[SSonics]

Originally Posted by mehmetx

By repeatable, i mean braking occurs whenever i turn on wipers. Furthermore, when wipers are on and the speed is above 80km/h, auto braking occurs every 20-25 seconds.

When the car brakes itself, it doesnt allow me to accelerate for that 2-3 seconds to compensate the braking even tough i hit the acceleration pedal.

After that 2-3 seconds of auto brake, it frees up and i can accelerate again

I have the same exact issue but mine occurs only on heavy rain. Doesn't matter if the auto wiper is on or not. Didnt really look into it before but now its gone

[mehmetx]

I took my car to the technical service. The brake ststem has been checked and nothing is wrong. Also the software has been updated. The problem still persists.

Also we disabled the dsc by pressing the button which is above the mode selection button. The problem still persists. Does it mean that dsc is not the reason?

The technical service noticed that headlights turn on when the wipers are on and it turns off when the wipers are off. headlight switch is positioned as Auto. This made him think about rain/light sensor problem. The time of day was such that headlights arent supposed to turn on. We checked the car history and found out that rain/light sensor didnt change when the front windshield was changed. He said rain/light sensor glue should have been changed when the windshield is changed.

He also said that auto brake occurs like cruise control brake in terms of intensity. And it cant accelerate as if speed limiter is applied via lim button on the steering wheel.

We are gonna replace rain/light sensor and get rid of cruise control buttons and check if the issue is solved

[COKen]

Originally Posted by mehmetx

He also said that auto brake occurs like cruise control brake in terms of intensity. And it cant accelerate as if speed limiter is applied via lim button on the steering wheel.

Even if the CC is applying the brakes, you can still press the accelerator to over ride the CC and your car will speed up. That doesn't seem to be what you are describing as your issue.

[mehmetx]

Originally Posted by COKen

Even if the CC is applying the brakes, you can still press the accelerator to over ride the CC and your car will speed up. That doesn't seem to be what you are describing as your issue.

Maybe both limiter and cruise control malfunction. Cruise control is responsible for braking and limiter is responsible for not being able to accelerate. Even though i push the accelerator till end, turbo delay + gear shift time may be larger than auto brake duration.

I know this has very small possiblity but just a hope

[pshovest]

Check calibration or replace the brake pressure sensor. If sensor is out of calibration the system may be applying 50 bar pressure rather than the 3 bar required thereby braking the car excessively. You should be able to see the pressure with live data in ISTA while you drive.

[mehmetx]

cruise control disaasembled from steering wheel, non cruise version limiter button assembled
rain/light sensor removed and changed with new one

Problem still persists

Next step is dsc unit change, will update here as well

[PK2348]

Are you the original owner? If not, is there a way in your country to get access to service records?

[mehmetx]

Originally Posted by PK2348

Are you the original owner? If not, is there a way in your country to get access to service records?

Yes i can reach service records. What kind of information do we need ?

[BBri89]

It could be normal brakes, and an abnormal brake-drying function, such as too much pressure applied.

It could be a normally-functioning brake drying function, but with abnormal brakes, so the pressure applied is normal, but a slightly sticking caliper is then applied harder causing deceleration.


If it is ONLY linked to wiper blades, then it HAS to be related to the brake-drying function, even if that itself is behaving correctly and the true cause is something else.

[HighlandPete]

Before throwing parts at the problem, live data would be the wisest first move.

As has been suggested, (by pshovest), try and get the pressure readings during the fault sequence.

[mehmetx]

dsc unit is changed and the problem is solved.

Waiting for new dsc to arrive.

[emrecicek]

Originally Posted by mehmetx

Hello

My car is F30 2014 3.20ied with 1.6 liter 4 cyclinders engine.

My car applies brake when the windshield wipers are on while moving with speeds above 80km/h. It makes me lose 10/15 km/h speed. The braking is not harsh and the duration of the braking is 2-3 seconds. Cruise control on or off doesnt make any difference. The problem is repeatable.


I have searched the forums and some people point it to brake drying feature. The solution is suggested as dsc/abs ecu change, brake hydrolics change, abs hydro pump change or disabling it via software modification. None of these solutions is certain.

Does my car have brake drying feature?

How can this problem solved?

Please dont say dsc/ abs ecu needs to be changed

None of the technical services in my country has an idea. Im feeling very desperate.

Note: My car has rain / light sensor

Hi friends
I had the same problem, exactly as you described. I disabled it by coding and the problem was completely resolved. Pressure range adjustment can also be made in the brake drying system. but since I don't know the parameter values, I chose to turn it off completely. the code should be like this Enable dry braking
''DSC 3000 c_funktion_trockenbremsen_aktiv_1''

[njdangelo]

Brakes are important and yours aren't working well. You should absolutely take this into a bmw dealer or specialist to get it taken care of properly and quickly.

[Boklsg]

Originally Posted by emrecicek

Hi friends
I had the same problem, exactly as you described. I disabled it by coding and the problem was completely resolved. Pressure range adjustment can also be made in the brake drying system. but since I don't know the parameter values, I chose to turn it off completely. the code should be like this Enable dry braking
''DSC 3000 c_funktion_trockenbremsen_aktiv_1''

Are you able to show how you disable it? I am having the same problem. It's very dangerous.

[chrisjm]

I have the same issue with my car and its looking like I will have to the dsc unit replaced to fix it. All other options have been looked at inc brake fluids, brakes and calipers.

Just a note of caution - disabling the DSC unit / dry braking (aside from for testing purposes) may void your insurance, warranty etc...

[HighlandPete]

Originally Posted by chrisjm

I have the same issue with my car and its looking like I will have to the dsc unit replaced to fix it. All other options have been looked at inc brake fluids, brakes and calipers.

Just a note of caution - disabling the DSC unit / dry braking (aside from for testing purposes) may void your insurance, warranty etc...

I'd also be cautious of coding/disabling anything to do with a problem DSC unit. Something else could also be wrong with it, not evident to the driver until an emergency.

[harmeetsaimbhi]

Hi !

Were you able to resolve this automatic breaking issue after replacing DSC unit ? I'm having the same issue of ABS/DSC unit applying breaks in rain when rain sensor is on at around 90-100kmph which brings the speed down to 80kmph. And this is happening after short intervals. The worst part is that there are no error logs or codes getting logged into the system. Looking forward to hear back on this thread.

thanks,

[HighlandPete]

Originally Posted by harmeetsaimbhi

Were you able to resolve this automatic breaking issue after replacing DSC unit ? I'm having the same issue of ABS/DSC unit applying breaks in rain when rain sensor is on at around 90-100kmph which brings the speed down to 80kmph. And this is happening after short intervals. The worst part is that there are no error logs or codes getting logged into the system. Looking forward to hear back on this thread.

According to this post, OP is saying yes.

Originally Posted by mehmetx

dsc unit is changed and the problem is solved.

Waiting for new dsc to arrive.

[M4gn3tic]

mehmetx HighlandPete njdangelo

I have exactly the same problem. My car is 1.16ed 2014, does anyone know a more economical solution? Like a way to know for sure that the DSC module might be broken?

[pmfung]

I had the same issue for about 2 months ago. The wet brake wiping feature was overly active whenever the wipers were on at highway speeds. I would typically lose 5-10mph, every 90 sec or so... a little un-nerving.

More recently, the rear brakes were dragging and I could feel hesitation, so I couldn't ignore it anymore. In brief, I took separated the ABS module from the electronics board, ultrasonically cleaned the solenoids, blew air into the orifices, and reassembled. Wala. All good now.

[Sunny320i]

Originally Posted by pmfung

I had the same issue for about 2 months ago. The wet brake wiping feature was overly active whenever the wipers were on at highway speeds. I would typically lose 5-10mph, every 90 sec or so... a little un-nerving.

More recently, the rear brakes were dragging and I could feel hesitation, so I couldn't ignore it anymore. In brief, I took separated the ABS module from the electronics board, ultrasonically cleaned the solenoids, blew air into the orifices, and reassembled. Wala. All good now.

Hi there, I have the exact same issue however instead of the rear brakes dragging it's the front brakes. Is your car still driving normally after doing what you did?

And I'm going to direct message you because I would really love to speak to you on the phone if possible to figure out how you did this.

Thank you!

[BWbimmer]

The brake drying mechanism applies to all 4 wheels. The isues do not necessarily only occur on the rear.