2007 BMW 525xi with 93,500 miles.
Infamous trifecta lights (ABS, DSC, 4X4, BRAKE, EBV).
I replaced the following:
1. Transfer case
2. Transfer case motor
3. ABS/DSC module
4. DSC module (under passenger seat)
5. Replaced transfer case fluid
I cleaned the steering angle sensor and throttle. All speed sensors are working fine.
The same codes keep coming back:
5208 - ABSENT - VTG (Transfer Box): supply of servomotor
5F39 - PRESENT - Dynamic Stability Control (DSC): VTG (Transfer Box): internal
I took this car to one BMW dealership, one independent auto shop (that specialize in euro cars), and 2 independent mechanics, and NONE could figure out what's wrong with it. It really boiled down to them guessing the issue and charging an arm and leg to fix it.
Very frustrating 😤 , and I'm ready to abandon this stupid car and set it on fire.
Does anyone have any idea what could be triggering these codes?
This may sound dumb, but check the pins and connectors for any bent or loose pins and connectors. Also make sure the wiring to the modules under the seat aren’t too tight, that there is a little bit of slack. If the wiring is too tight, it could come loose when you hit a bump in the road.
BTW, it’s typical BMW dealer to go for the most expensive items first to replace, rather than do a proper diagnosis. For example, my fan on my X5 was continually running. I already knew the problem it was the thermostat. But I took it in to the dealer because of a separate recall, and just for fun, played dumb to see if they could diagnosis the problem. They said the actual fan needed to be replaced. Went down the street to an independent mechanic to get it fixed, and it was indeed the thermostat. That is a difference of thousands of dollars in parts and labor. The dealer will milk you for every last dime you have, and won’t fix your problem.
They checked all the wiring and modules. They were still working correctly. However, no one could figure out what was wrong. The dealership said the remanufactured transfer case was bad, so I had it replaced by the independent mechanic with another one, and the lights still came back.
I took it to an indy shop for German cars, they said it was the transfer case motor. So I paid my mechanic to replace the motor with a new one and reprogram it. But it still didn't resolve the issue.
Next, I took it to an independent mechanic that has experience fixing BMWs. He checked everything but couldn't figure it out. He replaced the ABS/DSC module and the DSC module. Aaaand the lights came back after a month with the same codes.
I paid my mechanic to clean the steering angle sensor and throttle, reprogram it, and see what happens. It didn't resolve the issue.
Took it back to the indy shop, and they said the transfer case motor was faulty. So I had it replaced AGAIN, and it didn't resolve the issue. 
Now they're saying it's the transfer case again!!!!
I recommend checking it yourself. See it with your own eyes. It should be relatively easy to look under the seat. It’s ridiculous, I know, but sometimes the simplest things can solve the problem.
One more thing to check. Check your tires. Make sure they are all facing the right direction, that they are all the same brand, and they are all relatively the same age, with the same wear.
I haven’t heard this for BMW, but another make has transfer case issues because they out in a random tire when a tire went flat. The tires need to be the same.
I actually did attempt to fix it myself before giving up and taking it to the dealership. All tires are the same, and have plenty of tread left. With each mechanic giving false diagnosis, I don't have much confidence in keeping this car any longer. I have a hunch it could be the main computer.
I've heard of newer Jeeps having transfer case issues due to different tire brands installed.
Totally. The jeeps is what gave me the idea for the BMW.
or if you planning to junk it... ignore and error codes and drive it till shes blows.. another junkyard collection. and buy different brand that is more reliable
Do you have any idea how difficult it is to comprehend your posts? Would you like an English tutor?
Take a deep breath ITWT. This will pass.