2004 INFINITI FX35 air intake

EC-860
[VK45DE]
DTC P0127 IAT SENSOR
Revision: 2004 November 2004 FX35/FX45
Component InspectionABS00C2G
INTAKE AIR TEMPERATURE SENSOR
1. Check resistance between intake air temperature sensor termi-
nals 5 and 6 under the following conditions.
2. If NG, replace mass air flow sensor (with intake air temperature
sensor).
Removal and InstallationABS00C2H
MASS AIR FLOW SENSOR
Refer to EM-172, "AIR CLEANER AND AIR DUCT" .
Intake air temperature °C (°F) Resistance kΩ
25 (77) 1.9 - 2.1
SEC266C
SEF012P

DTC P0133, P0153 HO2S1
EC-873
[VK45DE]
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Revision: 2004 November 2004 FX35/FX45
DTC Confirmation ProcedureABS00C2Y
CAUTION:
Always drive vehicle at a safe speed.
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.
TESTING CONDITION:

Always perform at a temperature above −10°C (14°F).

Before 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 10 seconds.
3. Turn ignition switch ON and select “HO2S1 (B1) P0133” or “HO2S1 (B2) P0153” of “HO2S1” in “DTC
WORK SUPPORT” mode with CONSULT-II.
4. Touch “START”.
5. Start engine and let it idle for at least 3 minutes.
NOTE:
Do not raise engine speed above 3,000 rpm after this step. If
the engine speed limit is exceeded, return to step 5.
6. When the following conditions are met, “TESTING” will be dis-
played on the CONSULT-II screen. Maintain the conditions con-
tinuously until “TESTING” changes to “COMPLETED”. (It will
take approximately 40 to 50 seconds.)
If “TESTING” is not displayed after 5 minutes, retry from
step 2.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0133
0133
(Bank 1)
Heated oxygen sensor
1 circuit slow responseThe response of the voltage signal from the
sensor takes more than the specified time.

Harness or connectors
(The sensor circuit is open or shorted)

Heated oxygen sensor 1

Fuel pressure

Fuel injector

Intake air leaks

Exhaust gas leaks

PCV valve

Mass air flow sensor P0153
0153
(Bank 2)
SEF338Z
ENG SPEED 1,350 - 2,900 rpm
VHCL SPEED SE More than 80 km/h (50 MPH)
B/FUEL SCHDL 1.6 - 12.0 msec
Selector lever Suitable position
SEF339Z

DTC P0133, P0153 HO2S1
EC-879
[VK45DE]
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Revision: 2004 November 2004 FX35/FX45
3. CHECK FOR EXHAUST GAS LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before three way catalyst (manifold).
OK or NG
OK >> GO TO 4.
NG >> Repair or replace.
4. CHECK FOR INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace.
SEC502D

DTC P0139, P0159 HO2S2
EC-903
[VK45DE]
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Revision: 2004 November 2004 FX35/FX45
DTC P0139, P0159 HO2S2PFP:226A0
Component DescriptionABS00C3L
The heated oxygen sensor 2, after three way catalyst (manifold),
monitors the oxygen level in the exhaust gas on each bank.
Even if switching characteristics of the heated oxygen sensor 1 are
shifted, the air-fuel ratio is controlled to stoichiometric, by the signal
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 ModeABS00C3M
Specification data are reference values.
On Board Diagnosis LogicABS00C3N
The heated oxygen sensor 2 has a much longer switching time
between rich and lean than the heated oxygen sensor 1. The oxygen
storage capacity of the three way catalyst (manifold) 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.
SEF327R
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 (B1)
HO2S2 (B2)

Warm-up condition

After keeping engine speed
between 3,500 and 4,000 rpm for
1 minute and at idle for 1 minute
under no loadRevving engine from idle to 3,000 rpm
quickly0 - 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 responseIt takes more time for the sensor to respond
between rich and lean than the specified time.

Harness or connectors
(The sensor circuit is open or shorted)

Heated oxygen sensor 2

Fuel pressure

Fuel injector

Intake air leaks P0159
0159
(Bank 2)

EC-914
[VK45DE]
DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
Revision: 2004 November 2004 FX35/FX45
DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTIONPFP:16600
On Board Diagnosis LogicABS00C3U
With the Air-Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensors 1. The
ECM calculates the necessary compensation to correct the offset between the actual and the theoretical
ratios.
In case the amount of the compensation value is extremely large (the actual mixture ratio is too lean.), the
ECM judges the condition as the fuel injection system malfunction and lights up the MIL (2 trip detection logic).
DTC Confirmation ProcedureABS00C3V
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.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON and select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CON-
SULT-II.
4. Clear the self-learning control coefficient by touching “CLEAR”.
5. Select “DATA MONITOR” mode with CONSULT-II.
6. Start engine again and let it idle for at least 10 minutes.
The 1st trip DTC P0171 or P0174 should be detected at this
stage, if a malfunction exists. If so, go to EC-918, "
Diagnostic
Procedure" .
7. If it is difficult to start engine at step 6, the fuel injection system
has a malfunction, too.
8. Crank engine while depressing accelerator pedal. If engine
starts, go to EC-918, "
Diagnostic Procedure" . If engine does not
start, check exhaust and intake air leak visually.
Sensor Input signal to ECM ECM function Actuator
Heated oxygen sensor 1Density of oxygen in exhaust gas
(Mixture ratio feedback signal)Fuel injection
controlFuel injector
DTC No.Trouble diagnosis
nameDTC detecting condition Possible cause
P0171
0171
(Bank 1)
Fuel injection system
too lean

Fuel injection system does not operate properly.

The amount of mixture ratio compensation is too
large. (The mixture ratio is too lean.)

Intake air leaks

Heated oxygen sensor 1

Fuel injector

Exhaust gas leaks

Incorrect fuel pressure

Lack of fuel

Mass air flow sensor

Incorrect PCV hose connection P0174
0174
(Bank 2)
SEF968Y

DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
EC-915
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Revision: 2004 November 2004 FX35/FX45
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Disconnect mass air flow sensor harness connector. Then
restart and run engine for at least 5 seconds at idle speed.
4. Stop engine and reconnect mass air flow sensor harness con-
nector.
5. Select MODE 3 with GST. Make sure DTC P0102 is detected.
6. Select MODE 4 with GST and erase the DTC P0102.
7. Start engine again and let it idle for at least 10 minutes.
8. Select MODE 7 with GST. The 1st trip DTC P0171 or P0174
should be detected at this stage, if a malfunction exists. If so, go
to EC-918, "
Diagnostic Procedure" .
9. If it is difficult to start engine at step 7, the fuel injection system
has a malfunction.
10. Crank engine while depressing accelerator pedal. If engine starts, go to EC-918, "
Diagnostic Procedure" .
If engine does not start, check exhaust and intake air leak visually.
PBIB1502E

EC-918
[VK45DE]
DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
Revision: 2004 November 2004 FX35/FX45
Diagnostic ProcedureABS00C3X
1. CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before three way catalyst (manifold).
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2. CHECK FOR INTAKE AIR LEAK
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.
SEC502D

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
EC-927
[VK45DE]
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Revision: 2004 November 2004 FX35/FX45
Diagnostic ProcedureABS00C41
1. CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before three way catalyst (manifold).
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2. CHECK FOR INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
SEC502D