Introduction | 3B Description | ABY Changes | Schematics | Boost Control | Diagnostics

Bosch Motronic Info

Motronic Schematics

It is no secret that the wiring schematics for the Audi S2 are notoriously hard to get your hands on... They are generally only available in the domain of dealerships and a small number of Audi specialists as addendums to the generic Audi 80/90 wiring info. It is hoped that the schematics presented here go a long way to helping S2 owners with a more complete understanding of the ECU wiring and to enable some simple fault diagnosis.

The schematics for the 3B and ABY engine are distilled from a combination of the various sources I was able to track down for the North American implementation of the 3B and AAN engines. It is hoped that these sheets are more user friendly than the full set of S2 schematics as they focus only on Motronic related components.

The fuse locations on these schematics reflect the 3B and ABY wiring on the S2 to the best of my knowledge.

The schematics linked below do not include wiring colour information at this time. Once again - I cannot guarantee that these schematics will match your S2 exactly because of wiring changes that might have occurred across the different model years, countries and option packages. For wire colour information you need to check with the full blown schematics on the wiring pages .


3B Motronic Schematic ABY & ADU Motronic Schematic


As for ECU pinouts, the links below will provide all the info you need to debug any wiring issues with the 3B and ABY engines.


Several of the ECU output actuators and solenoids are protected by fuses in the main fuse box. The table below identifies the purpose of each ECU fuse to assist fault finding.

Last Updated 4th October 2003