Nissan Qashqai J11. Manual - part 181

ECH-22

< SYSTEM DESCRIPTION >

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SYSTEM

ECM controls the engine by various functions.

ENGINE SPEED CONTROL

ENGINE SPEED CONTROL : System Description

INFOID:0000000010379027

SYSTEM DESCRIPTION

The engine speed control consists of the following functions:
• Cranking and cylinder identification
• Curative anti-jerk
• Idle speed control
• Engine speed limitation
• Engine state

CRANKING AND CYLINDER IDENTIFICATION

ECM controls the engine speed during cranking.
ECM sets and resets fuel injection timing.
ECM decides engine speed in cranking by detections restart status and controls fuel injection quantity.
ECM identifies a cylinder without camshaft sensor.
The aim of this function is to confirm whether the phase is correct.
The gathering composed of five flywheel teeth is stored and measured for every each TDC (top dead center).
The engine speed must be up to around 300 rpm and less than around 5000 rpm.
This function is functional 95% of the time.

CURATIVE ANTI-JERK

This function aims to smooth the engine speed through torque corrections out of idle engine speed regulation.
The torque correction is made by the anti-jerk function to damp the engine speed vibrations caused by the
drive-line vibrations.

IDLE SPEED CONTROL

ECM calculates the engine idle speed set point and maintains the engine speed in order to follow the set point.
The engine idle speed set-point is computed from following load and signal:
• Post treatment

Function

Reference

ENGINE SPEED CONTROL SYSTEM

ECH-22, "ENGINE SPEED CONTROL : System Description"

POWERTRAIN COORDINATION CONTROL

ECH-23, "POWERTRAIN COORDINATION CONTROL : System 
Description"

INTAKE AIR SYSTEM

ECH-24, "INTAKE AIR SYSTEM : System Description"

VARIABLE VALVE TIMING CONTROL

ECH-24, "VARIABLE VALVE TIMING CONTROL : System De-
scription"

TURBOCHARGER BOOST CONTROL

ECH-25, "TURBOCHARGER BOOST CONTROL : System De-
scription"

ENGINE TORQUE CONTROL

ECH-25, "ENGINE TORQUE CONTROL : System Description"

COMBUSTION CONTROL

ECH-27, "COMBUSTION CONTROL : System Description"

AFTER TREATMENT SYSTEM

ECH-31, "AFTER TREATMENT SYSTEM : System Description"

COOLING FAN CONTROL

ECH-31, "COOLING FAN CONTROL : System Description"

THERMOSTAT CONTROL

ECH-31, "THERMOSTAT CONTROL : System Description"

ENERGY MANAGEMENT SYSTEM

ECH-32, "ENERGY MANAGEMENT SYSTEM : System Descrip-
tion"

STOP/START SYSTEM

ECH-33, "STOP/START SYSTEM : System Description"

AUTOMATIC SPEED CONTROL DEVICE (ASCD)

ECH-40, "AUTOMATIC SPEED CONTROL DEVICE (ASCD) : 
System Description"

SPEED LIMITER

ECH-41, "SPEED LIMITER : System Description"

GEAR SHIFT INDICATOR SYSTEM

ECH-42, "GEAR SHIFT INDICATOR SYSTEM : System Descrip-
tion"

CAN COMMUNICATION

ECH-42, "CAN COMMUNICATION : System Description"

SYSTEM

ECH-23

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- Catalyst warm-up
• Electric consumers
- Cooling fan
- Power window
- Air heater (air conditioning system)
- 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
- Intake manifold pressure sensor signal
The final engine idle speed set point is computed from each consumer

′

s engine idle speed set point:

• Three correction torques for idle speed regulation are computed:
- Proportional
- Integral
- Derivative
• 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:0000000010379028

SYSTEM DESCRIPTION

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

ECH-42, "GEAR SHIFT INDICATOR SYSTEM : System Descrip-

tion"

.)

POWERTRAIN COORDINATION INPUTS

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

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.

ECH-24

< SYSTEM DESCRIPTION >

[HRA2DDT]

SYSTEM

Abrupt change of torque are delivered by engine excites a torsion natural frequencies of drive-line. It causes
vehicle jerking and acceleration fluctuations. And they are causes of perception and assessment of perfor-
mance 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.

INTAKE AIR SYSTEM

INTAKE AIR SYSTEM : System Description

INFOID:0000000010379029

THROTTLE CONTROL

The aim of electric throttle control actuator is to manage intake air quantity.
In normal operating conditions, the intake air flow is directly linked to the required engine torque. (For details of
engine torque control, refer to 

ECH-25, "ENGINE TORQUE CONTROL : System Description"

.)

ECM learns the fully closed position of the throttle valve by monitoring the throttle position sensor output sig-
nal.

Standard Operating Phase:

In standard operation condition, as the engine is running, ECM controls the throttle valve position according to
realize the required intake air flow.

Corrections and Limitations:

During regulation, ECM also performs the following tasks:
• Prevent the flap oscillations to prevent unwanted engine torque change.
• Prevent mechanical stress of the component by limiting the flap speed around the maximum/minimum posi-

tion.

• Prevent acoustic issues by limiting the throttle opening at certain engine speeds and during engine stop.

Learning Phase:

ECM learns fully closed position and limp-home position of the throttle valve and checks their validity. During
this phase, the component reaches its closed position 3 times then the limp-home position 2 times. This phase
occurs in the following conditions:
• At vehicle first IGNITION SW ON.
• When ECM has replaced or reprogrammed
• When the teach-in (s) has been reinitialized by CONSULT.

Limp-home Position Checking Phase:

When engine is stopped, ECM checks that the limp-home position did not change since the last learning
phase. During this phase, throttle valve reaches the limp-home position 4 times.

CALCULATION OF THE AIR FLOW

The aim of the Air System Function is to command the Throttle Flap in order to realize the Torque Demand.

The Mass Air Flow Set-point

The Mass Air Flow set-point comes from the Torque Structure Function. A Canister Purge Mass Air Flow Cor-
rection is taken into account in order to correct the set-point.

The Air Flow Calculation

ECM takes into account the manifold pressure, the boost pressure, and the inlet air temperature to have the
mass air flow per unity of throttle Efficient Area.

VARIABLE VALVE TIMING CONTROL

VARIABLE VALVE TIMING CONTROL : System Description

INFOID:0000000010435873

DESCRIPTION

A variable valve timing control allows to move the angle of distribution according to the engine speed and to
the load.
By choosing the good compromise of adjustment the shifter of camshaft allows:
• to improve the stability of the slow idle speed
• to decrease the consumptions
• to decrease polluting broadcasts
• to increase the performances of the engine
This system consists of the following:
• Shifter(s) (integrated cam sprocket)

SYSTEM

ECH-25

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• Control solenoid valve(s)

COMPONENT DESCRIPTION

Shifter

• It is a hydraulic shifter: the rotor (in 4 pallets) moves in the stator by

rotation under the influence of the oil pressing.

• The rotor is fixed to the tip of the camshaft.
• A pawn of locking with conical tip (accommodated in the rotor)

maintains the phase shifter in position by default in absence of
pressure of oil (phases of driving starting up).

The levying of this pawn is ordered by the coming oil pressing of the
circuit advance or the circuit delay.

CONTROL OUTLINE

The closed roop regulation works as follows:
1.

A system of target/sensor sending to ECM the position of the camshaft.

2.

ECM transmits an opening or locking request signals to the Intake/Exhaust Valve Timing Control Solenoid
Valve.

3.

The resultant oil pressure in the shifter between the rotor and the stator shifts the camshaft.

TURBOCHARGER BOOST CONTROL

TURBOCHARGER BOOST CONTROL : System Description

INFOID:0000000010435871

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.

CONTROL OUTLINE

The boost pressure control adequately adjusts intake manifold pressure according to various driving condi-
tions.
This system has a turbocharger waste gate control solenoid valve. The turbocharger waste control solenoid
valve opens/closes the waste gate valve to adjust exhaust gas flow passing through the turbocharger turbine.
Through this operation, the turbocharger waste control solenoid valve controls boost pressure.

ENGINE TORQUE CONTROL

ENGINE TORQUE CONTROL : System Description

INFOID:0000000010379030

SYSTEM DESCRIPTION

The torque function can be explained by the following:
• Accessories torque management
• Minimum available torque
• Maximum available torque
• Fast set-points to complete torque request
• Slow set-points to complete torque request
• Final torque requests setting
• Injection cut
• Full load
• Torque correction in the knocking zone

ACCESSORIES TORQUE MANAGEMENT

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