Flow Limitation - SSANGYONG Rodius 2012.07 Manual

15-18
C. 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, increase the idle speed to prevent the engine from stalling.
- 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.
D. 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 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.
E. 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