4410500120 Distance Sensor

WABCO distance/height sensor (ride-height sensor) for vehicles equipped with ECAS (Electronically Controlled Air Suspension) on MAN TGA, TGX, TGS, and bus platforms. The sensor uses a rotary potentiometer mechanically linked to the axle via a push-rod and lever arm to measure the current suspension height continuously. This analogue voltage signal is fed to the ECAS electronic control unit, which compares it against the programmed target height and commands the air spring inlet or exhaust solenoid valves to raise or lower the chassis accordingly. Used for automatic level control under varying loads, kneeling function on buses, and dock-height memory positions on distribution trucks. Sensor failure or a broken linkage arm typically triggers ECAS fault code 00416 or similar and causes the suspension to freeze at current height or default to the transport height failsafe. Before replacing the sensor, inspect the mechanical linkage — a bent rod or worn pivot mimics sensor failure and is a significantly cheaper repair. Confirm the replacement sensor's electrical connector matches the vehicle harness before ordering.