Monitoring function - pump current diagnosis

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2008 BMW Z4, 2008 BMW X5, 2008 BMW X3, 2008 BMW 528xi, and 2008 BMW 528i. However, it is still accessible from the selected car via links, so may be relevant.

P1434, P1447, P1448, P1449

In the reference measurement phase the current of the DM-TL is checked, if the current consumption is smaller than 15 mA a defect pump/motor is detected, and P1448 is stored. If a current consumption of bigger than 40 mA is measured also a defect pump/motor is detected, and the P1449 is stored.

After the reference measurement the electrical solenoid is switched and the venting system is tight. The solenoid is checked by comparison of the reference current and the idle current immediately after the solenoid has switched.

If the difference between the two currents (reference current - idle current) > 2 mA is not reached, the DTC P1447 is stored.

The P1434 fault code is set, if current fluctuations (caused by humidity in the DM-TL) > 1 mA are detected.