2008 INFINITI FX35 Coolant Temperature Sensor

DI-26
< SERVICE INFORMATION >
UNIFIED METER AND A/C AMP
UNIFIED METER AND A/C AMP
System DescriptionINFOID:0000000001328456
 For the unified meter and A/C amp., the signal required for controlling the combination meter are integrated
in the A/C auto amp.
 The unified meter and A/C amp. corresponds to a CONS ULT-III function (self-diagnosis results, CAN diag-
nosis support monitor, data monitor).
COMBINATION METER CONTROL FUNCTION
 Unified meter and A/C amp. receives necessary information for combination meter from each unit by CAN communication.
 Unified meter and A/C amp. transmits a signals with communication line (TX, RX) between unified meter and A/C amp. and combination meter.
Input/output signals between unified meter and A/C amp. and combination meter.
NOTE:
Combination meter performs fail-safe operation when unified meter and A/C amp. communication is malfunctioning. Refer to DI-5, "
Sys-
tem Description".
A/C AUTO AMP. FUNCTION
Unified meter and A/C amp. controls each operation for A/C auto amp. Regarding A/C control, refer to AT C -
24, "Description of Air Conditioner LAN Control System" in ATC section.
OTHER FUNCTIONS
Drive Computer Function
The signals required for the distance to empty (DTE) display are centralized in the unified meter and A/C
amp., converted into data, and transmitted to the disp lay unit (without NAVI) and display control unit (with
NAVI) using CAN communication.
Signal Buffer Function
Unified meter and A/C amp. transmits each signal to other units with CAN communication.
Unit Input Output
Unified meter and A/C amp.  Seat belt buckle switch signal (Driver's side)
 Parking brake signal
 Illumination control nighttime required signal
 Refuel status signal
 Low-fuel warning lamp condition signal
 Combination meter receive error signal
 Delivery destination data signal
 Combination meter specifications signal  Vehicle speed signal (8-pulse)
 Engine speed signal
 Engine coolant temperature signal
 Fuel level sensor signal (resistance value)
 Malfunction indicator lamp signal
 ABS warning lamp signal
 Low tire pressure warning lamp signal
 Run-flat tire wa
rning lamp signal
 Brake warning lamp signal
 A/T CHECK warning lamp signal
 ICC warning lamp signal
 Oil pressure switch signal
 Door switch signal
 AWD warning lamp signal
 Key warning lamp signal
 VDC OFF indicator lamp signal
 SLIP indicator lamp signal
 CRUISE indicator lamp signal
 SET indicator lamp signal
 High beam request signal
 Turn indicator signal
 Snow mode switch signal
 ICC system display signal
 Shift position indicator signal
 Manual mode indicator signal
 Manual mode gear position signal
 CAN communication condition signal of A/T
 Position lights request signal
 Buzzer output signal
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EC-8
Component Inspection ...........................................545
ASCD INDICATOR ..........................................547
Component Description ....................................... ..547
CONSULT-III Reference Value in Data Monitor
Mode .................................................................... ..
547
Wiring Diagram ......................................................548
Diagnosis Procedure .............................................548
ELECTRICAL LOAD SIGNAL .........................550
Description ........................................................... ..550
CONSULT-III Reference Value in Data Monitor
Mode .................................................................... ..
550
Diagnosis Procedure .............................................550
FUEL INJECTOR .............................................552
Component Description ....................................... ..552
CONSULT-III Reference Value in Data Monitor
Mode .................................................................... ..
552
Wiring Diagram ......................................................553
Diagnosis Procedure .............................................554
Component Inspection ...........................................557
Removal and Installation .......................................557
FUEL PUMP .....................................................558
Description ........................................................... ..558
CONSULT-III Reference Value in Data Monitor
Mode .................................................................... ..
558
Wiring Diagram ......................................................559
Diagnosis Procedure .............................................560
Component Inspection ...........................................562
Removal and Installation .......................................562
ICC BRAKE SWITCH ......................................563
Component Description ....................................... ..563
CONSULT-III Reference Value in Data Monitor
Mode .................................................................... ..
563
Wiring Diagram ......................................................564
Diagnosis Procedure .............................................565
Component Inspection ...........................................567
IGNITION SIGNAL ...........................................569
Component Description ....................................... ..569
Wiring Diagram ......................................................570
Diagnosis Procedure .............................................575
Component Inspection ...........................................578
Removal and Installation .......................................580
REFRIGERANT PRESSURE SENSOR ..........581
Component Description ....................................... ..581
Wiring Diagram ......................................................582
Diagnosis Procedure .............................................583
Removal and Installation .......................................585
SNOW MODE SWITCH ...................................586
Description ........................................................... ..586
CONSULT-III Reference Value in Data Monitor
Mode .................................................................... ..
586
Wiring Diagram ......................................................587
Diagnosis Procedure .............................................587
Component Inspection ...........................................589
MIL AND DATA LINK CONNECTOR ...............591
Wiring Diagram .................................................... .591
SERVICE DATA AND SPECIFICATIONS
(SDS) ................................................................
593
Fuel Pressure ....................................................... .593
Idle Speed and Ignition Timing .............................593
Calculated Load Value ..........................................593
Mass Air Flow Sensor ...........................................593
Intake Air Temperature Sensor .............................593
Engine Coolant Temperature Sensor ...................593
Air Fuel Ratio (A/F) Sensor 1 Heater ....................593
Heated Oxygen sensor 2 Heater ..........................593
Crankshaft Position Sensor (POS) .......................594
Camshaft Position Sensor (PHASE) .....................594
Throttle Control Motor .......................................... .594
Fuel Injector ..........................................................594
Fuel Pump .............................................................594
VK45DE
SERVICE INFORMATION .. .......................
595
INDEX FOR DTC ............................................ ..595
DTC No. Index ..................................................... .595
Alphabetical Index .................................................598
PRECAUTIONS .............................................. ..603
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" .............................................................. .
603
Precaution for Procedure without Cowl Top Cover .603
On Board Diagnosis (OBD) System of Engine and
A/T ........................................................................
603
Precaution .............................................................604
PREPARATION ................................................607
Special Service Tool ............................................ .607
Commercial Service Tool ......................................608
ENGINE CONTROL SYSTEM ..........................609
Schematic ............................................................ .609
Multiport Fuel Injection (MFI) System ...................609
Electronic Ignition (EI) System ..............................612
Fuel Cut Control (at No Load and High Engine
Speed) ..................................................................
612
AIR CONDITIONING CUT CONTROL .............614
Input/Output Signal Chart .................................... .614
System Description ...............................................614
AUTOMATIC SPEED CONTROL DEVICE
(ASCD) ..............................................................
615
System Description .............................................. .615
Component Description ........................................616
CAN COMMUNICATION ..................................617
System Description .............................................. .617
EVAPORATIVE EMISSION SYSTEM ..............618
Description ........................................................... .618
Component Inspection ..........................................620
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EC-16
Description ...........................................................1182
CONSULT-III Reference Value in Data Monitor
Mode ....................................................................
1182
Wiring Diagram ....................................................1183
Diagnosis Procedure ...........................................1183
Component Inspection .........................................1185
VARIABLE INDUCTION AIR CONTROL SYS-
TEM (VIAS) .....................................................
1187
Description ...........................................................1187
CONSULT-III Reference Va lue in Data Monitor
Mode ....................................................................
1188
Wiring Diagram ....................................................1189
Diagnosis Procedure ...........................................1190
Component Inspection .........................................1193
Removal and Installation .....................................1193
MIL AND DATA LINK CONNECTOR .............1194
Wiring Diagram ....................................................1194
SERVICE DATA AND SPECIFICATIONS
(SDS) ..............................................................
1196
Fuel Pressure .......................................................1196
Idle Speed and Ignition Timing ............................1196
Calculated Load Value .........................................1196
Mass Air Flow Sensor ..........................................1196
Intake Air Temperature Sensor ............................1196
Engine Coolant Temperature Sensor ..................1196
Fuel Tank Temperature Sensor ...........................1196
Crankshaft Position Sensor (POS) ......................1197
Camshaft Position Sensor (PHASE) ....................1197
A/F Sensor 1 Heater ............................................1197
Heated Oxygen sensor 2 Heater .........................1197
Throttle Control Motor ..........................................1197
Fuel Injector .........................................................1197
Fuel Pump ............................................................1197
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EC-32
< SERVICE INFORMATION >[VQ35DE]
ENGINE CONTROL SYSTEM
*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). T he amount of fuel injected is a program value in the
ECM memory. The program value is preset by engi ne operating conditions. These conditions are determined
by input signals (for engine speed and intake air) from both the crankshaft position sensor and the mass air
flow sensor.
VARIOUS FUEL INJECTION I NCREASE/DECREASE COMPENSATION
In addition, the amount of fuel injected is compens ated 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
MIXTURE RATIO FEEDBACK CONTROL (CLOSED LOOP CONTROL)
The mixture ratio feedback system prov ides the best air-fuel mixture ratio for driveability and emission control.
The three way catalyst 1 can then better reduce CO, HC and NOx emissions. This system uses air fuel ratio
Sensor Input Signal to ECM ECM function Actuator
Crankshaft position sensor (POS) Engine speed*
3
Piston position
Fuel injection
& mixture ratio
controlFuel injector
Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Air fuel ratio (A/F) 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
Knock sensor Engine knocking condition
Battery
Battery voltage*
3
Power steering pressure sensor Power steering operation
Heated oxygen sensor 2*
1Density of oxygen in exhaust gas
Air conditioner switch Air conditioner operation*
2
Wheel sensorVehicle speed*2
PBIB3020E
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ENGINE CONTROL SYSTEMEC-33
< SERVICE INFORMATION > [VQ35DE]
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(A/F) 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 air fuel
ratio (A/F) sensor 1, refer to EC-220
. 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 thr ee way catalyst 1. Even if the switching characteris-
tics of air fuel ratio (A/F) 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 air fuel ratio (A/F) sensor 1 or its circuit
 Insufficient activation of air fuel ratio (A /F) 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 air fuel ratio (A/F)
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 bas ic 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., fuel 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 co mpared 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 compensati on used to maintain the mixture ratio at its theoretical
value. The signal from air fuel ratio (A/F) sensor 1 i ndicates whether the mixture ratio is RICH or LEAN com-
pared to the theoretical value. The signal then triggers a r eduction 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 ca rried 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.
FUEL INJECTION TIMING
Two types of systems are used.
Sequential Multiport Fuel Injection System
Fuel is injected into each cylinder during each engine cycl e 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 six cylinders twice each engine cycle. In other words, pulse signals of
the same width are simultaneously transmitted from the ECM.
The six fuel 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.
SEF179U
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EC-34
< SERVICE INFORMATION >[VQ35DE]
ENGINE CONTROL SYSTEM
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) SystemINFOID:0000000001325897
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 - 2 - 3 - 4 - 5 - 6
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 si gnals are transmitted to the power transistor.
During the following conditions, the ignition timing is re vised by the ECM according to the other data stored in
the ECM.
 At starting
 During warm-up
 At idle
 At low battery voltage
 During acceleration
The knock sensor retard system is designed only for emergencies. The basic ignition timing is programmed
within the anti-knocking zone, if recommended fuel is used under dry conditions. The retard system does not
operate under normal driving conditions. If engine knocking occurs, the knock sensor monitors the condition.
The signal is transmitted to the ECM. The ECM retards the ignition timing to eliminate the knocking condition.
Fuel Cut Control (at No Load and High Engine Speed)INFOID:0000000001325898
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM through CAN communication line.
SYSTEM DESCRIPTION
Sensor Input Signal to ECM ECM function Actuator
Crankshaft position sensor (POS) Engine speed*
2
Piston position
Ignition timing
controlPower 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
Knock sensor Engine knocking
Park/neutral position (PNP) switch Gear position
Battery
Battery voltage*
2
Wheel sensor
Vehicle speed*1
Sensor Input Signal to ECM ECM function Actuator
Park/neutral position (P NP) switch Neutral position
Fuel cut control Fuel injector
Accelerator pedal position sensor Accelerator pedal position
Engine coolant temperature sensor Engine coolant temperature
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)
Engine speed
Wheel sensor Vehicle speed*
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EC-36
< SERVICE INFORMATION >[VQ35DE]
AIR CONDITIONING CUT CONTROL
AIR CONDITIONING CUT CONTROL
Input/Output Signal ChartINFOID:0000000001325899
*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 DescriptionINFOID:0000000001325900
This system improves engine operati
on when the air conditioner is used.
Under the following conditions, the air conditioner is turned OFF.
 When the accelerator pedal is fully depressed.
 When cranking the engine.
 At high engine speeds.
 When the engine coolant temperature becomes excessively high.
 When operating power steering during low engine speed or low vehicle speed.
 When engine speed is excessively low.
 When refrigerant pressure is excessively low or high.
Sensor Input Signal to ECM ECM function Actuator
Air conditioner switch Air conditioner ON signal*
1
Air conditioner
cut controlAir conditio
ner relay
Accelerator pedal position sensor Accelerator pedal position
Throttle position sensor Throttle position
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)
Engine speed*2
Engine coolant temperature sensor Engine coolant temperature
Battery
Battery voltage*
2
Refrigerant pressure sensor Refrigerant pressure
Power steering pressure sensor Power steering operation
Wheel sensorVehicle speed*
1
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AUTOMATIC SPEED CONTROL DEVICE (ASCD)EC-37
< SERVICE INFORMATION > [VQ35DE]
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AUTOMATIC SPEED CONTROL DEVICE (ASCD)
System DescriptionINFOID:0000000001325901
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM through CAN communication line.
BASIC ASCD SYSTEM
Refer to Owner's Manual for ASCD operating instructions.
Automatic Speed Control Device (ASCD) allows a dr
iver to keep vehicle at predetermined constant speed
without depressing accelerator pedal. Driver can set vehicle speed in advance between approximately 40 km/
h (25 MPH) and 144 km/h (89 MPH).
ECM controls throttle angle of electric thro ttle control actuator to regulate engine speed.
Operation status of ASCD is indicated by CRUISE i ndicator and SET indicator in combination meter. If any
malfunction occurs in ASCD system, it automatically deactivates control.
NOTE:
Always drive vehicle in safe manner according to traffic conditions and obey all traffic laws.
SET OPERATION
Press MAIN switch. (The CRUISE indicator in combination meter illuminates.)
When vehicle speed reaches a desired speed between approximately 40 km/h (25 MPH) and 144 km/h (89
MPH), press SET/COAST switch. (Then SET indi cator in combination meter illuminates.)
ACCELERATOR OPERATION
If the RESUME/ACCELERATE switch is pressed during cruise control driving, increase the vehicle speed until
the switch is released or vehicle speed reac hes maximum speed controlled by the system.
And then ASCD will keep the new set speed.
CANCEL OPERATION
When any of following conditions exist, cruise operation will be canceled.
 CANCEL switch is pressed
 More than 2 switches at ASCD steering switch are pressed at the same time (Set speed will be cleared)
 Brake pedal is depressed
 Selector lever is changed to N, P, R position
 Vehicle speed decreased to 13 km/h (8 MPH) lower than the set speed
 VDC/TCS system is operated
When the ECM detects any of the following conditions, the ECM will cancel the cruise operation and inform
the driver by blinking indicator lamp.
 Engine coolant temperature is slightly higher than the normal operating temperature, CRUISE lamp may
blink slowly.
When the engine coolant temperature decreases to t he normal operating temperature, CRUISE lamp will
stop blinking and the cruise operation will be able to work by depressing SET/COAST switch or RESUME/
ACCELERATE switch.
 Malfunction for some self-diagnoses regarding ASCD control: SET lamp will blink quickly.
If MAIN switch is turned to OFF during ASCD is activated, all of ASCD operations will be canceled and vehicle
speed memory will be erased.
COAST OPERATION
When the SET/COAST switch is pressed during cruise control driving, decrease vehicle set speed until the
switch is released. And then ASCD will keep the new set speed.
RESUME OPERATION
Sensor Input signal to ECM ECM function Actuator
ASCD brake switch Brake pedal operation
ASCD vehicle speed controlElectric throttle control
actuator
Stop lamp switch Brake pedal operation
ASCD steering switch ASCD steering switch operation
Park/neutral position (PNP) switch Gear position
Wheel sensor. Vehicle speed*
TCM Powertrain revolution*
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