System Overview, Motronic 5.2

The Motronic engine management system mainly controls ignition and fuel injection.

The Motronic 5.2 supersedes the Motronic 2.8.1 system on model year 1996 and later U.S. specification Saab 900 cars equipped with the B258 engine.





Starting with M96, OBD II is scheduled for introduction in the US market. This entails the following component changes as compared with Motronic 2.8.1:
^ Control module with 88-pin connector
^ Oxygen sensors after the catalytic converters
^ A number of sensors are fitted with different connectors and/or gold-plated pins
^ A pressure sensor for the fuel tank
^ A shut-off valve for the evaporative emission canister's supply air
^ The oxygen sensors are grounded directly to the control module by a separate lead.

In other respects, the engine management system is similar to the Motronic 2.8.1 fitted to Saab 900 cars equipped with the B258 engine.