Motronic

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,[1] before being implemented on several Volvo[2] and Porsche[3]

2.1

The ML 2.1 system integrates an advanced engine management with 2 knock sensors, provision for adaptive fuel & timing adjustment, purge canister control, precision sequential fuel control and diagnostics (pre OBD-1). Fuel enrichment during cold-start is achieved by altering the timing of the main injectors based on engine temperature. The idle speed is also fully controlled by the digital Motronic unit, including fast-idle during warm-up. Updated variants ML 2.10.1 through 2.5 add MAF Mass Air Flow sensor logic and direct fire ignition coils per cylinder. Motronic 2.1 is used in the Porsche 4 cyl 16V 944S/S2/968 and the 6 cyl Boxer Carrera 964 & 993, Opel/Vauxhall, FIAT & Alfa Romeo engines.

2.3/2.3.2

The M2.3.2 system was made for Audi's turbo 20V 5-cylinder engines mainly, but a variant was also used on the Audi 32V 3.6L V8 and a few Audi 32V 4.2 V8 engines. The turbo 5 cylinder version was the first time knock and boost control had been introduced in one ECU, though the ECU was really two computers in one package. One side of the ECU controlled the timing and fueling while the other side controlled the boost and knock control. Each side has its own Siemens SAB80C535 processor and its own EPROM for storing operating data. What made this ECU special was the use of two crank sensors and one cam sensor. The ECU used one crank sensor to count the teeth on the starter ring for its RPM signal, and the other read a pin on the back of the flywheel for TDC reference. This ECU was first seen when the 20V turbo 5-cylinder engine (RR Code) was installed into the Audi Quattro.

3.1

Compared with ML1.3, this system adds knock sensor control, purge canister control and start-up diagnostics. Motronic 3.1 is used in non-VANOS BMW M50B25 engines.[4]

3.3

Motronic 3.3 is used by BMW M60B30/B40 V8's in the 5, 7 & 8 series.

3.3.1

Motronic 3.3.1 is used in BMW M50B25 engines with VANOS.[4]

3.7

40.0

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40.1

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4.1

The Motronic ML4.1 system was used on Opel / Vauxhall eight-valve engines from 1987 to 1990,[11] Alfa Romeo and some PSA Peugeot Citroën XU9J-series engines.[12]

Fuel enrichment during cold-start is achieved by altering the timing of the main injectors based on engine temperature, no "cold start" injector is required.

5.2

Motronic 5.2 was used in the BMW M44B19 engine. Compared to 1.7, Motronic 5.2 has OBD-II capability and uses a hot-wire MAF sensor in place of the flapper-door AFM.[4]

5.2.1

Motronic 5.2.1 was used in Land Rover Discovery Series II and P38 Range Rovers that were built starting with late 1999. It was only used in cars equipped with V8 gasoline engines. This variant of the engine management system was adapted for off-road use. Unlike the Motronic system in BMW sedans, that uses a chassis accelerometer to differentiate between misfires and rough road, the Land Rover version used signal from ABS control unit to detect rough road conditions. This version of the system was integrated with body control module and anti-theft system.