Motronic is the trade name given to a range of digital engine control units developed by Robert Bosch GmbH (commonly known as Bosch) which combined control of fuel injection and ignition in a single unit. By controlling both major systems in a single unit, many aspects of the engine's characteristics (such as power, fuel economy, drivability, and emissions) can be improved. Motronic 1.x Motronic M1.x is powered by various i8051 derivatives made by Siemens, usually SAB80C515 or SAB80C535. Code/data is stored in DIL or PLCC EPROM and ranges from 32k to 128k. 1.0 Often known as "Motronic basic", Motronic ML1.x was one of the first digital engine-management systems developed by Bosch. These early Motronic systems integrated the spark timing element with then-existing Jetronic fuel injection technology. It was originally developed and first used in the BMW 7 Series, before being implemented on several Volvo and Porsche engines throughout the 1980s. The components of the Motronic ML1.x systems for the most part remained unchanged during production, although there are some differences in certain situations. The engine control module (ECM) receives information regarding engine speed, crankshaft angle, coolant temperature and throttle position. An air flow meter also measures the volume of air entering the induction system. If the engine is naturally aspirated, an air temperature sensor is located in the air flow meter to work out the air mass. However, if the engine is turbocharged, an additional charge air temperature sensor is used to monitor the temperature of the inducted air after it has passed through the turbocharger and intercooler, in order to accurately and dynamically calculate the overall air mass. Main system characteristics Fuel delivery, ignition timing, and dwell angle incorporated into the same control unit. Crank position and engine speed is determined by a pair of sensors reading from the flywheel. Separate constant idle speed system monitors and regulates base idle speed settings. 5th injector is used to provide extra fuel enrichment during different cold-start conditions. (in some configurations) Depending on application and version, an oxygen sensor may be fitted (the system was originally designed for leaded fuel). 1.1 Motronic 1.1 was used by BMW from 1987 on motors such as the M20. This version was also used by Volvo from 1982-1989 on the turbocharged B23ET, B230ET and B200ET engines. The systems have the option for a lambda sensor, enabling their use with catalytic converter-equipped vehicles. This feedback system allows