How to Replace an Audi G28 Engine Speed Sensor Charles the Humble Technician teaches how to replace the G28 Engine Speed Sensor. The sensor is situated at the top of the transmission just above the flywheel ring gear. It sends a message to the ECU via a grey wire T55/49, https://g28carkeys97431.gynoblog.com/29373882/what-is-audi-advanced-key-and-how-to-use-it