Pump, Leakage Detection (6/202) [2019-2022, B4204T23; B4204T27 | 2020-2022, B4204T28; B4204T39]: Description

The leakage detection pump applies a vacuum in the fuel tank for leak diagnostics. It consists of an electrical air pump, a valve, and a heater element. It also has an embedded pressure sensor. When leak diagnostics are not active, the valve is held open to ambient air to normalize the pressure in the fuel tank.