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![INFINITI FX35 2005 Service Manual EC-984
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DTC P0139, P0159 HO2S2
Revision: 2005 July 2005 FX
5. CHECK HEATED OXYGEN SENSOR 2
Refer to EC-984, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Replace malfunctioning INFINITI FX35 2005 Service Manual EC-984
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DTC P0139, P0159 HO2S2
Revision: 2005 July 2005 FX
5. CHECK HEATED OXYGEN SENSOR 2
Refer to EC-984, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Replace malfunctioning](/manual-img/42/57020/w960_57020-2376.png)
EC-984
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DTC P0139, P0159 HO2S2
Revision: 2005 July 2005 FX
5. CHECK HEATED OXYGEN SENSOR 2
Refer to EC-984, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Replace malfunctioning heated oxygen sensor 2.
6. CHECK INTERMITTENT INCIDENT
Refer to EC-854, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component InspectionABS007M1
HEATED OXYGEN SENSOR 2
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 1 minute.
6. Select “FUEL INJECTION” in “ACTIVE TEST” mode, and select “HO2S2 (B1)/(B2)” as the monitor item with CONSULT-II.
7. Check “HO2S2 (B1)/(B2)” at idle speed when adjusting “FUEL INJECTION” to ±25%.
“HO2S2 (B1)/(B2)” should be above 0.62V at least once when the “FUEL INJECTION” is +25%.
“HO2S2 (B1)/(B2)” should be below 0.48V at least once when the “FUEL INJECTION” is −25%.
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.
SEF174Y
SEF662Y
PBIB1624E
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Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread INFINITI FX35 2005 Service Manual DTC P0139, P0159 HO2S2 EC-985
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Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread](/manual-img/42/57020/w960_57020-2377.png)
DTC P0139, P0159 HO2S2 EC-985
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Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread
Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
Without CONSULT-II
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 (B1) signal] or 74 [HO2S2 (B2) 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 above 0.62V at least once during this
procedure.
If the voltage is above 0.62V at step 6, step 7 is not neces-
sary.
7. Keep vehicle at idling for 10 minutes, then check voltage. Or check the voltage when coasting from 80 km/h (50 MPH) in D
position.
The voltage should be below 0.48V at least once during this
procedure.
8. If NG, replace heated oxygen sensor 2.
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 system threads using Oxygen Sensor Thread
Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
Removal and InstallationABS007M2
HEATED OXYGEN SENSOR 2
Refer to EM-182, "EXHAUST MANIFOLD AND THREE WAY CATALYST" .
PBIB2024E
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![INFINITI FX35 2005 Service Manual EC-986
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DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
Revision: 2005 July 2005 FX
DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTIONPFP:16600
On Board Diagnosis LogicABS00E50
With the Air-Fuel INFINITI FX35 2005 Service Manual EC-986
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DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
Revision: 2005 July 2005 FX
DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTIONPFP:16600
On Board Diagnosis LogicABS00E50
With the Air-Fuel](/manual-img/42/57020/w960_57020-2378.png)
EC-986
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DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
Revision: 2005 July 2005 FX
DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTIONPFP:16600
On Board Diagnosis LogicABS00E50
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 ProcedureABS00E51
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-990, "
Diagnostic
Procedure" .
NOTE:
If 1st trip DTC is not detected during above procedure, perform-
ing the following procedure is advised.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Start engine and drive the vehicle under the similar conditions to (1st trip) Freeze Frame Data for 10 minutes. Refer to the table below.
Hold the accelerator pedal as steady as possible.
The similar conditions to (1st trip) Freeze Frame Data means the vehicle operation that the following con-
ditions should be satisfied at the same time.
Sensor Input Signal to ECM ECM function Actuator
Heated oxygen sensor 1 Density of oxygen in exhaust gas
(Mixture ratio feedback signal) Fuel injection control Fuel injector
DTC No. Trouble diagnosis name DTC 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
Engine speed Engine speed in the freeze frame data ± 400 rpm
Vehicle speed Vehicle speed in the freeze frame data ± 10 km/h (6 MPH)
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Revision: 2005 July 2005 FX7. If it is difficult to start engine at step 6, the fuel injection s INFINITI FX35 2005 Service Manual DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION EC-987
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Revision: 2005 July 2005 FX7. If it is difficult to start engine at step 6, the fuel injection s](/manual-img/42/57020/w960_57020-2379.png)
DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION EC-987
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Revision: 2005 July 2005 FX7. 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-990, "
Diagnostic Procedure" .
If engine does not start, check exhaust and intake air leak visually.
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.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness con- nector.
6. Select Service $03 with GST. Make sure DTC P0102 is detected.
7. Select Service $04 with GST and erase the DTC P0102.
8. Start engine again and let it idle for at least 10 minutes.
9. Select Service $07 with GST. The 1st trip DTC P0171 or P0174 should be detected at this stage, if a malfunction exists. If so, go
to EC-990, "
Diagnostic Procedure" .
NOTE:
If 1st trip DTC is not detected during above procedure, performing the following procedure is advised.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Start engine and drive the vehicle under the similar conditions to (1st trip) Freeze Frame Data for 10 min- utes. Refer to the table below.
Hold the accelerator pedal as steady as possible.
The similar conditions to (1st trip) Freeze Frame Data means the vehicle operation that the following con-
ditions should be satisfied at the same time.
10. If it is difficult to start engine at step 8, the fuel injection system has a malfunction.
11. Crank engine while depressing accelerator pedal. If engine starts, go to EC-990, "
Diagnostic Procedure" .
If engine does not start, check exhaust and intake air leak visually.
Engine coolant temperature
(T) condition When the freeze frame data shows lower than 70
°C (158 °F),
T should be lower than 70 °C (158 °F).
When the freeze frame data shows higher than or equal to 70 °C (158 °F),
T should be higher than or equal to 70 °C (158 °F).
PBIB1502E
Engine speed Engine speed in the freeze frame data ± 400 rpm
Vehicle speed Vehicle speed in the freeze frame data ± 10 km/h (6 MPH)
Engine coolant temperature
(T) condition When the freeze frame data shows lower than 70
°C (158 °F),
T should be lower than 70 °C (158 °F).
When the freeze frame data shows higher than or equal to 70 °C (158 °F),
T should be higher than or equal to 70 °C (158 °F).
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EC-988
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DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
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Wiring DiagramABS00E52
BANK 1
TBWM0232E
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DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION EC-989
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BANK 2
TBWM0233E
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EC-990
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DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
Revision: 2005 July 2005 FX
Diagnostic ProcedureABS00E53
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
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3. CHECK HEATED OXYGEN SENSOR 1 CIRCUIT FOR OPEN AND SHORT
1. Turn INFINITI FX35 2005 Service Manual DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION EC-991
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3. CHECK HEATED OXYGEN SENSOR 1 CIRCUIT FOR OPEN AND SHORT
1. Turn](/manual-img/42/57020/w960_57020-2383.png)
DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION EC-991
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3. CHECK HEATED OXYGEN SENSOR 1 CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect corresponding heated oxygen sensor 1 (HO2S1) harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between ECM terminal and HO2S1 terminal as follows. Refer to Wiring Diagram.
5. Check harness continuity between the following terminals and ground. Refer to Wiring Diagram.
6. Check harness continuity between HO2S1 terminal 4 and ECM terminal 78.
7. 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-789, "
FUEL PRESSURE RELEASE" .
2. Install fuel pressure gauge and check fuel pressure. Refer to EC-789, "
FUEL PRESSURE CHECK" .
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
DTC Te r m i n a l s
Bank
ECM Sensor
P0171 16 1 1
P0174 35 1 2
Continuity should exist.
PBIB1521E
DTC Te r m i n a l s
Bank
ECM Sensor
P0171 16 1 1
P0174 35 1 2
Continuity should not exist.
Continuity should exist.
At idling: 350 kPa (3.57 kg/cm2 , 51 psi)