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Throttle position

Throttle position

The engine management system includes a position sensor that provides information on the opening angle of the throttle. The engine control module distributes a throttle position signal to all the other systems, such as the automatic transmission.

The transmission control module receives the throttle position signal on pin 25 from Motronic pin 52 and Trionic pin 57. The signal is a 100 Hz PWM signal, the pulse ratio of which specifies the opening angle of the throttle. The pulse ratio varies from 9% at idling speed up to 92% at full load.

The control module uses the throttle position signal to control shifting points and system pressure.

An incorrect throttle position signal will cause the transmission to go into limp-home mode.



Temperature signal on starting

Variants with turbo are also fitted with an extra function. When the ignition key is turned to drive position and when the starter motor is cranking, the engine control module sends an engine temperature signal to pin 25 instead of a throttle position signal. The signal is a 100 Hz PWM signal with a pulse ratio from 2% up to 8%. The transmission control module identifies the pulse ratio and activates a specific shifting program for a maximum of 60 seconds with the intention of igniting the catalyser as quickly as possible.