Hi Everybody,
I have 2001 325i e46 and its yellow brake and was coming up with a sound and shake from the driver side tire. I was making that scary sound and shake sometimes after 5 miles, sometimes 600 miles after. Of course it is very dangerous if you are driving on the highway with high speeds. Quick solution for this is disabling the DSC system, just press the DSC button and see the yellow tracking light comes up on the dashboard.
I read a lot of forum and talk about the dealer about this problem. They said Hyro system could be broken, or the sensors under the brake fluid, or speed sensors which are located on the tires and gave me an estimate which was almost $2000.
The first thing that I have done was cleaning the speed sensors on the tires. I thought that it solved the problem because nothing happened until 600 miles. Unfortunately, after 600 miles DSC and brake lights came up.
in my last appointment with the dealership I had a chance to talk with the mechanic. He told me that the rotation rate sensor was broken and he showed me the diagnostic results. It is about $500 and located under the driver seat. He also told me that he charges $750 for replacement. I didn't want him to fix it because of the price.
Than I started to looking for that sensor, however, it was very expensive everywhere. I also asked my cousin who lives in Germany. It is more expensive than here in Germany. Finally, I found a used one on Bavarian. It is $150 there but used, however they give 6 months warranty.
After I replaced the sensor problem solved. But I would like to give you the steps that I followed to replace the rotation rate sensor.
Here is some DIY for the following steps (check out the PDF files on the forum) however you don't even need them, just follow the steps.
1- Remove the driver seat (check out the attachment)
In this step you don't need to release seatbelt screw, just take off the seat and put somewhere near outside of the car, seatbelt extends.
The tricky part is, you need to disconnect the battery power before you disconnect the socket underneath the seat. Otherwise, airbag light comes up and you CANNOT RESET it with ODBII reader. Only dealer or special tools can reset the SRS airbag system. Also, you don't need to remove the head restraint too. The door is large enough for removing the seat and the seat is not heavy.
Don't forget to pick up the quarters and dimes ***61514; it is a very good opportunity to clean the carpet too.
2- Remove panel for pedals which is under the stairwell, the black cover. You don't need to refer anything as in the PDF file, there are three screws and some clips.
3- Remove front entrance cover strip, this is very easy too, use a screw drivers, there are four clips under that slip, it comes off very easy.
4- Remove the footwell which has just two screws.
5- The last three steps were for raising the carpet, so raise the carpet you will see the metal cover which covers the rotation rate or yaw sensor.
Removing it could look impossible because of the bolts which are at the bottom. It is easy the take off the top ones. However, you don't need to unscrew that bolts, I mean remove the two at the top but for the one at the bottom just take the bolt with its silver thing (I am sorry I don't know what it is) which connects the whole thing to the car's body. Then remove the bolts and plug back the silver colored metal stuff. This is kind of confusing sorry for broken English, but if you came until this step I am sure you're gonna find a way to take of the sensor.
Then, install the new one. No calibration or settings necessary. Install back everything; you can connect the battery after you connect the cable under the driver seat. Once more, if you don't disconnect you got to see the dealer and they charge at least $65.
I have been driving this car with this DSC problem since I bought it. And it drives very changed after I fixed the DSC system. Turns become very comfortable, I don't afraid if the car skids when I take the sharp turns with 50-60 miles speed.
One more thing, the rotation rate sensor is a sensitive part, do not drop it.
Good luck…