Motronic

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Motronic is an engine control unit, and was one of the first digital engine-management systems developed by Bosch. The basic idea behind the system was to fully integrate and regulate all major engine system parameters, thereby enabling fuel delivery and spark timing control functions to be controlled by the same unit, in an attempt to achieve optimum efficiency, driveability and power output potential. Early Motronic systems integrated the spark timing element with existing Jetronic fuel injection systems.

It was originally developed and first used in the BMW 7 Series^[1], before being implemented on several Volvo and Porsche^[2] engines throughout the 1980s. It was also used on turbocharged Audi Quattro models during the early 1990s.

1 Motronic 1.x
2 Motronic 2.x
3 See also
4 References
5 External links

[edit] Motronic 1.x

The components of the Motronic 1.x systems for the most part remained unchanged during production, although there are some differences in certain situations. The electronic control unit (ECU) 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 ECU.
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.
No oxygen sensor (system was originally designed for leaded fuel).
No knock sensor.