System Overview, Motronic 4.1

The Motronic 4.1 is an engine management system which controls ignition and fuel injection.





The Motronic 4.1 supersedes the Motronic 2.10 system on model year 1996 and later U.S. specification Saab 900 cars equipped with the B234 engine. Starting with M96, OBD II is scheduled for introduction in the US market. This entails the following component changes as compared with the Motronic 2.10:
^ Control module with 88-pin connector.
^ Oxygen sensor after the three way catalytic converter.
^ The oxygen sensors are grounded directly to the control module by a separate lead.
^ A number of sensors are fitted with different connectors and/or gold-plated pins
^ Rough road sensor.

In other respects, the engine management system is similar to the Motronic 2.10 fitted to Saab 900 cars equipped with the B234 engine.

IMPORTANT:
Illustrations showing the input and output stages of the control module and various components are drawn schematically to facilitate an understanding of how they work.

Saab Automobile AB does not vouch for the accuracy of the electrical layout.