How to Replace an Audi G28 Engine Speed Sensor Charles the Humble Technician shows how to replace the G28 Engine Speed Sensor. The sensor is situated near the edges of the transmission just above the flywheel ring gear. It transmits a signal to the ECU via a grey wire (T55/49) https://g28carkeys39791.isblog.net/who-is-the-world-s-top-expert-on-audi-a1-key-47076316