How to Replace an Audi G28 Engine Speed Sensor Charles the Humble Technician teaches how to replace the G28 Engine Speed Sensor. This sensor is located at the top of the transmission above the flywheel ring gear. It transmits a signal the ECU via the grey wire (T55/49), then to https://carlocksmiths64375.tinyblogging.com/the-secret-secrets-of-audi-a1-key-73551491