Infiniti QX56 (Z62). Manual - part 517

 

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Infiniti QX56 (Z62). Manual - part 517

 

 

EC-46

< SYSTEM DESCRIPTION >

[VK56VD]

SYSTEM

*1: ECM determines the start signal status by the signals of engine speed and battery voltage.

*2: This signal is sent to the ECM via the CAN communication line.

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.

AIR CONDITIONING CUT CONTROL

Sensor

Input signal to ECM

ECM function

Actuator

Crankshaft position sensor
Camshaft position sensor

• Engine speed*

1

• Piston position

EVAP canister 
purge flow control

EVAP canister purge volume 
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

EVAP control system pressure sensor

Pressure in purge line

Combination meter

Vehicle speed*

2

PBIB1631E

SYSTEM

EC-47

< SYSTEM DESCRIPTION >

[VK56VD]

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AIR CONDITIONING CUT CONTROL : System Diagram

INFOID:0000000006217713

AIR CONDITIONING CUT CONTROL : System Description

INFOID:0000000006217714

INPUT/OUTPUT SIGNAL CHART

*1: This signal is sent to the ECM via the CAN communication line.

*2: ECM determines the start signal status by the signals of engine speed and battery voltage.

SYSTEM DESCRIPTION

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.

AUTOMATIC SPEED CONTROL DEVICE (ASCD)

JMBIA1457GB

Sensor

Input signal to ECM

ECM function

Actuator

Crankshaft position sensor
Camshaft position sensor

Engine speed*

2

Air conditioner cut 
control

IPDM E/R

A/C relay

Compressor

Engine coolant temperature sensor

Engine coolant temperature

Accelerator pedal position sensor

Accelerator pedal position

Battery

Battery voltage*

2

Refrigerant pressure sensor

Refrigerant pressure

Power steering pressure sensor

Power steering operation

A/C auto amp.

A/C ON signal*

1

A/C evaporator temperature*

1

Target A/C evaporator temperature*

1

Blower fan ON signal

Combination meter

Vehicle speed*

1

EC-48

< SYSTEM DESCRIPTION >

[VK56VD]

SYSTEM

AUTOMATIC SPEED CONTROL DEVICE (ASCD) : System Diagram

INFOID:0000000006217715

AUTOMATIC SPEED CONTROL DEVICE (ASCD) : System Description

INFOID:0000000006217716

INPUT/OUTPUT SIGNAL CHART

*: This signal is sent to the ECM via the CAN communication line

BASIC ASCD SYSTEM

• Automatic Speed Control Device (ASCD) allows a driver to keep vehicle at predetermined constant speed

without depressing accelerator pedal. Driver can be set the vehicle speed in the set speed range.

• ECM controls throttle angle of electric throttle control actuator to regulate engine speed.
• Operation status of ASCD is indicated in combination meter.
• If any malfunction occurs in the ASCD system, it automatically deactivates the ASCD control.
Refer to 

EC-49, "AUTMATIC SPEED CONTROL DEVICE (ASCD) : Switch Name and Function"

 for ASCD

operating instructions.

CAUTION:

Always drive vehicle in a safe manner according to traffic conditions and obey all traffic laws.

CAN COMMUNICATION

CAN COMMUNICATION : System Description

INFOID:0000000006217718

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-28, "CAN COMMUNICATION SYSTEM : CAN Communication Signal Chart"

, about CAN com-

munication for detail.

JPBIA3272GB

Sensor

Input signal to ECM

ECM function

Actuator

ASCD steering switch

ASCD steering switch operation

ASCD vehicle speed control

• Electric throttle control ac-

tuator 

• Combination meter

ASCD brake switch

Brake pedal operation

Stop lamp switch

TCM

Park/neutral position signal

Output shaft revolution signal*

Combination meter

Vehicle speed signal*

OPERATION

EC-49

< SYSTEM DESCRIPTION >

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OPERATION

AUTMATIC SPEED CONTROL DEVICE (ASCD)

AUTMATIC SPEED CONTROL DEVICE (ASCD) : Switch Name and Function

INFOID:0000000006217719

SWITCHES AND INDICATORS

SET SPEED RANGE

ASCD system can be set the following vehicle speed.

SWITCH OPERATION

CANCEL CONDITION

• When any of following conditions exist, the cruise operation is canceled.
- CANCEL switch is pressed
- ASCD MAIN switch pressed (Set speed is cleared)
- More than two switches at ASCD steering switch are pressed at the same time (Set speed is cleared)
- Brake pedal is depressed
- Selector lever position is changed to N, P or R
- Vehicle speed decreased to 13 km/h (8 MPH) lower than the set speed
- TCS system is operated
• When the ECM detects any of the following conditions, the ECM cancels the cruise operation and informs

the driver by blinking CRUISE indicator lamp.

1.

CRUISE indicator lamp

2.

CANCEL switch

3.

ASCD MAIN switch

4.

SET/COAST switch

5.

RESUME/ACCELERATE switch

A.

On the combination meter

B.

On the steering wheel

JPBIA3226ZZ

Minimum speed (Approx.)

Maximum speed (Approx.)

40 km/h (25 MPH)

143 km/h (88 MPH)

Item

Function

CANCEL switch

Cancels the cruise control driving. 

RESUME/ACCELERATE switch

• Resumes the set speed.
• Increases speed incrementally during cruise control driving.

SET/COAST switch

• Sets desired cruise speed.
• Decreases speed incrementally during cruise control driving.

ASCD MAIN switch

Master switch to activate the ASCD system. 
(CRUISE indicator lamp is turned ON when ASCD system is ON.)

 

 

 

 

 

 

 

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