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. It was then used in the Audi 200 20V turbo until 1991 when the Audi S4 was introduced and the ECU received several upgrades, including migration from a distributor-based ignition to coil on plug sequential ignition and an added overboost function. This ECU ended in 1997 when the last Audi S6 rolled off the assembly line. This ECU was also used in the legendary Audi RS2 Avant. The V8 version of the ECU was only single processor based while retaining all the same features of the turbo 5-cylinder ECU less the boost control. The 3.6 V8 version had a distributor-based ignition system and was upgraded around the same time to coil on plug as its 20V turbo counterpart in 1992–1993. 2.5 Was introduced in 1988 in the Opel Kadett E GSi 16V C20XE engine. Sequential fuel injection and knock control. 2.7 Late '80s and early '90s, various Ferrari. Some Opel / Vauxhall (C20LET engine). 2.8 Successor of the Motronic 2.5. Was used from 1992 at Opel C20XE engine. Major change was the introduction of DIS ignition. Was also at Opel V6 engine C25XE (1993, Opel Calibra (also X25XE), Opel Vectra A) used. Modified as M2.8.1 (1994) for X30XE and X25XE (Opel Omega B). M2.8.3 engine X25XE (Opel Vectra B) and X30XE (Opel Sintra). Motronic 3.x Motronic M3.x is powered by i196 microcontroller with code in flash memory ranging from 128kB to 256kB. 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. 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. 3.7 Motronic 3.7 is used in the Alfa Romeo V6 engine in the later 12 valve 3.0L variants, replacing the L-Jetronic. 3.7.1 Motronic 3.7.1 is used in the Alfa Romeo V6 engine in the 24 valve variants. 3.8.1, 3.8.2, 3.8.3, 3.8.4 Motronic M3.8x is used in many Volkswagen/Audi/Skoda vehicles Motronic 4.X Motronic M4.x is powered by various i8051 derivatives made by Siemens. 40.0 ?? 40.1 ?? 4.1 The Motronic ML4.1 system was used