Throttle position
The engine management system contains a position sensor which provides information on the opening angle of the throttle. The engine control module distributes a throttle position signal to other systems, such as the automatic transmission.
The transmission control module receives the throttle position signal on pin 25 from pin 38 of the Motronic 4.1 (4-cyl.) engine control module, pin 82 of the Motronic 5.2 (6-cyl.) engine control module and pin 57 of the Saab Trionic. The signal is a 100 Hz PWM signal, the pulse ratio of which indicates the opening angle of the throttle. The pulse ratio varies from 9%% at idling speed up to 92%% at full load (wide open throttle).
The transmission control module uses the throttle position signal to control gear-shifting points and system pressure.
An incorrect throttle position signal will activate the limp-home mode.
Temperature signal when starting
An extra function is incorporated on models equipped with the V6 engine or turbo. When the ignition switch is turned to the Drive position and while the starter motor is turning the engine over, the engine control module applies 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 varying between 2%% and up to 8%%. The transmission control module identifies the pulse ratio and activates a specific gear-shifting program for a maximum of 60 seconds in order to activate the catalytic converter as quickly as possible.