Throttle actuator: Notes

The electromotive throttle actuator is secured to the intake plenum.

A throttle valve is necessary for all diesel engines equipped with a particulate filter system. The throttle valve chokes the intake air to ensure that the necessary increased exhaust-gas temperatures required for regeneration of the particulate filter are reached.

The throttle-valve actuator closes when the engine is switched off. This counteracts the engine's tendency to vibrate during the shutdown phase.

Yet another function is preventing the engine from overrevving. When the DDE Digital Diesel Electronics system detects increases in engine speed although no corresponding rises in the injection quantity have occurred, it responds by closing the throttle valve to limit engine speed.