Geely EC718 2009 Workshop Manual page 680

2-598 Control System JL4G15-D
Coolant Temperature
(°C/ ºF)
100/212
110/230
>?20/248
3. Vehicle Speed Compensation and Deceleration
Speed Adjustment
To improve the deceleration and stop driving performance,
when the vehicle is driving, the target idle speed increases by
100 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 the air-conditioning is turned on with the vehicle parking,
in order to compensate for the compressor power
consumption, when the coolant temperature is below 0°C / 32F,
the target idle speed increases by 50 rpm; when the coolant
temperature is above 0°C / 32F, the target idle speed increases
by 200 rpm.
5. Voltage Compensation
When the system voltage is lower than 11.5 V, and not restored
in 10 s, the system will increase the target idle speed by 250
rpm, in order to increase the amount of electricity generated.
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 is used to eliminate engine detonations that may
occur during the combustion to optimize engine power and fuel
economy. System can control different cylinder knocking
independently.
1. Knock Control Enable Conditions
–
The engine running time is longer than 2 s.
– The engine coolant temperature is higher than 70°C /158 ºF
– The engine speed is greater than 800 rpm .
2. Knock Control Mode
When a knocking occurs or is likely to occur, the system will
quickly delay the ignition advance angle. System-based spark
EC718/EC718RV EC715/EC715RV 10/2009
Target Idle Speed (rpm)
750
750
800
advance angle is either normal ignition advance angle or safety
ignition advance angle. Knock controlled speed is between
thees two.
– Steady-State Control
When the engine is running as per normal, ECM collects
and analyzes engine combustion signals filters knocking
signal through the knock sensor. Once the knock intensity
is higher than the acceptable limit, the system will rapidly
delay the ignition advance angle cylinder in which the
detonation happened, to eliminate detonation in the
following combustion. The ignition advance angle will be
back to normal angle gradually.
–
Transient Control
During a sudden acceleration or a engine sudden speed
change, detonation is likely to happen. The system predicts
the likelihood of detonation, and automatically delays the
ignition advance angle in order to avoid a strong detonation.
–
Rapidly Delayed Ignition Advance Angle
Once the system detects a detonation, according to
different engine speeds, the system rapid delays ignition
advance angle 3-5 degrees, and resumes to normal
controls in 2-3 s afterward.
–
Adaptive Ignition Advance Angle
Due to wear and tear after long-term use, there are
differences between the engines. When the system and the
engine are in initial use or ECM is supplied with power, the
engine detonation may occur. The system will record the
detonation, after a period of running, the system will
automatically generate an adaptive adjustment value of the
ignition (self learn value). When the engine is running in the
same conditions, the system will automatically advance the
ignition angle, to the detonation occurring.
System adaptive learn process is constantly updated with
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 compressor clutch and frequently on-off, once the system
enters into the Air-Conditioning switch off mode, ECM delays
for a specified period of time to control Air-Conditioning clutch
pull-in.
Engine