ABS, DSC, Brake Light

Hi,

Although I have been reading a lot from this forum, this will be my first post.

I recently bought a 00 323i. This is the third one I have. (I had to sell others because of relocation, etc.). Although currently it has more than 161K miles, it runs great. I put more than 4K miles on it so far.

Here is the problem: There was a freezing rain in my area 2 weeks ago. The car was running fine that day. Two days later when I start the car in morning (the first start up after the freezing rain), yellow ABS, DSC lights and red brake lights pops-up in the dash. If I drive the car for 10 minutes, then shut it off for a minute and restart, first the red brake light disappears then the ABS and DSC. Then I don't see those lights throughout the day. After reading numerous forums, first, I changed the battery. However, it did not solve the problem. When the car is sitting (24 hours) I read 12.67V from the battery. When the car is running it is around 14.03V, when the high beam and heater is on, it is around 13.87V. Also, since those lights pop-up when the ignition turned to ON position (not cranked), and do not disappear by themselves, I think the problem is not the alternator as well.

I have read about ABS speed sensor problems. Do you guys still think my symptoms can be because of those sensors, even though if I only see those lights in cold starts?

Any help appreciated.
Thanks.

try topping off your brake fluid. low brake fluid tends to set those light off.

Thanks for the quick response. However, my brake fluid is full. The red light is for the hand-brake.

Originally Posted by e36-2.0

try topping off your brake fluid. low brake fluid tends to set those light off.

its your rear driver side speed sensor 100%
The exact same thing happen to me...
the lights would turn off after driving the car for a little if i shut it off and then back on.

first try to clean the sensor as they are very expensive..
if that doesn't work just replace it..

Thank you for the response. Do you know why it is the driver side? or is there a "functional" difference between the left and right rear sensors?

Originally Posted by Another BM

its your rear driver side speed sensor 100%
The exact same thing happen to me...
the lights would turn off after driving the car for a little if i shut it off and then back on.

first try to clean the sensor as they are very expensive..
if that doesn't work just replace it..

I got the ABS/ DSC/ Brake lit up and it was my passenger rear speed sensor. If you want to be 100% sure you can get your DSC codes read for around $100. The codes identify the wheel. You can check the speed sensors in all your wheels, start at the rear. It's held by one torx bolt and prys out. If there is one that is scuffed with maybe some brass visible under the black plastic, probably that is the speed sensor the Dsc diagnostics was flagged.

Originally Posted by xi_ter

I got the ABS/ DSC/ Brake lit up and it was my passenger rear speed sensor. If you want to be 100% sure you can get your DSC codes read for around $100. The codes identify the wheel. You can check the speed sensors in all your wheels, start at the rear. It's held by one torx bolt and prys out. If there is one that is scuffed with maybe some brass visible under the black plastic, probably that is the speed sensor the Dsc diagnostics was flagged.

I thought there isnt any speed sensors in the front.. Is there?

Originally Posted by G-Hots

I thought there isnt any speed sensors in the front.. Is there?

They are needed on all wheels for the ABS at least on the xi. I pulled all 4 of my speed sensors out to clean and inspect them.

Wow how many times are you people going to tell them the wheel speed sensor fixes it. There are so many things that can cause the abs and Dsc lights to go on. get the codes read before you put random parts on your car.


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Originally Posted by snowborder142190

Wow how many times are you people going to tell them the wheel speed sensor fixes it. There are so many things that can cause the abs and Dsc lights to go on. get the codes read before you put random parts on your car.


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OMFG thank you!!!!! Finally someone smart.

OP and everyone else, please read this damn thread here:

http://forum.e46fanatics.com/showthr...648&highlight=

Originally Posted by e36-2.0

try topping off your brake fluid. low brake fluid tends to set those light off.

Try having the brake fluid flushed. The fluid is not supposed to have any water in it, but it absorbs water over time. It doesn't seem as if the brake fluid should freeze at your house, but I don't know what your weather has been.

The red brake light is telling you there is a problem with the braking system, typically this is a problem with the fluid. If the brake system is reporting problems, the ABS and DSC are not going to work, and the lights to these systems will be turned on to inform you the systems are offline.

search!

Thank you for the all comments. Since the closest dealer was more than 50 miles away, I read the codes with INPA.

The error codes for ASC/DSC is attached as image. I am a little bit unsure about the codes. Therefore, please correct me if I am wrong. Do I need to change front left speed sensor and Steering angle sensor? The left rear sensor is also listed in the error list but the error frequency is shown as 0. I guess that sensor is okay!?

Also during this week my speedometer worked on and off. Do you think do I need to look other modules as well?

Thank you for your input.

Originally Posted by TrickTizzle

search!

Originally Posted by penet05

Thank you for the all comments. Since the closest dealer was more than 50 miles away, I read the codes with INPA.

The error codes for ASC/DSC is attached as image. I am a little bit unsure about the codes. Therefore, please correct me if I am wrong. Do I need to change front left speed sensor and Steering angle sensor? The left rear sensor is also listed in the error list but the error frequency is shown as 0. I guess that sensor is okay!?

Also during this week my speedometer worked on and off. Do you think do I need to look other modules as well?

Thank you for your input.

Clear the codes and drive the car and see which ones reproduce.
You can also see the value of the sensors as you move the steering or as the car moves...Which ever one that isn't throwing a good number is bad.
Also, if your speedo didn't work then most likely it was your rear wheel speed sensor that went out.

It looks like the errors that happened 254 times are the front left sensor and the steering angle sensor. The rear sensor had a frequency of 0. Replace the front left sensor first and search for steering angle sensor DIYs.

Yeah , WSS will trigger all those lights , in bad cases even the speedo will stop working (i had a ASC fuse blown and got no speedo)

As xi_ter said change WSS and look for steering angle sensor diy

Check your fuses and also replace the right rear Speed Sensor...

As TrickTizzle said, I reset the codes with the ignition on and then read the codes seconds later, only the rear left wheel speed sensor error pops-up with the frequency of 0. Then I drove the car for half of a mile while live-tracking the speed sensors, the left rear sensor was intermittently showing data. After I stop, I checked the error codes one more time, and it was again that same sensor. Therefore, I ordered a rear wheel speed sensor, hoping that it will solve the problem. Also, tomorrow I'll drive a little bit more to see if other codes pops-up.

Since my speedo works half of the time, I don't think it is related with fuses. However, I will keep watching for the front left sensor and steering angle sensor error codes.

Hope you get it all cleared up my friend. Those errors show up on me every once in a while randomly, and I can't seem to exactly pinpoint the problem yet.. Well I hope there's no problem.. Just a glitch hopefully..

Originally Posted by Black_BMW

Hope you get it all cleared up my friend. Those errors show up on me every once in a while randomly, and I can't seem to exactly pinpoint the problem yet.. Well I hope there's no problem.. Just a glitch hopefully..

Clean your impulse wheels(dunno the english name for it), it usualy gets dirty and sometimes causes intermittent problems.

As i've said before :
ABS/xSC/BRAKE lights coming on while driving are in 95% of the cases WSS , unless they've been replaced earlier then you should replace them.
ABS/xSC/BRAKE lights coming on after loosing traction is nothing to worry about , the system will reset itsellf in time or can be done yourself(steering angle sensor)
ABS/xSC/BRAKE lights coming on after DIY'ing the engine is almost always the throttle control being unplugged.