How to Replace an Audi G28 Engine Speed Sensor In this video Charles the Humble Mechanic demonstrates how to replace the G28 engine speed sensor. This sensor is located at the edge of transmission, above the flywheel gear. It transmits a signal to the ECU via a grey wire (T55/49), https://g28-car-key-solutions85680.blogs100.com/30282975/what-is-audi-advanced-key-and-why-is-everyone-talking-about-it