Plugging in a trailer indeed disables the rear pdc. Sticking a plug in should do the trick.

Ok. I've got a fix for this issue now. As Flowerfred says if you plug a load into the electric outlet of the hitch mount, it automatically disables the rear PDC system. You even get a message on i-drive when you start the car !!

Since I've got a bike rack attached to my hitch, i dont need trailer lights. As such I purchased one of those 10 buck hitch covers with a break light. I disconnected the break light and put a 8 ohm, 20 w resistor for the load. The X5 must see a load on the outlet otherwise it wont turn off the PDC

All sorted ... no more annoying rear beeping sound.

Yay !!

sweet! thanks for this info. very useful. (but could it drain the power???)

Just curious. It must be reading voltage at start-up on the brake circuit. Because you must have your foot on the brake to start the car, that's the circuit they picked. Also, there may not be any other circuits active (depending on what type of connector you have). For example, if your lights are off, there may be no power to read. Once again though, the one circuit they know will be active is the brake light circuit. Have you tried to pull the plug after the car is started to see if the rear PDC stays off? That would be interesting.

y5choi - No it will only use power as long as the car is running and only when your foot is on the brake pedal.

Having a resistor connected to the hitch mount electrical outlet is no different from connecting a trailer lights. In fact less power will be drawn because its just a small current draw.

I'll give it a try when I get a chance !

*update* If you disconnect the plug after the car has started PDC comes back on .... :-(

Doesn't work for me.
 

I tow a boat and when backing up with the elec. plugged in the rear PDC keeps on beeping. Hitch installation problem?

Investor,
Do your brake lights work on the boat trailer?

One thing I can tell you is, when the dealer installed the OEM hitch mount, the car needed software coding to let the cars electronics know there is a hitch installed. My thinking is, this has something to do with the car switching the rear PDC off when something is connected to the hitch electrical outlet.

Can't you just deselect PDC in Idrive?