2008 INFINITI FX35 engine

EC-284
< SERVICE INFORMATION >[VQ35DE]
DTC P0172, P0175 FUEL IN
JECTION SYSTEM FUNCTION
DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
On Board Diagnosis LogicINFOID:0000000001326105
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 corr ect 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:0000000001609264
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-LE ARNING 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, the 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 . 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-289, "
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.
Sensor Input signal to ECM ECM function Actuator
Air fuel ration (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.)  Air fuel ratio (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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DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
EC-285
< SERVICE INFORMATION > [VQ35DE]
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EC
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O9. Check 1st trip DTC.
10. The 1st trip is detected, go to
EC-289, "
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 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-289, "
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-289, "
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.
11. Check 1st trip DTC.
12. The 1st trip is detected, go to EC-289, "
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).
PBIB1565E
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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3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
EC-287
< SERVICE INFORMATION > [VQ35DE]
C
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EC
NP
O
Do not use ECM ground terminals wh
en measuring input/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)
2R/L A/F sensor 1 heater
(bank 1) [Engine is running]

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

Warm-up condition
 Idle speed Approximately 3.1V
35 B/R Approximately 2.6V
56 L Approximately 2.3V
75 R/B Approximately 2.3V
21
22
23 W
G
R Fuel injector No. 5
Fuel injector No. 3
Fuel injector No. 1 [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
SEC984C
SEC985C
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3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
EC-289
< SERVICE INFORMATION > [VQ35DE]
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: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnosis ProcedureINFOID:0000000001326108
1.CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before three way catalyst 1.
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 L A/F sensor 1 heater
(bank 2) [Engine is running]

Warm-up condition
 Idle speed Approximately 5V
40
41
42 LG
B
P Fuel injector No. 6
Fuel injector No. 4
Fuel injector No. 2 [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 Y Approximately 2.3V
76 P Approximately 3.1V
77 BR Approximately 2.3V
PBIB1584E
SEC984C
SEC985C
PBIB1922E
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3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
EC-291
< SERVICE INFORMATION > [VQ35DE]
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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-558
.)
 Fuel pressure regulator (Refer to EC-87, "
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 c onnections in the mass air flow sensor circuit or
ground. Refer to EC-175
.
7.CHECK FUNCTION OF FUEL INJECTOR
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 FUEL INJECTOR, refer to EC-552
.
8.CHECK FUNCTION OF FUEL INJECTOR-I
Without CONSULT-III
1. Stop engine.
2. Disconnect harness connector F50, F251
3. Turn ignition switch ON. 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
PBIB2624E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

EC-292
< SERVICE INFORMATION >[VQ35DE]
DTC P0172, P0175 FUEL IN
JECTION SYSTEM FUNCTION
4. Check voltage between harness connector F50 terminal 5 and
ground.
5. Turn ignition switch OFF.
6. Disconnect ECM harness connector.
7. Check harness continuity between harness connector F50 and ECM as follows.
Refer to Wiring Diagram.
8. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 9.
NG >> Perform trouble diagnosis for FUEL INJECTOR, refer to EC-552
.
9.CHECK FUNCTION OF FUEL INJECTOR-II
Provide battery voltage between harness connector F251 as follows
and then interrupt it. Listen to each fuel injector operating sound.
OK or NG
OK >> GO TO 10.
NG >> Perform trouble diagnosis for FUEL INJECTOR, refer to EC-552
.
10.CHECK FUEL INJECTOR
1. Remove fuel injector assembly. Refer to EM-45
.
Keep fuel hose and all fuel injectors connected to fuel injector gallery.
2. Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
3. Reconnect all harness connectors disconnected.
4. Disconnect all fuel injector harness connectors.
5. Disconnect all ignition coil harness connectors.
6. Prepare pans or saucers under each fuel injectors.
7. Crank engine for about 3 seconds.
Make sure fuel does not drip from fuel injector.Voltage: Battery voltage
Cylinder
Harness connector F50
terminal ECM terminal
1623
2442
3222
4341
5121
6740
Continuity should exist.
PBIB2323E
Cylinder Harness connector F251 terminal
(+) (–)
1
56
24
32
43
51
67
Operating sound should exist.
PBIB2497E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

EC-294
< SERVICE INFORMATION >[VQ35DE]
DTC P0181 FTT SENSOR
DTC P0181 FTT SENSOR
Component DescriptionINFOID:0000000001326109
The fuel tank temperature (FTT)
sensor is used to detect the fuel
temperature inside the fuel tank. The sensor modifies a voltage sig-
nal from the ECM. The modified signal returns to the ECM as the
fuel temperature input. The sensor uses a thermistor which is sensi-
tive to the change in temperature. The electrical resistance of the
thermistor decreases as temperature increases.

*: This data is reference values and is 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 terminals, such as the ground.
On Board Diagnosis LogicINFOID:0000000001326110
DTC Confirmation ProcedureINFOID:0000000001326111
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. Wait at least 10 seconds. If 1st trip DTC is detected, go to EC-296, "
Diagnosis Procedure".
If 1st trip DTC is not det ected, go to following step.
3. Select “DATA MONITOR” mode with CONSULT-III.
4. 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.
5. Cool engine down until “COOLAN TEMP/S” is less than 60 °C (140 °F).
6. Wait at least 10 seconds.
7. Check 1st trip DTC.
PBIB1572E
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
(Fuel tank temperature sensor circuit is
open or shorted)
 Fuel tank temperature sensor
 Unified meter and A/C amp.
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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.
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