Bmw x5 e53 3.0d diesel m57 with a webaso heater running and draining the battery when the car is off and ghe key is removed. The unit is power contantly but is commanded to operate by the heating module in the spare wheel well. The module isn't being commanded on, and even if the wiring from the ecu is disconnected it will still run. Tje unit has some form of internal short causing it run all the time. The heater combustion blower fan in this case could be heard to be running. Unplugging the unit fixed the battery drain and saved this customer the cost of replacing the unit which is deemed unnecessary in some climates.
#x5 #bmw #bmwspecialist
Bmw X5 E53 Battery Drain Goes Flat Parasitic Draw