2005 INFINITI FX35 ABS

EC-34
[VQ35DE]
ENGINE CONTROL SYSTEM
Revision: 2005 July 2005 FX

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)ABS006KA
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM through CAN communication line.
SYSTEM DESCRIPTION
If the engine speed is above 1,800 rpm under no load (for example, the shift position is neutral and engine
speed is over 1,800 rpm) fuel will be cut off after some time. The exact time when the fuel is cut off varies
based on engine speed.
Fuel cut will be operated until the engine speed reaches 1,500 rpm, then fuel cut will be cancelled.
NOTE:
This function is different from deceleration control listed under EC-31, "
Multiport Fuel Injection (MFI) System" .
Sensor Input Signal to ECM ECM function Actuator
Park/neutral position (PNP) switch Neutral position
Fuel cut con-
trol 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

AIR CONDITIONING CUT CONTROL EC-35
[VQ35DE]
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Revision: 2005 July 2005 FX
AIR CONDITIONING CUT CONTROLPFP:23710
Input/Output Signal ChartABS00E8X
*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 DescriptionABS00E8Y
This system improves engine operation 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*
1Air conditioner ON signal
Air conditioner
cut control Air conditioner relay
Accelerator pedal position sensor Accelerator pedal 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 sensor*
1Vehicle speed

EC-36
[VQ35DE]
AUTOMATIC SPEED CONTROL DEVICE (ASCD)
Revision: 2005 July 2005 FX
AUTOMATIC SPEED CONTROL DEVICE (ASCD)PFP:18930
System DescriptionABS006ZG
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 driver 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 throttle control actuator to regulate engine speed.
Operation status of ASCD is indicated by CRUISE indicator and SET indicator in combination meter. If any
malfunction occurs in ASCD system, it automatically deactivates control.
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 indicator in combination meter illuminates.)
ACCEL OPERATION
If the RESUME/ACCELERATE switch is pressed during cruise control driving, increase the vehicle speed until
the switch is released or vehicle speed reaches 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 the 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.
Sensor Input signal to ECM ECM function Actuator
ASCD brake switch Brake pedal operation
ASCD vehicle speed control Electric throttle control
actuator
Stop lamp switch Brake pedal operation
ASCD steering switch ASCD steering switch operation
Park/Neutral position (PNP)
switch Gear position
Unified meter and A/C amp.* Vehicle speed
TCM* Powertrain revolution

AUTOMATIC SPEED CONTROL DEVICE (ASCD) EC-37
[VQ35DE]
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Revision: 2005 July 2005 FX
RESUME OPERATION
When the RESUME/ACCELERATE switch is pressed after cancel operation other than depressing MAIN
switch is performed, vehicle speed will return to last set speed. To resume vehicle set speed, vehicle condition
must meet following conditions.

Brake pedal is released

Selector lever is in other than P and N positions

Vehicle speed is greater than 40 km/h (25 MPH) and less than 144 km/h (89 MPH)
Component DescriptionABS006ZH
ASCD STEERING SWITCH
Refer to EC-581 .
ASCD BRAKE SWITCH
Refer to EC-597 and EC-688 .
STOP LAMP SWITCH
Refer to EC-597 , EC-614 and EC-688 .
ELECTRIC THROTTLE CONTROL ACTUATOR
Refer to EC-424 , EC-426 , EC-432 and EC-437 .
ASCD INDICATOR
Refer to EC-695 .

EC-38
[VQ35DE]
CAN COMMUNICATION
Revision: 2005 July 2005 FX
CAN COMMUNICATIONPFP:23710
System DescriptionABS00E8Z
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only.
Refer to LAN-30, "
CAN COMMUNICATION" , about CAN communication for detail.

EVAPORATIVE EMISSION SYSTEM EC-39
[VQ35DE]
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Revision: 2005 July 2005 FX
EVAPORATIVE EMISSION SYSTEMPFP:14950
DescriptionABS006Z7
SYSTEM DESCRIPTION
The evaporative emission system is used to reduce hydrocarbons emitted into the atmosphere from the fuel
system. This reduction of hydrocarbons is accomplished by activated charcoals in the EVAP canister.
The fuel vapor in the sealed fuel tank is led into the EVAP canister which contains activated carbon and the
vapor is stored there when the engine is not operating or when refueling to the fuel tank.
The vapor in the EVAP canister is purged by the air through the purge line to the intake manifold when the
engine is operating. EVAP canister purge volume control solenoid valve is controlled by ECM. When the
engine operates, the flow rate of vapor controlled by EVAP canister purge volume control solenoid valve is
proportionally regulated as the air flow increases.
EVAP canister purge volume control solenoid valve also shuts off the vapor purge line during decelerating and
idling.
PBIB1631E

EC-42
[VQ35DE]
EVAPORATIVE EMISSION SYSTEM
Revision: 2005 July 2005 FX
Component InspectionABS006Z8
EVAP CANISTER
Check EVAP canister as follows:
1. Block port B .
2. Blow air into port A and check that it flows freely out of port C .
3. Release blocked port B .
4. Apply vacuum pressure to port B and check that vacuum pres-
sure exists at the ports A and C .
5. Block port A and B .
6. Apply pressure to port C and check that there is no leakage.
FUEL TANK VACUUM RELIEF VALVE (BUILT INTO FUEL FULLER CAP)
1. Wipe clean valve housing.
2. Check valve opening pressure and vacuum.
3. If out of specification, replace fuel filler cap as an assembly.
CAUTION:
Use only a genuine fuel filler cap as a replacement. If an incor-
rect fuel filler cap is used, the MIL may come on.
EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Refer to EC-341 .
FUEL TANK TEMPERATURE SENSOR
Refer to EC-271 .
EVAP CANISTER VENT CONTROL VALVE
Refer to EC-348 .
EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to EC-358 .
PBIB1044E
SEF445Y
Pressure:
15.3 - 20.0 kPa (0.156 - 0.204 kg/cm2 , 2.22
- 2.90 psi)
Va c u u m : − 6.0 to −3.3 kPa ( −0.061 to −0.034 kg/cm
2 ,
− 0.87 to −0.48 psi)
SEF943S

EVAPORATIVE EMISSION SYSTEM EC-43
[VQ35DE]
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Revision: 2005 July 2005 FX
EVAP SERVICE PORT
Positive pressure is delivered to the EVAP system through the EVAP
service port. If fuel vapor leakage in the EVAP system occurs, use a
leak detector to locate the leak.
Removal and InstallationABS006Z9
EVAP CANISTER
Tighten EVAP canister as shown in the figure.
EVAP CANISTER VENT CONTROL VALVE
1. Turn EVAP canister vent control valve counterclockwise.
2. Remove the EVAP canister vent control valve.
Always replace O-ring with a new one.
How to Detect Fuel Vapor LeakageABS006ZA
CAUTION:

Never use compressed air or a high pressure pump.

Do not exceed 4.12 kPa (0.042 kg/cm2 , 0.6 psi) of pressure in EVAP system.
NOTE:

Do not start engine.

Improper installation of EVAP service port adapter to the EVAP service port may cause a leak.
SEF462UA
PBIB1029E
PBIB1030E