CAN bus fault

[cla67]

I took my 2007 3.0 in to have the OEM hitch module programmed to the vehicle recently (I did the installation myself) and ended up with a slew of electrical issues. I was told the battery needed replaced before they could do any programming since it wouldn't hold a charge. It had died a couple of times on me in the few weeks preceding this so that didn't seem out of line.

The next day I received a call that my x5 was dead, system crash. Not even the diagnostics would run. Short version of what happened next: they replaced two ingnition assemblies before getting the system up and then had to replace two EMF control units (EM brake) before being able to complete the hitch encoding. A little over 2 weeks for all this to transpire because they were getting their instructions from BMW.

A week and a half later, the instrument cluster lights up with check engine, brake, dsc, etc. I move the vehicle out of the driveway and turn off and back on. Red "brake" light is now the only thing illuminated. I set the brake just to see if it is working. Brake sets but won't release. I had to release it manually. Back to the dealer.

Short version of current situation:

Over 5 weeks now. The voltage on the CAN wiring is out of range. After all modules had been removed to check for the fault(there was no change in the voltage) BMW NA says that it must be a wiring short. Not covered by CPO warranty, so they say, even though it states "electrical" as covered. Have asked repeatedly to speak with the BMW NA rep without success. Was only given the number to their customer relations dept. So far I have authorized them to look for the wiring fault in the suspect places all with no success and to the tune of $1000. At one point the service rep. said that BMW had basically thrown up their hands. So much for trained factory technicians. After repeated questions about how they had decided this is a wiring fault and their testing procedures now BMW has suddenly come back with some other ideas they are currently trying. And, yes that is the short version.

Anyone else had this problem?

Even if normal wiring isn't covered, wouldn't the network wire used for diagnostics be considered part of that system? I had no issues, none, before the car was taken in for the hitch encoding.

My main concern is that they can't find the problem and just hand me the keys back... and still want their $1000.

Sorry for being long winded.