chuckg

i"m looking for my TCU in a 04 545 and I was told it was in the rear quater panel. I found a fuse box. Is that also the TCU? if not, where is it. what does it look like. the reason I am trying to find is to see if I have bluetooth or not. is the BT symbol easy to spot? pls help

ademitt

The TCU is located in the trunk, left hand side behind the panels and covers. It is fairly long and slender and is fastened to the frame.

It is far easier to get the build date from the sticker on the driver's side door sill. If your car is a March 04 production, take down the last 7 digits of your vin and call your local BMW dealer. They can check the car history and tell you the exact date that the car rolled off the line. If your car was built after March 15th, 2004, you will have the updated TCU. You will only be required to enable BT via software update if it has not been already activated.

If your car is in the critical period of Mar 1 to 15th, you will need to get the part number off of the TCU housing to see if it is the updated version. This may be best done by your dealer as they have the part numbers for the older and newer versions. If you are really keen, you can search some of the posts from about 14 months ago when others (myself included) debated this issue to death on this forum. PN's were listed at that time as well IIRC.

chuckg

Thx for the info. My dealer said that the TCU would have a BT decal on it. Is that true? or can you only tell buy the part number. My car has a build date of 2/04 so I am just kind of hoping I get lucky.

ademitt

Given your build date, BT will work with your car but people will not be able to hear you when you speak using handsfree. The problem lies in that Assist is incompaitble with BT in the old TCU, hence the need to replace it. Unfortunately, even if you dump Assist you will still need to repalce the TCU to be able to use a BT phone.

My car was built on Mar 01/04 and I had the old TCU with the BT passkey card in the trunk. A car built on March 8th on this forum had the updated TCU. I am sure you will have the old part given a Feb build date.

You have two options, go with a Motorolla CPT 9000 phone that is not BT but fully compatible with your car in every other respect (including cradle and handsfree) or have the TCU replaced at your cost. If you have a good relationship with the service department they may cut you a deal on the parts but it still will be at least $1000 or so for the part. Remember, programming will be over and above this amount.

Now, if you could find a way to get the TCU replaced under warranty, that's a different story! Many have tried and a few have succeeded. In some cases, the TCU does not take the update of SW well and crashes and needs to be replaced. Find a way to get them to update your software under warranty (tell them that your idrive crashes and does not always boot back up) and see if that will do it for you.

Let us know how it goes.

znod

Your build date date (i.e., mo/yr) should be on your driver-side door pillar--if that helps.

chuckg

thx again. I have researched many previous threads and gotten most of my answers. has anyone succeeded in 'assisting' a TCU crash.

chuckg

TCU number 84-11-6-942-592. from what I've read this should not work, even though it does have the bluetooth symbol. any recent developments on securing a new one at BMWs expense?

ademitt

BMW has issued written instructions to their dealers via a SIB that states that older TCU's are to be replaced at the owner's expense in order to enable BT in pre 03/04 production vehicles. This directive has been out for some time now.

As I mentioned before, several members have had their TCU's replaced under warranty when the TCU crashed upon programming. If you were to get the cip software updated because your idrive was giving you problems for example, you may just get the TCU to crash and not be repairable. At that time, you would get one replaced under warranty. I am not aware of any other circustance where the TCU was replaced under warranty.

Peter530i

you guys just know everything. cool infos.....
I wish bmw techs would be as helpfull too

vern

BMW has issued written instructions to their dealers via a SIB that states that older TCU's are to be replaced at the owner's expense in order to enable BT in pre 03/04 production vehicles. This directive has been out for some time now.

As I mentioned before, several members have had their TCU's replaced under warranty when the TCU crashed upon programming. If you were to get the cip software updated because your idrive was giving you problems for example, you may just get the TCU to crash and not be repairable. At that time, you would get one replaced under warranty. I am not aware of any other circustance where the TCU was replaced under warranty.
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I had 4 TCU Units replaced at BMW's cost because of BMW Assist, SOS Malfunction and I'm going in again this coming Monday for the same thing.Probably change another TCU Unit. At $2000 + for each one.
cheers
vern