Performance Controls
Performance Controls
EWS Interface
The EMS2000 communicates with the EWS module prior to releasing injection and ignition. Upon receiving the proper Rolling Code from EWS, EMS2000 allows the fuel injectors and ignition coils to operate.
Transmission Control (ECVT Only)
As the driver moves the shift selector lever from park the EMS2000 looks for a brake signal before releasing the shift interlock relay. Upon receiving a valid brake input the shift interlock relay is released and the gear shift lever is moved into a drive position. The EMS2000 evaluates inputs from the crank sensor, the transmission temperature sensor and the transmission output speed sensor as well as the gear shift lever switches to make decisions for gear selection and programming. Instructions for gear control are passed from the EMS2000 through the GIU to the transmission.
A/C Compressor Control
A request from the IHKS/IHKA is passed via the K-Bus to the IKE and then over the CAN Bus to the EMS2000. The EMS2000 checks the signal from the A/C pressure transducer and if within range, activates the compressor relay. The EMS2000 signals the IHKS/IHKA that the compressor has been turned on.
As part of the compressor activation process, the EMS2000 slightly increases the idle speed to compensate for the increased engine load.
Torque Management
Internal combustion engines generate torque by being supplied with a correctly mixed quantity of fuel and air, which is ignited at a precisely calculated time. By varying the quantity of air/fuel and the timing of the spark, the torque output can be altered. However, altering the quantity of fuel relative to the airflow can adversely affect catalyst life, combustion chamber and piston temperatures.
Therefore, when the EMS2000 varies the torque in response to the demands of the previously mentioned systems, it achieves this by altering only the ignition timing and/or throttle position. Certain characteristics are involved in these two methods of torque alteration:
Ignition timing
Ignition Timing can be altered rapidly and gives an instant torque change however, because under normal circumstances the EMS2000 always ensures that the engine runs at peak efficiency.
Throttle position
By changing the Throttle Position {airflow) the engine torque can be increased or deceased. If airflow is increased or decreased the EMS2000 automatically maintains the correct fuel mixture by balancing the fuel input. Unlike the rapid torque change achieved by altering the ignition, changes in throttle position take longer to achieve torque variation. Each system can demand either a slow or fast torque variation.
Torque Control
The Engine Management System (EMS2000) has the ability to vary the torque output of the engine in response to demands from several systems. These demands can be divided into three categories:
- Engine running demands: torque variation is requested internally from within the EMS2000 to support the following:
- Idle Control
- Catalyst 'light up' and overheat protection
- Limp home control
- Powertrain and chassis demands: torque variation is requested externally from the following systems:
- Dynamic stability control
- Automatic Stability Control + Traction Control (ASC)
- ECVT Automatic transmission
- Cruise control
- Driver demand
The EMS2000 is programmed to decide which of the torque variation demands is the most important and will then act upon that demand. This task is performed by the EMS2000 'Torque Manager' which performs two main functions:
- Torque selection: this function decides which of the torque demands shall be acted upon.
- Torque co-ordination: this function determines the ignition and throttle settings needed to produce the required torque.