1*  Ignition switch: ON
(Engine stopped)
 Selector lever: D Accelerator pedal:
Fully released More than 0.36V
Accelerator pedal: Fully depressed Less than 4.75V
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0222
0222 Throttle position sensor
1 circuit low input An excessively low voltage from the TP sensor
1 is sent to ECM.  Harness or connectors
(TP sensor 1 circuit is open or shorted.)
(APP sensor 2 circuit is shorted.)
 Electric throttle control actuator (TP sensor 1)
 Accelerator pedal position sensor. (APP sensor 2)
P0223
0223
Throttle position sensor
1 circuit high input An excessively high voltage from the TP sensor
1 is sent to ECM.
Engine operation condition in fail-safe mode
The ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle position to be within +10
degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal condition.
So, the acceleration will be poor.
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
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DTC P0447 EVAP CANISTER VENT CONTROL VALVE
EC-361
< SERVICE INFORMATION > [VQ35DE]
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DTC P0447 EVAP CANISTER
VENT CONTROL VALVE
Component DescriptionINFOID:0000000001326185
The EVAP canister vent control valve is located on the EVAP canis-
ter and is used to seal the canister vent.
This solenoid valve responds to signals from the ECM. When the
ECM sends an ON signal, the coil in the solenoid valve is energized.
A plunger will then move to seal the canister vent. The ability to seal
the vent is necessary for the on board diagnosis of other evaporative
emission control system components.
This solenoid valve is used only for diagnosis, and usually remains
opened.
When the vent is closed, under normal purge conditions, the evapo-
rative emission control system is depressurized and allows EVAP
Control System diagnosis.
CONSULT-III Reference Val ue in Data Monitor ModeINFOID:0000000001326186
Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001326187
DTC Confirmation ProcedureINFOID:0000000001326188
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, conf irm battery voltage is more than 11V at idle.
1. Start engine and wait at least 8 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-363, "
Diagnosis Procedure".
PBIB1263E
PBIB1611E
MONITOR ITEM CONDITION SPECIFICATION
VENT CONT/V  Ignition switch: ON OFF
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0447
0447 EVAP canister vent con-
trol valve circuit open An improper voltage signal is sent to ECM
through EVAP canister vent control valve.  Harness or connectors
(EVAP canister vent control valve circuit
is open or shorted.)
 EVAP canister vent control valve
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
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EC-366
< SERVICE INFORMATION >[VQ35DE]
DTC P0448 EVAP CANISTER VENT CONTROL VALVE
DTC P0448 EVAP CANISTER VENT CONTROL VALVE
Component DescriptionINFOID:0000000001326192
The EVAP canister vent control
valve is located on the EVAP canis-
ter and is used to seal the canister vent.
This solenoid valve responds to signals from the ECM. When the
ECM sends an ON signal, the coil in the solenoid valve is energized.
A plunger will then move to seal the canister vent. The ability to seal
the vent is necessary for the on board diagnosis of other evaporative
emission control system components.
This solenoid valve is used only for diagnosis, and usually remains
opened.
When the vent is closed, under normal purge conditions, the evapo-
rative emission control system is depressurized and allows EVAP
Control System diagnosis.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001326193
Specification data are reference values.
On Board Diagn osis LogicINFOID:0000000001326194
DTC Confirmation ProcedureINFOID:0000000001326195
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
1. Turn ignition switch ON and wait at least 5 seconds.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and let it idle for at least 1 minute.
4. Repeat next procedures three times.
a. Increase the engine speed up to 3,000 to 3,500 rpm and keep it for 2 minutes and 50 seconds to 3 min- utes.
Never exceed 3 minutes.
b. Fully released accelerator pedal and keep engine idle for about 5 seconds.
PBIB1263E
PBIB1611E
MONITOR ITEM CONDITION SPECIFICATION
VENT CONT/V  Ignition switch: ON OFF
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0448
0448 EVAP canister vent con-
trol valve close EVAP canister vent control valve remains
closed under specified driving conditions.  EVAP canister vent control valve
 EVAP control system pressure sensor
and the circuit
 Blocked rubber tube to EVAP canister vent control valve
 EVAP canister is saturated with water
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