How to Replace an Audi G28 Engine Speed Sensor In this video, Charles the Humble Mechanic shows how to replace the G28 engine speed sensor. This sensor is situated at the edge of transmission just above the flywheel gear. It transmits a signal the ECU via a grey wire (T55/49) https://car-locksmiths13564.bloggazza.com/29177189/the-most-inspirational-sources-of-audi-a1-key