Hey guys,
Vehicle is a 2012 x5 35i

I posted this on other forums but feedback was not helpful. I fortunately happened to stumble upon this site specifically for X models, hoping someone has had a similar issue or could help. I am going to be as detailed as possible. So, here it goes.

A week ago, I parked the car, came back and upon starting the car, i got DSC and 4x4 on the dash (only these, no park or abs). I pulled out of my driveway, and once i put the car into gear, my car literally would not move faster than human walking speed. I tried flooring it, and when i did this, the dsc light would flicker (like it was "doing it's job). No feeling of abs pulse (although i did get this when i reversed). THe car just didn't want to move.

Pulled the car into my garage, and plugged in my scanner (a very fancy snap-on that is capable of reading everything). I got code 5dec (transfer case malfunction). I deleted this code, but it immediately came back once i tried to drive the car again.

Fast forward to a few days later when i decided to dig in to the car myself as i couldn't drive it to the nearest indy and dealer was backed for 3 weeks. I removed the abs module connector to see if there was anything funky there, and there wasn't. I left it unplugged, and tried to drive the car that way, and it worked. I was now able to drive the car, granted now I had abs, park, dsc, 4x4, airbag, etc lights on. No odd noises, no driving issues, nothing. Also, My speedometer is way off (it reads 35mph when I am going close to 60mph)

Now, I find it hard to believe my transfer case is bad, especially since its not making any grinding/howling noises. A little more digging in, and i found if i plug the abs module back in, but remove one of the fuses, I get the same results as leaving the abs module unplugged, except now my speedometer works, and I am able to drive around while reading live data from the abs module.

I decided to go to my Land Rover Indy, as all the BMW guys were backed up. He put the car on the lift and started to inspect. He spun the right rear wheel and it spun the left rear wheel in the opposite direction which is what it's supposed to do. Then he went to spin the front right wheel, and it did not spin the front left wheel? He said he is not sure about these awd bimmers, but on a rover, it will spin the other wheel. He exposed the front driveshaft, and if he spins either wheel, it will spin the front driveshaft. Now, we do have that 5dec code, which according to his autologic scanner, means DEC 5dec - clutch gearbox-ECU: clutch temporary () closed. rear-wheel drive!

So, he is not sure if this is hard programmed to act the way it is currently, or if there is a mechanical malfunction.

Here is another important piece of info, I plugged my scanner in, and while driving, I get speed readings from my rear wheel speed sensors, but my fronts remain at 0mph. This is with all fuses back in and module plugged in stuck in the 3mph speed limit. I find it hard to believe both of my front speed sensors went out at the same time.


Soooo, with all this info, what are your guys thoughts on this. Could it be the abs module. a sensor? etc.

THings I have done:

Checked battery, it is fine. Removed the transfer case actuator motor, and that is fine as well (it is the new style without the gears).