coolant temperature sensor INFINITI FX35 2005 Workshop Manual

DTC P0181 FTT SENSOR EC-267
[VQ35DE]
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Revision: 2005 July 2005 FX
DTC P0181 FTT SENSORPFP:22630
Component DescriptionABS006P6
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 thermistor which is sensitive to the
change in temperature. The electrical resistance of the thermistor
decreases as temperature increases.

*: This data is reference value 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 LogicABS006P7
DTC Confirmation ProcedureABS006P8
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. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Wait at least 10 seconds. If the result is NG, go to EC-270, "
Diagnostic Procedure" .
If the result is OK, go to following step.
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. If 1st trip DTC is detected, go to EC-270, "
Diagnostic Procedure" .
PBIB1572E
Fluid temperature
° C ( °F) Voltage*
V Resistance
k Ω
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/
performance Rationally incorrect voltage from the sensor is
sent to ECM, compared with the voltage sig-
nals from engine coolant temperature sensor
and intake air temperature sensor.

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

Fuel tank temperature sensor

Unified meter and A/C amp.
SEF174Y

EC-336
[VQ35DE]
DTC P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Revision: 2005 July 2005 FX
DTC P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID
VA LV E
PFP:14920
DescriptionABS006QT
SYSTEM DESCRIPTION
*1: ECM determines the start signal status by the signals of engine speed and battery voltage.
*2: This signal is sent to the ECM through CAN communication line.
This system controls flow rate of fuel vapor from the EVAP canister. The opening of the vapor by-pass pas-
sage in the EVAP canister purge volume control solenoid valve changes to control the flow rate. The EVAP
canister purge volume control solenoid valve repeats ON/OFF operation according to the signal sent from the
ECM. The opening of the valve varies for optimum engine control. The optimum value stored in the ECM is
determined by considering various engine conditions. When the engine is operating, the flow rate of fuel vapor
from the EVAP canister is regulated as the air flow changes.
COMPONENT DESCRIPTION
The EVAP canister purge volume control solenoid valve uses a ON/
OFF duty to control the flow rate of fuel vapor from the EVAP canis-
ter. The EVAP canister purge volume control solenoid valve is
moved by ON/OFF pulses from the ECM. The longer the ON pulse,
the greater the amount of fuel vapor that will flow through the valve.
CONSULT-II Reference Value in Data Monitor ModeABS006QU
Specification data are reference values.
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE) Engine speed*
1
EVAP canister
purge flow control EVAP canister purge vol-
ume control solenoid valve
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Battery Battery voltage*
1
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Air fuel ratio (A/F) sensor 1 Density of oxygen in exhaust gas
(Mixture ratio feedback signal)
Fuel tank temperature sensor Fuel temperature in fuel tank
Wheel sensor*
2Vehicle speed
SEF337U
MONITOR ITEM CONDITION SPECIFICATION
PURG VOL C/V

Engine: After warming up

Selector lever: P or N

Air conditioner switch: OFF

No-load Idle
(Accelerator pedal is not depressed
even slightly, after engine starting) 0%
2,000 rpm —

DTC P1217 ENGINE OVER TEMPERATURE EC-467
[VQ35DE]
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Revision: 2005 July 2005 FX
DTC P1217 ENGINE OVER TEMPERATUREPFP:00000
DescriptionABS00B4M
SYSTEM DESCRIPTION
NOTE:
If DTC P1217 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC U1000,
U1001. Refer to EC-171
.
Cooling Fan Control
*1: The ECM determines the start signal status by the signals of engine speed and battery voltage.
*2: This signal is sent to ECM through CAN communication line.
The ECM controls the cooling fan corresponding to the vehicle speed, engine coolant temperature, refrigerant
pressure, and air conditioner ON signal. The control system has 4-step control [HIGH/MIDDLE/LOW/OFF].
Cooling Fan Operation
Sensor Input Signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE) Engine speed*
1
Cooling fan
control IPDM E/R
(Cooling fan relay)
Battery
Battery voltage*
1
Wheel sensor*2Vehicle speed
Engine coolant temperature sensor Engine coolant temperature
Air conditioner switch*
2Air conditioner ON signal
Refrigerant pressure sensor Refrigerant pressure
PBIB2215E

EC-474
[VQ35DE]
DTC P1217 ENGINE OVER TEMPERATURE
Revision: 2005 July 2005 FX
5. CHECK RADIATOR CAP
Apply pressure to cap with a tester.
OK or NG
OK >> GO TO 6.
NG >> Replace radiator cap.
6. CHECK THERMOSTAT
1. Check valve seating condition at normal room temperatures. It should seat tightly.
2. Check valve opening temperature and valve lift.
3. Check if valve is closed at 5 °C (9 °F) below valve opening tem-
perature.
For details, refer to CO-26, "
WATER INLET AND THERMO-
STAT ASSEMBLY" .
OK or NG
OK >> GO TO 7.
NG >> Replace thermostat
7. CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-212, "
Component Inspection" .
OK or NG
OK >> GO TO 8.
NG >> Replace engine coolant temperature sensor.
8. CHECK MAIN 12 CAUSES
If the cause cannot be isolated, go to EC-478, "
Main 12 Causes of Overheating" .
>> INSPECTION END
Radiator cap relief pressure:
59 - 98 kPa (0.6 - 1.0 kg/cm
2
, 9 - 14 psi)
SLC755A
Valve opening temperature: 76.5 °C (170 °F) [standard]
Valve lift: More than 8.6 mm/90 °C
(0.339 in/194 °F)
SLC343

EC-560
[VQ35DE]
DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Revision: 2005 July 2005 FX
DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
PFP:14920
DescriptionABS006VU
SYSTEM DESCRIPTION
*1: ECM determines the start signal status by the signals of engine speed and battery voltage.
*2: This signal is sent to the ECM through CAN communication line.
This system controls flow rate of fuel vapor from the EVAP canister. The opening of the vapor by-pass pas-
sage in the EVAP canister purge volume control solenoid valve changes to control the flow rate. The EVAP
canister purge volume control solenoid valve repeats ON/OFF operation according to the signal sent from the
ECM. The opening of the valve varies for optimum engine control. The optimum value stored in the ECM is
determined by considering various engine conditions. When the engine is operating, the flow rate of fuel vapor
from the EVAP canister is regulated as the air flow changes.
COMPONENT DESCRIPTION
The EVAP canister purge volume control solenoid valve uses a ON/
OFF duty to control the flow rate of fuel vapor from the EVAP canis-
ter. The EVAP canister purge volume control solenoid valve is
moved by ON/OFF pulses from the ECM. The longer the ON pulse,
the greater the amount of fuel vapor that will flow through the valve.
CONSULT-II Reference Value in Data Monitor ModeABS006VV
Specification data are reference values.
Sensor Input Signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE) Engine speed*
1
EVAP canister
purge flow control EVAP canister purge vol-
ume control solenoid valve
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Battery Battery voltage*
1
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Air fuel ratio (A/F) sensor 1 Density of oxygen in exhaust gas
(Mixture ratio feedback signal)
Fuel tank temperature sensor Fuel temperature in fuel tank
Wheel sensor*
2Vehicle speed
SEF337U
MONITOR ITEM CONDITION SPECIFICATION
PURG VOL C/V

Engine: After warming up

Selector lever: P or N

Air conditioner switch: OFF

No-load Idle
(Accelerator pedal is not depressed
even slightly, after engine starting) 0%
2,000 rpm —

SERVICE DATA AND SPECIFICATIONS (SDS) EC-705
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Revision: 2005 July 2005 FX
SERVICE DATA AND SPECIFICATIONS (SDS)PFP:00030
Fuel PressureABS006ZI
Idle Speed and Ignition TimingABS006ZJ
*1: Under the following conditions:

Air conditioner switch: OFF

Electric load: OFF (Lights, heater fan & rear window defogger)

Steering wheel: Kept in straight-ahead position
Calculated Load ValueABS006ZK
Mass Air Flow SensorABS006ZL
*: Engine is warmed up to normal operating temperature and running under no-load.
Intake Air Temperature SensorABS006ZM
Engine Coolant Temperature SensorABS006ZN
Air Fuel Ratio (A/F) Sensor 1 HeaterABS006ZO
Heated Oxygen sensor 2 HeaterABS006ZP
Crankshaft Position Sensor (POS)ABS006ZQ
Refer to EC-306, "Component Inspection" .
Camshaft Position Sensor (PHASE)ABS006ZR
Refer to EC-315, "Component Inspection" .
Throttle Control MotorABS006ZS
Fuel pressure at idling kPa (kg/cm2 , psi) Approximately 350 (3.57, 51)
Target idle speed
No-load*1 (in P or N position) 650
±50 rpm
Air conditioner: ON In P or N position 700 rpm or more
Ignition timing In P or N position 15 ° ± 5 ° BTDC
Calculated load value% (Using CONSULT-II or GST)
At idle 5 - 35
At 2,500 rpm 5 - 35
Supply voltageBattery voltage (11 - 14V)
Output voltage at idle 1.0 - 1.2*V
Mass air flow (Using CONSULT-II or GST) 2.0 - 6.0 g·m/sec at idle*
7.0 - 20.0 g·m/sec at 2,500 rpm*
Temperature °C ( °F) Resistance k Ω
25 (77) 1.94 - 2.06
80 (176) 0.295 - 0.349
Temperature °C ( °F) Resistance k Ω
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
Resistance [at 25°C (77 °F)] 2.3 - 4.3 Ω
Resistance [at 25°C (77 °F)] 5.0 - 7.0 Ω
Resistance [at 25°C (77 °F)] Approximately 1 - 15 Ω

EC-720
[VK45DE]
PREPARATION
Revision: 2005 July 2005 FX
Commercial Service ToolsABS007HD
Tool name
(Kent-Moore No.) Description
Leak detector
i.e.: (J-41416) Locating the EVAP leak
EVAP service port
adapter
i.e.: (J-41413-OBD) Applying positive pressure through EVAP service
port
Fuel filler cap adapter
i.e.: (MLR-8382) Checking fuel tank vacuum relief valve opening
pressure
Socket wrench Removing and installing engine coolant temperature sensor
Oxygen sensor thread
cleaner
i.e.: (J-43897-18)
(J-43897-12) Reconditioning the exhaust system threads
before installing a new oxygen sensor. Use with
anti-seize lubricant shown below.
a: 18 mm diameter with pitch 1.5 mm for
Zirconia Oxygen Sensor
b: 12 mm diameter with pitch 1.25 mm for
Titania Oxygen Sensor
Anti-seize lubricant
i.e.: (Permatex
TM
133AR or equivalent
meeting MIL
specification MIL-A-
907) Lubricating oxygen sensor thread cleaning tool
when reconditioning exhaust system threads.
S-NT703
S-NT704
S-NT815
S-NT705
AEM488
S-NT779

EC-722
[VK45DE]
ENGINE CONTROL SYSTEM
Revision: 2005 July 2005 FX
Multiport Fuel Injection (MFI) SystemABS00E3Y
INPUT/OUTPUT SIGNAL CHART
*1: This sensor is not used to control the engine system under normal conditions.
*2: This signal is sent to the ECM through CAN communication line.
*3: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
The amount of fuel injected from the fuel injector is determined by the ECM. The ECM controls the length of
time the valve remains open (injection pulse duration). The amount of fuel injected is a program value in the
ECM memory. The program value is preset by engine operating conditions. These conditions are determined
by input signals (for engine speed and intake air) from the crankshaft position sensor (POS), camshaft position
sensor (PHASE) and the mass air flow sensor.
VARIOUS FUEL INJECTION INCREASE/DECREASE COMPENSATION
In addition, the amount of fuel injected is compensated to improve engine performance under various operat-
ing conditions as listed below.


During warm-up

When starting the engine

During acceleration

Hot-engine operation

When selector lever is changed from N to D

High-load, high-speed operation


During deceleration

During high engine speed operation
Sensor Input Signal to ECM ECM function Actuator
Crankshaft position sensor (POS) Engine speed*
3
Piston position
Fuel injection
& mixture ratio
control Fuel injector
Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Heated oxygen sensor 1 Density of oxygen in exhaust gas
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Park/neutral position (PNP) switch Gear position
Battery Battery voltage*
3
Knock sensor Engine knocking condition
Power steering pressure sensor Power steering operation
Heated oxygen sensor 2*
1Density of oxygen in exhaust gas
ABS actuator and electric unit (control unit)*
2VDC/TCS operation command
Air conditioner switch*
2Air conditioner operation
Wheel sensor*
2Vehicle speed

ENGINE CONTROL SYSTEM EC-723
[VK45DE]
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MIXTURE RATIO FEEDBACK CONTROL (CLOSED LOOP CONTROL)
The mixture ratio feedback system provides the best air-fuel mixture ratio for driveability and emission control.
The three way catalyst (manifold) can then better reduce CO, HC and NOx emissions. This system uses
heated oxygen sensor 1 in the exhaust manifold to monitor whether the engine operation is rich or lean. The
ECM adjusts the injection pulse width according to the sensor voltage signal. For more information about
heated oxygen sensor 1, refer to EC-935
. This maintains the mixture ratio within the range of stoichiometric
(ideal air-fuel mixture).
This stage is referred to as the closed loop control condition.
Heated oxygen sensor 2 is located downstream of the three way catalyst (manifold). Even if the switching
characteristics of heated oxygen sensor 1 shift, the air-fuel ratio is controlled to stoichiometric by the signal
from heated oxygen sensor 2.
Open Loop Control
The open loop system condition refers to when the ECM detects any of the following conditions. Feedback
control stops in order to maintain stabilized fuel combustion.

Deceleration and acceleration

High-load, high-speed operation

Malfunction of heated oxygen sensor 1 or its circuit

Insufficient activation of heated oxygen sensor 1 at low engine coolant temperature

High engine coolant temperature

During warm-up

After shifting from N to D

When starting the engine
MIXTURE RATIO SELF-LEARNING CONTROL
The mixture ratio feedback control system monitors the mixture ratio signal transmitted from heated oxygen
sensor 1. This feedback signal is then sent to the ECM. The ECM controls the basic mixture ratio as close to
the theoretical mixture ratio as possible. However, the basic mixture ratio is not necessarily controlled as orig-
inally designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) and characteristic
changes during operation (i.e., injector clogging) directly affect mixture ratio.
Accordingly, the difference between the basic and theoretical mixture ratios is monitored in this system. This is
then computed in terms of “injection pulse duration” to automatically compensate for the difference between
the two ratios.
“Fuel trim” refers to the feedback compensation value compared against the basic injection duration. Fuel trim
includes short term fuel trim and long term fuel trim.
“Short term fuel trim” is the short-term fuel compensation used to maintain the mixture ratio at its theoretical
value. The signal from heated oxygen sensor 1 indicates whether the mixture ratio is RICH or LEAN compared
to the theoretical value. The signal then triggers a reduction in fuel volume if the mixture ratio is rich, and an
increase in fuel volume if it is lean.
“Long term fuel trim” is overall fuel compensation carried out long-term to compensate for continual deviation
of the short term fuel trim from the central value. Such deviation will occur due to individual engine differences,
wear over time and changes in the usage environment.
PBIB0121E

EC-724
[VK45DE]
ENGINE CONTROL SYSTEM
Revision: 2005 July 2005 FX
FUEL INJECTION TIMING
Two types of systems are used.
Sequential Multiport Fuel Injection System
Fuel is injected into each cylinder during each engine cycle according to the firing order. This system is used
when the engine is running.
Simultaneous Multiport Fuel Injection System
Fuel is injected simultaneously into all eight cylinders twice each engine cycle. In other words, pulse signals of
the same width are simultaneously transmitted from the ECM.
The eight injectors will then receive the signals two times for each engine cycle.
This system is used when the engine is being started and/or if the fail-safe system (CPU) is operating.
FUEL SHUT-OFF
Fuel to each cylinder is cut off during deceleration, operation of the engine at excessively high speeds or oper-
ation of the vehicle at excessively high speeds.
Electronic Ignition (EI) SystemABS00E3Z
INPUT/OUTPUT SIGNAL CHART
*1: This signal is sent to the ECM through CAN communication line.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
Firing order: 1 - 8 - 7 - 3 - 6 - 5 - 4 - 2
The ignition timing is controlled by the ECM to maintain the best air-fuel ratio for every running condition of the
engine. The ignition timing data is stored in the ECM.
The ECM receives information such as the injection pulse width and camshaft position sensor (PHASE) sig-
nal. Computing this information, ignition signals are transmitted to the power transistor.
During the following conditions, the ignition timing is revised by the ECM according to the other data stored in
the ECM.

At starting

During warm-up

At idle

At low battery voltage
PBIB0122E
Sensor Input Signal to ECM ECM function Actuator
Crankshaft position sensor (POS) Engine speed*
2
Piston position
Ignition timing
control Power transistor
Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Battery Battery voltage*
2
Knock sensor Engine knocking
Park/neutral position (PNP) switch Gear position
Wheel sensor*
1Vehicle speed