wabsage

Just bought a 2004 530i sport package, no bluetooth or nav, my first BMW. While test driving I actually turned off the radio so that I could listen for other problems. Well after making the deal with the BMW dealer, I noticed on the drive home that the radio sounded like an old vinyl record that was skipping. Since it's an 04, no warranty.

But after reading on here about TCU issues I unplugged the TCU and the problem went away. I do get the SOS inop light when I start the car, but the audio sounds great now.

So, here's my question. After complaining to the dealer about the problem they've offered to split the repair cost($1239.43) with me. I think they're great for offering to do that much. But is it worth the money? Any problems with just leaving the TCU unplugged?

healthservices

With a new updated tcu you may have the option to turn on Bluetooth. I'd do it.

Welcome to the forum!

wabsage

Thanks for the welcome! I also have been thinking that if the new TCU supported bluetooth that it would be worth the cost. However, I've also seen a Bluetooth retrofit from Bimmernav that is ~$675 and I was thinking that my money would be better spent on a sure thing rather than hoping the new TCU had bluetooth and the dealer was willing to turn it on.

rmcd

Welcome to the forum. As you found, it's a treasure trove of advice and information.

I would simply negotiate with the dealer to ensure that it's a newer TCU and that they turn on the Bluetooth support. If they're in there already it shouldn't be that much more effort. While under warrenty, I was able to pretty simply negotiate something similar.

I agree the dealer has been pretty good by offering to split the cost but at the same time, this is the kind of problem that you won't find with a normal check while considering a purchase. I kinda think they've got a lot of responsibility on this - which they seem to be acknowledging.

When you get a chance, you should update your profile with your location. The location sometimes helps to tune the advice that members give.

Good luck.

KEDA

What is the TCU and how do I unplug it?

wabsage

Keda - After much research on this forum I've learned this, the TCU is the Telematics Control Unit. It's located in the trunk, mounted on the driver's side rear wheel well. It's a rectangular box about 5" x 12" x 1" thick. You have to take out the trunk panels in order to see the TCU. It's held in place with 4 nuts, I removed the TCU to make it easier to disconnect the bottom plug (white, with about 30 wires in it). There are 4 connections on top (leave those alone). And that's it.

Also, you do this at your own risk! I've only done this for a short time to test. I'm not sure if there will be any problems if you leave this disconnected for any length of time.

Howitzer

I been on this site 2 years and I still don't know what the hell the TCU's main function is.

wabsage

Talked with my dealer today. They seem to think the problem is in the MASK computer (?) rather than the TCU. I did explain that I had tried disconnecting the TCU and the problem went away. That surprised them and they wanted to check in to this problem a bit more....

Hopefully, I'll hear from them tomorrow.

ulvit

Yer, the TCU you have explained can be turned on via coding at and only at the dealer....there are computers that can connect to this system, but you cant operate the software unless you have a degree is something stupid.. hahahah
But well worth it.