SSANGYONG KYRON 2007.04 Manual page 284

3) Idle Speed Controller
The idle speed controller consists of 2 principal modules:
- The first module determines the required idle speed according to:
The operating conditions of the engine (coolant temperature, gear engaged)
·
Any activation of the electrical consumers (power steering, air conditioning, others)
·
· The battery voltage
The presence of any faults liable to interface with the rail pressure control or the
·
injection control. In this case, the accelerated idle speed is activated to prevent the
engine from stalling when operating in degraded mode.
It is possible to increase or to reduce the required idle speed with the aid of the
·
diagnostic tool.
- The second module is responsible for providing closed loop control of the engine's idle
speed by adapting the minimum fuel according to the difference between the required idle
speed and the engine speed.
4) Flow Limitation
The flow limitation strategy is based on the following strategies:
- The flow limitation depending on the filling of the engine with air is determined according
to the engine speed and the air flow. This limitation allows smoke emissions to be reduced
during stabilized running.
- The flow limitation depending on the atmospheric pressure is determined according to the
engine speed and the atmospheric pressure. It allows smoke emissions to be reduced
when driving at altitude.
-
The full load flow curve is determined according to the gear engaged and the engine
speed. It allows the maximum torque delivered by the engine to be limited.
- A performance limitation is introduced if faults liable to upset the rail pressure control or
the injection control are detected by the system. In this case, and depending on the gravity
of the fault, the system activates:
· Reduced fuel logic 1: Guarantees 75 % of the performance without limiting the engine
speed.
Reduced fuel logic 2: Guarantees 50 % of the performance with the engine speed
·
limited to 3,000 rpm.
Reduce fuel logic 3: Limits the engine speed to 2,000 rpm.
·
The system chooses the lowest of all these values.
A correction depending on the coolant temperature is added to the flow limitation. This
correction makes it possible to reduce the mechanical stresses while the engine is warming up.
The correction is determined according to the coolant temperature, the engine speed and the
time which has passed since starting.
▶ Superchager Flow Demand
The supercharge flow is calculated according to the engine speed and the coolant temperature.
A correction depending on the air temperature and the atmospheric pressure is made in order
to increase the supercharge flow during cold starts. It is possible to alter the supercharge flow
value by adding a flow offset with the aid of the diagnostic tool.
09-17
1491-01
ENGINE D20DT
KYRON 2007.04