Nissan Qashqai J11. Manual - part 468

SYSTEM

EC9-27

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- Power window
- Alternator output current
• Automatic transmission
- Automatic transmission idle speed set point function (according to coolant temperature)
- Automatic transmission idle speed increase request
• Mechanical consumers
- Air conditioning
- Power steering
• Diagnosis and protection
- Diagnosis
- Engine protection by oil temperature survey
- CONSULT function
- Manifold absolute pressure sensor signal
The final engine idle speed set point is computed from each comsumer

′

s engine idle speed set point:

• The final corrective torque of the Idle Speed Regulation is obtained taking into account proportional, integral,

and derivative corrections.

ENGINE SPEED LIMITATION

ECM calculates the maximum engine speed set point and controls the maximum engine speed in order to fol-
low the set point.
• Fail-safe mode
• Maximum available engine speed

ENGINE STATE

ECM calculates the engine state from detected engine speed:
• Engine running
- Driving state
- Idling state
• Engine stalled
- Initial state
- Stalled state

POWERTRAIN COORDINATION CONTROL

POWERTRAIN COORDINATION CONTROL : System Description

INFOID:0000000010437573

SYSTEM DESCRIPTION

The powertrain coordination can be explained by following:
• Powertrain coordination inputs
• Preventive anti-jerk
• Gear shift indicator (for details, refer to 

EC9-38, "GEAR SHIFT INDICATOR SYSTEM : System Descrip-

tion"

.)

POWERTRAIN COORDINATION INPUTS

ECM detects following signals necessary to decide the torque set point:
• Gear position
• Torque request from automatic transmission
• Torque request from ABS system
• Brake pedal operation
• Status of Cruise Control System or Speed Limiter

PREVENTIVE ANTI-JERK

The main objective of the preventive anti-jerk function is to decrease discomforts of driver during depress the
accelerator pedal and during release the accelerator pedal.
The abrupt change of torque are delivered by engine excites a torsional natural frequencies of drive-line. It
causes vehicle jerking and acceleration fluctuations. And they are causes of perception and assessment of
performance and comfort for driver and the passengers.
The purpose of this function is to limit drive-line torque excitations. In fact, the engine torque set point is filtered
according to requirements of driveability.

TURBOCHARGER BOOST CONTROL

EC9-28

< SYSTEM DESCRIPTION >

[R9M]

SYSTEM

TURBOCHARGER BOOST CONTROL : System Description

INFOID:0000000010308979

DESCRIPTION

Turbocharger is used to increase the air pressure entering the engine. The turbocharger has two separate
chambers. The turbocharger consists of the following components:
• A chamber linked to the engine exhaust gas system
• A chamber linked to the engine air inlet system
• A turbine and a compressor, joined together by shaft.
The turbine, driven by exhaust gases, drives the compressor which compresses the inlet air.

CAUTION:

To stop the engine immediately after high-load driving, park the vehicle with the engine at idle before
turning OFF the ignition switch.
The boost pressure control is able to increase the manifold pressure with respect to the engine operating
point. The system has an electric solenoid valve connected on the vacuum circuit to control the flow of exhaust
gases through the turbine in order to generate high pressure in the boost circuit.

EGR SYSTEM

EGR SYSTEM : System Description

INFOID:0000000010308980

DESCRIPTION

EGR (Exhaust Gas Recirculation) system reduces NOx emissions and improves fuel efficiency by recirculat-
ing exhaust gas into the intake manifold.
This engine has two EGR systems (low pressure and high pressure), and one of them is selected depending
on condition.

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SYSTEM

EC9-29

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The purpose of the low pressure EGR is to decrease fuel consumption.
The low pressure EGR system and the high pressure EGR system are not activated simultaneously.

LOW PRESSURE EGR SYSTEM

The low pressure EGR system recirculates exhaust gasses in the downstream DPF (Diesel Particulate Filter)
to the upstream turbocharger of intake air passage.
If EGR conditions are satisfied when engine coolant temperature is more than 70

°

C (158

°

F) and intake air

temperature is 20

°

C (68

°

F), the opening angle of the exhaust throttle valve is reduced and the low pressure

EGR volume control valve angle is adjusted to control EGR for achieving an appropriate EGR rate.

HIGH PRESSURE EGR SYSTEM

High pressure EGR system recirculates exhaust gasses in the exhaust manifold to the intake manifold.
If EGR conditions are satisfied when engine coolant temperature is less than 30

°

C (86

°

F), the opening angle

of the throttle valve is reduced and the high pressure EGR volume control valve angle is adjusted to control
EGR for achieving an appropriate EGR rate.

EGR COOLING SYSTEM

The EGR cooler bypass is controlled by ON/OFF solenoid valve, connected to the vacuum circuit. Control is
determined according to the engine coolant temperature, intake air temperature, and the engine operating
point. The gases flow through the cooler during the EGR activation, except when the engine is cold; otherwise,
they go through the bypass. There is also a regular bypass activation function to prevent its clogging or jam-
ming.

THROTTLE CONTROL

THROTTLE CONTROL : System Description

INFOID:0000000010308981

DESCRIPTION

This engine has two throttle valves. One of them is installed to the upstream of the intake manifold on the air
intake line and used for the high pressure EGR control and smooth engine stop. The other throttle valve is
installed to the downstream of DPF (Diesel Particulate Filter) on the exhaust line and used for the low pres-
sure EGR control.
These valves are normally open.

ELECTRIC THROTTLE CONTROL ACTUATOR

• During high pressure EGR control, the electric throttle control actuator reduces the opening angle of the

throttle valve and lowers pressure around the EGR feed port so that intake EGR gasses can be efficiently
taken in.

• When ignition switch is turned OFF, throttle valve is closed to stop the engine smoothly.
• In DPF regeneration mode, fresh air flow control uses only electric throttle control actuator (EGR valve is

fully closed).

EXHAUST ELECTRIC THROTTLE CONTROL ACTUATOR

The exhaust electric throttle control actuator reduces the opening angle of the exhaust throttle valve and intro-
duces exhaust gasses to the low pressure EGR system.

SWIRL CONTROL SYSTEM

SWIRL CONTROL SYSTEM : System Description

INFOID:0000000010308982

DESCRIPTION

EC9-30

< SYSTEM DESCRIPTION >

[R9M]

SYSTEM

The intake manifold runner control valve mounted on the intake manifold generates swirl flow in the combus-
tion chamber. This swirl flow allows air mixture to become even, enabling the obtainment of the steady com-
bustion.

ENGINE TORQUE CONTROL

ENGINE TORQUE CONTROL : System Description

INFOID:0000000010308977

SYSTEM DESCRIPTION

The torque function can be explained by the following:
• Accessories torque management
• Engine torque losses
• Minimum available torque
• Maximum available torque
• Fast set-points to complete torque request
• Final torque requests setting

ACCESSORIES TORQUE MANAGEMENT

Air Conditioning Power

The amount of power absorbed by the air conditioning is useful for the engine control to compute the torque
requirement for air conditioning. Therefore, ECM can adapt dynamically the engine speed regulation depend-
ing on the load variations.
The power absorbed by the air conditioning depends on the refrigerant pressure and the compressor speed.
The air conditioning system power correction for idle speed regulation avoids engine speed undershoots and
overshoots at the compressor compressed volume variation.

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