Short Description

Short Description





Overview











General





The Bosch ME 9.6 engine management system can be used for the engine variants with either 230 hp or 250 hp, although with different software content. The main task of ECM is to regulate torque (air mass), fuel and ignition. The control module is mounted on the plenum chamber of the intake manifold and is connected via two 64-pin connectors - one to the car's wiring harness and one to the engine's wiring harness.

The software in ECM can be updated via SPS.

Engine Torque





ECM ensures that the correct engine torque is achieved during any driving condition. It does so by combining all external torque requests (accelerator pedal, cruise control and TCS/ESP) with the internal ones. The internal torque requests (e.g. idle control) can be positive or negative (limiting). Some examples of limitations are maximum permissible torque or maximum permissible vehicle speed. When the external and internal torque requests are compiled, a result is calculated, i.e. requested engine torque in Nm. This is then converted to necessary (requested) air mass per combustion (mg/c) for the actual point of operation.

The requested air mass is converted to:
^ Throttle area request
^ Turbo request
^ Camshaft position

Ignition





ECM uses the actual air mass per combustion and engine speed to calculated ignition timing. Ignition timing is retrieved from a matrix in which air mass per combustion and engine speed indicate a specific value. This value then undergoes a number of corrections based on operating conditions, e.g. coolant temperature and charge air temperature. The ignition coils are regulated based on the corrected value for camshaft angle and ignition timing. The value is calculated for each combustion to optimize function. The ignition coils have an integrated power amplifier.

Knock control





Combustion in a petrol engine can be of a good nature (normal combustion) or a bad nature (knocking). Knocking can be very damaging to the engine and must therefore be monitored. The engine is equipped with one piezoelectric knock sensor per cylinder bank. The sensor is mounted on the cylinder bank and can be equated to a microphone that listens to engine noise. Knocking generates characteristic noises that are caught by the sensors, which are connected to ECM.

Knock control is individual to each cylinder. This means that, for example, the ignition timing of a knocking cylinder can be temporarily retarded which the other cylinder retain their normal ignition timing. If ignition retardation does not stop the knocking, engine torque is reduced to prevent engine damage.

Note that it is completely normal to hear single knocks even though there is no fault. If the engine continually knocks loudly, however, there is a fault.

Continuous variable cam phasing (CVCP)





Continuous variable cam phasing (CVCP) is a system that makes continual variation of the intake camshafts' position, i.e. phasing, possible. The duration (the number of degrees the values are hold open) remains constant. It is the position of the cam lobes, i.e. the camshaft angles when the intake values open or close, that are different. This is controlled by ECM via hydraulic valves in order to obtain the optimal intake camshaft setting at any given operating point.

Since ECM regulates the hydraulic valves with a PWM voltage, the valves can be stepplessly moved into the requested position. To compensate for the oil delivery pressure, the engine is equipped with a pressure sensor that measures engine lubricating oil pressure.

CVCP has the following advantages:
^ High engine output
^ High engine torque over a broad rpm range
^ Reduced emissions, especially NOx
^ Reduced fuel consumption