sensor INFINITI FX35 2008 Service Manual

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
EC-871
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DTC P0172, P0175 FUEL IN
JECTION SYSTEM FUNCTION
On Board Diagnosis LogicINFOID:0000000001326702
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 air fuel ratio (A/F) sensor 1. The
ECM calculates the necessary compensation to corre ct the offset between the actual and the theoretical
ratios.
In case the amount of the compensation value is extrem ely large (The actual mixture ratio is too rich.), the
ECM judges the condition as the fuel injection system malfunction and lights up the MIL (2 trip detection logic).
DTC Confirmation ProcedureINFOID:0000000001326703
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
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-III.
4. Clear the self-learning control coefficient by touching “CLEAR”.
5. Start engine. If it is difficult to start engine, t he fuel injection system has a malfunction.
Perform the following procedure is advised.
a. Crank engine while depressing accelerator pedal.
b. If engine starts, go to EC-866, "
Diagnosis Procedure".
If engine does not start, remove ignition plugs and check for fouling, etc.
6. Keep engine at idle for at least 10 minutes.
7. Check 1st trip DTC.
8. If 1st trip DTC is detected, go to EC-866, "
Diagnosis Procedure".
If 1st trip DTC is not detected, per forming 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 condi tions 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 Da ta means the vehicle operation that the following con-
ditions should be satisfied at the same time.
Sensor Input Signal to ECM ECM function Actuator
A/F 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
P0172
0172
(Bank 1) Fuel injection system too
rich  Fuel injection system does not operate properly.
 The amount of mixture ratio compensation is too
large. (The mixture ratio is too rich.)  A/F sensor 1
 Fuel injector
 Exhaust gas leaks
 Incorrect fuel pressure
 Mass air flow sensor
P0175
0175
(Bank 2)
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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EC-872
< SERVICE INFORMATION >[VK45DE]
DTC P0172, P0175 FUEL IN
JECTION SYSTEM FUNCTION
9. Check 1st trip DTC.
10. The 1st trip is detected, go to EC-866, "
Diagnosis Procedure".
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 (1) 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 Service $03 with GST. Make sure DTC P0102 is detected.
6. Select Service $04 with GST and erase the DTC P0102.
7. Start engine. If it is difficult to start engine, the fuel injection system has a mal-
function.
Perform the following procedure is advised.
a. Crank engine while depressing accelerator pedal.
b. If engine starts, go to EC-866, "
Diagnosis Procedure".
If engine does not start, remove ignition plugs and check for fouling, etc.
8. Keep engine at idle for at least 10 minutes.
9. Check 1st trip DTC.
10. If 1st trip DTC is detected, go to EC-866, "
Diagnosis Procedure".
If 1st trip DTC is not detected, per forming 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 Da ta means the vehicle operation that the following con-
ditions should be satisfied at the same time.
11. Check 1st trip DTC.
12. The 1st trip is detected, go to EC-866, "
Diagnosis Procedure".
Engine coolant temperature (T)
conditionWhen 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).
PBIB3230E
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-874
< SERVICE INFORMATION >[VK45DE]
DTC P0172, P0175 FUEL IN
JECTION SYSTEM FUNCTION
Do not use ECM ground terminals when measuring in put/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground ot her than ECM terminals, such as the ground.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)TER-
MI-
NAL NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
2P A/F sensor 1 heater
(Bank 1) [Engine is running]

Warm-up condition
 Idle speed Approximately 5V
16 R A/F sensor 1 (Bank 1) [Engine is running]

Warm-up condition
 Idle speed Approximately 3.1V
35 G Approximately 2.6V
56 B Approximately 2.3V
75 OR Approximately 2.3V
21
22
23
44 W
R
P
OR Fuel injector No. 5
Fuel injector No. 3
Fuel injector No. 1
Fuel injector No. 7 [Engine is running]

Warm-up condition
 Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idle BATTERY VOLTAGE
(11 - 14V)
[Engine is running]
 Warm-up condition
 Engine speed: 2,000 rpm BATTERY VOLTAGE
(11 - 14V)
PBIB1584E
PBIB0042E
PBIB0043E
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EC-876
< SERVICE INFORMATION >[VK45DE]
DTC P0172, P0175 FUEL IN
JECTION SYSTEM FUNCTION
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnosis ProcedureINFOID:0000000001326705
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
TER- MI-
NAL
NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
24 P A/F sensor 1 heater
(Bank 2) [Engine is running]

Warm-up condition
 Idle speed Approximately 5V
40
41
42
63 PU
BR
B
G Fuel injector No. 6
Fuel injector No. 4
Fuel injector No. 2
Fuel injector No. 8 [Engine is running]

Warm-up condition
 Idle speed NOTE:
The pulse cycle changes depending on rpm
at idle BATTERY VOLTAGE
(11 - 14V)
[Engine is running]
 Warm-up condition
 Engine speed: 2,000 rpm BATTERY VOLTAGE
(11 - 14V)
57 G A/F sensor 1 (Bank 2) [Engine is running]

Warm-up condition
 Idle speed Approximately 2.6V
58 L Approximately 2.3V
76 R Approximately 3.1V
77 OR Approximately 2.3V
PBIB1584E
PBIB0042E
PBIB0043E
PBIB1216E
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DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
EC-877
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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)
SENSOR 1 INPUT SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect air fuel ratio (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 power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
: Vehicle front 1. A/F sensor 1 (Bank 2) harness connector2. A/F sensor 1 (Bank 1)
harness connector
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.
PBIB3246E
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EC-878
< SERVICE INFORMATION >[VK45DE]
DTC P0172, P0175 FUEL IN
JECTION SYSTEM FUNCTION
4.CHECK FUEL PRESSURE
1. Release fuel pressure to zero. Refer to EC-665, "
Fuel Pressure Check".
2. Install fuel pressure gauge and check fuel pressure. Refer to EC-665, "
Fuel Pressure Check".
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the following.
 Fuel pump and circuit (Refer to EC-1155
.)
 Fuel pressure regulator (Refer to EC-665, "
Fuel Pressure Check".)
>> Repair or replace.
6.CHECK MASS AIR FLOW SENSOR
With CONSULT-III
1. Install all removed parts.
2. Check “MASS AIR FLOW” in “DATA MONITOR” mode with CONSULT-III.
With GST
1. Install all removed parts.
2. Check mass air flow sensor signal in “Service $01” with GST.
OK or NG
OK (With CONSULT-III)>>GO TO 7.
OK (Without CONSULT-III)>>GO TO 8.
NG >> Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or
grounds. Refer to EC-768
.
7.CHECK FUNCTION OF FUEL INJECTOR-I
With CONSULT-III
1. Start engine.
2. Perform “POWER BALANCE” in “A CTIVE TEST” mode with CONSULT-III.
3. Make sure that each circuit produces a momentary engine speed drop.
OK or NG
OK >> GO TO 10.
NG >> Perform trouble diagnosis for EC-1149
.
8.CHECK FUNCTION OF FUEL INJECTOR-I
Without CONSULT-III
1. Turn ignition switch OFF.
2. Disconnect harness connectors F21, F 201 (Bank 1) and F41, F221 (Bank 2).
At idling: Approximately 350 kPa (3.57 kg/cm
2, 51 psi)
2.0 - 6.0 g·m/sec: at idling
7.0 - 20.0 g·m/sec: at 2,500 rpm
2.0 - 6.0 g·m/sec: at idling
7.0 - 20.0 g·m/sec: at 2,500 rpm
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DTC P0181 FTT SENSOREC-881
< SERVICE INFORMATION > [VK45DE]
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DTC P0181 FTT SENSOR
Component DescriptionINFOID:0000000001326706
The fuel tank temperature sensor
is used to detect the fuel tempera-
ture inside the fuel tank. The sensor modifies a voltage signal from
the ECM. The modified signal returns to the ECM as the fuel temper-
ature input. The sensor uses a ther mistor which is sensitive to the
change in temperature. The electrical resistance of the thermistor
decreases as temperature increases.

*: These data are reference values and are measured between ECM terminal 107
(Fuel tank 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:0000000001326707
DTC Confirmation ProcedureINFOID:0000000001326708
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
1. Turn ignition switch ON and wait at least 10 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-883, "
Diagnosis Procedure".
If 1st trip DTC is not detected, go to following step.
4. Select “COOLAN TEMP/S” in “DAT A MONITOR” mode with CONSULT-III.
5. Check “COOLAN TEMP/S” value. If “COOLAN TEMP/S” is less than 60 °C (140 °F), the result will be OK.
If “COOLAN TEMP/S” is above 60 °C (140 °F), go to the following step.
6. Cool engine down until “COOLAN TEMP/S” is less than 60 °C (140 °F).
7. Wait at least 10 seconds.
8. Check 1st trip DTC.
PBIB1507E
Fluid temperature °C ( °F) Voltage*
V Resistance
kΩ
20 (68) 3.5 2.3 - 2.7
50 (122) 2.2 0.79 - 0.90
SEF012P
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0181
0181 Fuel tank temperature
sensor circuit range/per-
formance Rationally incorrect voltage from the sensor is
sent to ECM, compared with the voltage signals
from engine coolant temperature sensor and in-
take air temperature sensor.
 Harness or connectors
(The sensor circuit is open or shorted)
 Fuel tank temperature sensor
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EC-882
< SERVICE INFORMATION >[VK45DE]
DTC P0181 FTT SENSOR
9. If 1st trip DTC is detected, go to
EC-883, "Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Wiring DiagramINFOID:0000000001326709
TBWM1334E
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DTC P0181 FTT SENSOREC-883
< SERVICE INFORMATION > [VK45DE]
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Diagnosis ProcedureINFOID:0000000001326710
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-723, "
Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK DTC WITH “UNIFIED METER AND A/C AMP.”
Refer to DI-27, "
CONSULT-III Function (METER/M&A)".
OK or NG
OK >> GO TO 3.
NG >> Go to DI-19, "
Fuel Level Sensor Signal Inspection".
3.CHECK FUEL TANK TEMPERATURE SENSOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect “fuel level sensor unit and fuel pump” harness con- nector.
3. Turn ignition switch ON.
4. Check voltage between “fuel level sensor unit and fuel pump” terminal 4 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4.DETECT MALFUNCTIONING PART
Check the following.
 Harness connectors B1, M11
 Harness for open or short between ECM and “fuel level sensor unit and fuel pump”
PBIB2195E
PBIB1507E
Voltage: Approximately 5V
PBIB0932E
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EC-884
< SERVICE INFORMATION >[VK45DE]
DTC P0181 FTT SENSOR
>> Repair open circuit or short to ground or short to power in harness or connector.
5.CHECK FUEL TANK TEMPERATURE SENSOR
GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect “unified meter and A/C amp.” harness connector.
3. Check harness continuity between “fuel level sensor unit and fuel pump” terminal 5 and “unified meter and
A/C amp.” terminal 36. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6.DETECT MALFUNCTIONING PART
Check the following.
 Harness connectors B1, M11
 Harness for open or short between “fuel level sensor unit and fuel pump” and “unified meter and A/C amp.”
>> Repair open circuit or short to ground or short to power in harness or connector.
7.CHECK FUEL TANK TEMPERATURE SENSOR
Refer to EC-884, "
Component Inspection".
OK or NG
OK >> GO TO 8.
NG >> Replace “fuel level sensor unit and fuel pump”.
8.CHECK INTERMITTENT INCIDENT
Refer to EC-717
.
>> INSPECTION END
Component InspectionINFOID:0000000001326711
FUEL TANK TEMPERATURE SENSOR
1. Remove fuel level sensor unit.
2. Check resistance between “fuel level sensor unit and fuel pump”
terminals 4 and 5 by heating with hot water.
Removal and InstallationINFOID:0000000001326712
FUEL TANK TEMPERATURE SENSOR
Refer to FL-4.
Continuity should exist.
Temperature
°C ( °F) Resistance k Ω
20 (68) 2.3 - 2.7
50 (122) 0.79 - 0.90
PBIB0931E
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