Geely Emgrand X7. Manual part — 165

F. Deceleration

Fuel

Cut-off

Adjustment

When the system exits the deceleration fuel cut-off control mode, the ignition angle will be
adjusted to make the throttle close transition smooth.

G.. Air-Conditioning

Control

Adjustment

When the engine is idling, turn off the Air-Conditioner. The ignition angle will be adjusted to
make the engine run smoothly.

2.12.3.4 Electronic Throttle Body Function Restrictions

1. Forced Shut Down Mode

When ECM reports a malfunction or that the intake or throttle air flow control has a problem, the
control strategy is to stop the fuel supply and the ignition, and to close the throttle as well as to
shut down the engine.

2. Forced Idle Speed Power Management Mode

When the engine is idling, ETC system can not reliably use the throttle to control engine power. At
this point, the ETC cancels the throttle control. The throttle opening returns to the default position.
The engine power control is achieved by stopping one cylinder fuel injection and delaying the
ignition angle.

3. Forced Idle Speed Mode

When the driver's intention can not be reliably detected, such as that all pedal signals are lost, the
vehicle only maintains cooling, heating, electricity supply and lighting functions with engine
idling. If pressing the acceleration pedal, there is no response on the engine, then in this mode the
vehicle can not be driven.

4. Restricted Power Management Mode

ETC system can not use the throttle to control engine power. In this mode, the system determines
whether the engine is at idle speed or is accelerating based on the acceleration pedal signal. The
system controls engine power output by shutting down the engine, or by stopping a cylinder fuel
injection, or by delaying the ignition. The engine output fluctuation is obvious. Working a long
time in this mode would be harmful to the engine emission system. The model ensures that the
vehicle is barely enough to be driven, but difficult to control in normal traffic or climbing on a
steep slope.

5. Mode when the reliability of determining the drive intention is decreased or when the

system can not achieve high power output

When the two acceleration pedal position sensors input signals have two much difference, the
engine's output torque is limited. The engine's response to the pedal position change is much
slower. The driver may feel that the engine power output will be significantly weakened, but the
vehicle will be still able to drive in normal traffic.

659

2.12.3.5 Idle Speed Control

Idle speed air flow control is that the
engine control system maintains the
target idle speed when throttle body is
fully closed. The system maintains a
smooth transition with the throttle
body fully closed to prevent the stall.
When the engine load changes at idle
speed, system maintains a steady
engine speed.

1. Target Idle Speed Calculation

速度补偿

减速调节

基本目标怠速

实际控制目标怠速

目标怠速计算

空调补偿

电压补偿

FE02-8040b

2. Basic

Target

Idle

Speed

At different coolant temperatures, the basic target idle settings are as follows:

Water Temperature/
Atmospheric Pressure

45 55 65 75 85

95 105

-40

1350 1350 1350 1350 1350

1350 1350

-30

1350 1350 1350 1350 1350

1350 1350

-20

1350 1350 1350 1350 1350

1350 1350

-10

1350 1350 1350 1350 1350

1350 1350

0

1250 1250 1250 1250 1250

1250 1250

10

1200 1200 1200 1200 1200

1200 1200

20

1200 1200 1200 1200 1200

1200 1200

30

1150 1150 1150 1150 1150

1150 1150

40

1000 1000 1000 1000 1000

1000 1000

50

950 950 950 950 950

950 950

60

850 850 850 850 850

850 850

70

750 750 750 750 750

750 750

Fundamental

objectives idling speed

Speed

compensation

Decelerating

adjusting

Actual control target

idlingspeed

Air-conditioning

compensation

Voltage

compensation

Target idling speed

calculation

660

80

750 750 750 750 750

750 750

90

750 750 750 750 750

750 750

100

750 750 750 750 750

750 750

110

850 850 850 850 850

850 850

120

900 900 900 900 900

900 900

3. Vehicle Speed Compensation and Deceleration Adjustment

To improve the deceleration and stop driving performance, when the vehicle is driving, the target
idle speed increases by 50 rpm higher than stopping idle speed. During the deceleration and
stopping, the speed gradually decreases to the parking target idle speed.

4. Air-Conditioning

Compensation

When turning on the air-conditioner at parking, in order to compensate the power consumption,
the target idle speed rises 20 rpm at the coolant temperature < 50 /122 ; rises 30 rpm at the

℃

℉

coolant temperature of 50 /122 ; rises 40 rpm at the coolant tempera

℃

℉

ture of 60 /140 ; rises

℃

℉

55 rpm at the coolant temperature of 70 /158 ; rises 70 rpm at the coolant temperature of

℃

℉

80 /176 ; rises 80 rpm at the coolant temperature of 90 /194 ; rises 100 rpm at the coolant

℃

℉

℃

℉

temperature of 100 /212 .

℃

℉

5. Voltage

Compensation

When the system voltage is lower than 12 V, and not restored in 10 s, the system will increase the
target idle speed by 300 rpm to increase the generated electricity amount. When the external
power load impacts the system, the transient voltage will fluctuate. The system will automatically
compensate for the air flow rate in order to curb the engine speed fluctuations.

2.12.3.6 Knock Control

Knock control function is used for eliminating engine knock which would occur during
combustion and optimizing power performance of engine and economical efficiency of fuel.
System can control different cylinder knocking independently.

1. Knock Control Enable Conditions

–

Engine running time is more than 2 s

–

Engine coolant temperature is more than70 /158 ºF

℃

–

Engine speed is more than 600 rpm

2. Knock Control Mode

When a knocking occurs or is likely to occur, the system will quickly delay the ignition advance
angle. System basic ignition advance angle is either normal ignition advance angle or safety
ignition advance angle. Knock controlled speed is between these two.

– Homeostatic

control

When the engine is running as per normal, ECM collects and analyzes engine combustion signals
and filters knock signal through the knock sensor. Once the knock intensity is higher than the
acceptable limit, the system will rapidly delay the ignition advance angle of cylinder in which the
detonation happened, to eliminate knocking in the following combustion. The ignition advance
angle will get back to normal angle gradually.

– Transient

control

During a sudden acceleration or engine speed change, knocking is likely to happen. The system
predicts the likelihood of knocking, and automatically delays the ignition advance angle in order
to avoid a strong knocking.

–Quickly delayed ignition advance angle

661

Once the system detects a knocking, according to different engine speeds, the system rapidly
delays ignition advance angle 3-5 degrees, and resumes to normal controls in 2-3 s afterward.

–

Adaptive control ignition advance angle

Due to wear and tear after long-term use, there is certain difference between the engines. When the
system and the engine are in initial use or ECM is resupplied with power, the engine knocking
may occur. The system will record the knocking, after a period of running-in, the system will
automatically generate an adaptive adjustment value of the ignition (self-learning value). When
the engine is running in the same conditions, the system will automatically make the adaptive
adjustment for the advance the ignition angle, to avoid the knocking occurring.

System adaptive learning is the constantly updating during the engine running.

2.12.3.7 Air-conditioning Switch off Control

In some cases, in order to ensure the engine power or protect the engine or protect the
Air-Conditioning system, ECM must stop the Air-Conditioning compressor working or prohibit
the Air-Conditioning system to start. At the same time, to prevent the frequently on-off of
compressor clutch, once the system enters the Air-Conditioning switch off mode, ECM delays for
a specified period of time to control Air-Conditioning clutch pull-in.

– Full-throttle Air-Conditioning Switch off Mode: Ensure the vehicle power.

The engine speed is less than 3,600 rpm.

No TPS fault

TPS is greater than 101%, and since the last time full-throttle air-condition-off, the TPS has been
less than this value

– Engine Speed Too High Air-Conditioning Switch off Mode: Protect the Air-Conditioning

system.

A/C off, the engine speed should be less than 5,800 rpm before the compressor is allowed to start.

When A/C is on, once the engine speed is greater than 6,000 rpm, the compressor will be switched
off.

– Engine Coolant Temperature Too High Air-Conditioning Switch off Mode: Protect the

engine.

A/C off, the coolant temperature should be less than 106°C (223°F) before the compressor is
allowed to start.

A/C on, once the coolant temperature is greater than 108°C (226°F), the compressor will be
switched off.

2.12.3.8 Canister Solenoid Valve Control

Canister solenoid valve controls the opening and closing event and time of the channel between
the canister and intake pipe, so as to control the amount and time for fuel vapor entering the
cylinders, therefore maximizing the decrease of the vehicle evaporative emissions, while
minimizing the impact on engine performance.

1. Working conditions of canister solenoid valve

In order to reduce the impact on the normal combustion and doing work from the fuel vapor
entering the cylinder, the following conditions must be met before the canister solenoid valve is
open:

–

System voltage is less than 18 V but more than 8 V

–

Engine coolant temperature is more than 0 (32 ?F)

℃

–

Engine intake air temperature is higher than 0°C (32 ?F)

–

non-correlation system fault

• Fuel

System

Malfunction

•

Fuel Pump Malfunction

662