If the module is recognized by the vehicle, the rear PDC will not engage when a trailer is connected. That was my standard test.

If you are getting error messages with the module and before a trailer is connected, I would try coding it.

If you are not getting error messages with the module and no trailer, but then do get errors when a trailer is connected, I would check to see if you have LED trailer lights and if so use an adaptor.

I would expect to have to code a 2006 model

__________________
2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue