Yellow DSC light and yellow Brake fluid level light

2005 E46 318CI

So I only noticed this today, the yellow DSC light and the yellow brake fluid warning lights came on together (along with a short warning beep) and stayed on.

I drove to the local tesco carpark where I could pull in and check the brake fluid level, the level was fine, almost at maximum.

I turned off the the ignition, took the key out and waited about 30secs then started the car and the lights were off.

I then had to drive to Dublin from wexford, about halfway the lights came on again.

pressing the DSC button on did nothing.

Later today i was in the car for a while , waiting on someone (about 30 mins) I did the ignition thing again and the lights went out but after about 20 mins they came back on again.

I really hope this is just a faulty sensor or something ?

I read one thread where an american guy said he had the exact same problem and his garage wanted to charge him around $1,500 for a new DSC unit, but it turn out to be something else ( I can't for the life of me find that thread now as I was looking at it on the phone earlier)

You need to get the car scanned.

thanks, i'f i can't find anyone with the gear to do it for me , do you have any idea how much a garage would charge to do this ?

Have had this happen twice on my E46 over the years.

It could be brake pressure sensors, steering angle sensor, wheel speed sensors etc etc.

can be cheap enough, to several hundred euro

ok thanks,

and when the yellow DSC light comes onis the DSC really off ? or is it just a fault ? should i drive with caution ?

If the light is on the DSC is not working. I wouldn't panic too much, you'd want to really be hammering it around before it would be a dangerous. If the light is on one minute and off another its most likely a wheel speed sensor or something get it plugged in and you'll know.

Bump.

Ok I just scanned the car with my c310 bmw scanner

Here are the fault codes on the brakes

5E21 - pressure sensor 2
5E24 - pressure sensors
5E5D - level sensor, brake fluid
5E20 - pressure sensor 1


Is this saying I have three sensors to replace? Big job?

There are 2 pressure sensors as far as i know...i think maybe about €150 a piece plus fitting. Someone else might confirm.

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Originally Posted by Don B

There are 2 pressure sensors as far as i know...i think maybe about €150 a piece plus fitting. Someone else might confirm.

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really? f**k my life :(

anyone got a link where i can buy them online? mister-auto doesn't have them

see the results here:

http://www.ebay.ie/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR0.TRC0.H0.Xbmw+e46+d sc+sensor.TRS0&_nkw=bmw+e46+dsc+sensor&ghostText=&_sacat=0

any guidance as to which one i need?

Go on to bmwfans.info and look up your car (or type in last 7 digits of the vin) and look up the part numbers for the pressure sensors.

ok cheers, you really are being quite helpful to this n00b.

according to that site, the part no. i need is: 34521164458

http://bmwfans.info/parts-catalog/E46-Coupe/Europe/318Ci-N46/R-N/jan2005/browse/brakes/brake_master_cylinder_dsc/#1164458_2

is that right ? and I need two of the basterds?

Its No.2 in that diagram, just check the underside of the master cylinder, if your car is a late model it will have two of those sensors. Both are the same part number.

Its not a huge job just a bit fiddly.

Ok here's a weird thing.

yesterday before setting out on a longish journey I checked all my tyre pressures as I had a slow puncture in the rear driver's side.

I left the engine running whilst inflating each tyre to the correct 34psi

when I started the task, the yellow DSC and brake fluid level lights were on.

when I had finished all tyres, I got back in the driver's seat only to notice that the light had gone out.

I drove for 100KM (maybe a little less) and the lights came back on. They stayed on.

Later that day I went to my local tyre place as one of my tyres needed replacing for the NCT, while I was there I got him to fix the slow puncture in the other one.

The lights were still on at this stage.

after fixing both tyres, i drove to the nearest petrol station to chck pressures.

they were bit off after yer man was at them , so in put back in the correct 34psi

when i got back in the driver's seat again, i had noticed the lights were out.

coincidence ? ?????????

they've stayed out so far but I have only done about half the distance I did yesterday when they came on

Odd, does anyone know if the E46 has tyre pressure monitoring available as an option? Could this be it?

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Originally Posted by John_D

Odd, does anyone know if the E46 has tyre pressure monitoring available as an option? Could this be it?

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yes my one has a TPM button and the TPM light goes off when the tyre pressure gets low.

I don't have the solid valves on my tyres I have the regular ones so someone told me that my car measures differences in wheel speed or something and that's how it knows when a tyre goes below the recommended PSI.

This was a pain when I first got the car as I didn't know that one tyre had a slow puncture and the TPM light came on and i didn't know how to reset it.

Had this kind of problem 3 years ago. DSC lights lighting up like Christmas tree every 30 mins.Had it scanned and it was the dsc pressure sensor. It was replaced and codes were cleared. Bought 2 sensors and was told that only one was needed.

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Originally Posted by johnwayne

Had this kind of problem 3 years ago. DSC lights lighting up like Christmas tree every 30 mins.Had it scanned and it was the dsc pressure sensor. It was replaced and codes were cleared. Bought 2 sensors and was told that only one was needed.

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mine's a bit more random then every 30 mins, and the brake fluid light always comes on with it.

prices for those pressure sensors are crazy in Ireland, up to around €150 each!

can get them from china for around $45USD, so i might as well try that first

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Originally Posted by discopig

Quote:

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Originally Posted by johnwayne

Had this kind of problem 3 years ago. DSC lights lighting up like Christmas tree every 30 mins.Had it scanned and it was the dsc pressure sensor. It was replaced and codes were cleared. Bought 2 sensors and was told that only one was needed.

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mine's a bit more random then every 30 mins, and the brake fluid light always comes on with it.

prices for those pressure sensors are crazy in Ireland, up to around €150 each!

can get them from china for around $45USD, so i might as well try that first

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You might as well buy 4 of them Chinese ones, you'll be replacing them that many times compared to a genuine one!
On a more serious note you should get a proper diagnostic test done on the car before you buy anything.

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Originally Posted by rebel.ranter

You might as well buy 4 of them Chinese ones, you'll be replacing them that many times compared to a genuine one!
On a more serious note you should get a proper diagnostic test done on the car before you buy anything.

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cheers, yeah I feel that may be the case,

I've already read the codes with my scanner, (i have another thread with them here somewhere, can't search right now)

but yeah, it says brake pressure sensors

I've had a similar issue and the dsc came on due to low tyre pressure (slow puncture) , it also caused the abs light to ping on.If i were you I'd put some mileage under you as long as the tyres are holding pressure and the lights stay out.

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Originally Posted by Korsam

I've had a similar issue and the dsc came on due to low tyre pressure (slow puncture) , it also caused the abs light to ping on.If i were you I'd put some mileage under you as long as the tyres are holding pressure and the lights stay out.

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Thanks, I'd say I've done over 1,000 km now since it started. Tyre pressures are all ok and holding at 34psi , I check them each time before a long journey

Quote:

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Originally Posted by discopig

Quote:

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Originally Posted by Korsam

I've had a similar issue and the dsc came on due to low tyre pressure (slow puncture) , it also caused the abs light to ping on.If i were you I'd put some mileage under you as long as the tyres are holding pressure and the lights stay out.

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Thanks, I'd say I've done over 1,000 km now since it started. Tyre pressures are all ok and holding at 34psi , I check them each time before a long journey

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And still no lights ?

Quote:

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Originally Posted by Korsam

Quote:

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Originally Posted by discopig

Quote:

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Originally Posted by Korsam

I've had a similar issue and the dsc came on due to low tyre pressure (slow puncture) , it also caused the abs light to ping on.If i were you I'd put some mileage under you as long as the tyres are holding pressure and the lights stay out.

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Thanks, I'd say I've done over 1,000 km now since it started. Tyre pressures are all ok and holding at 34psi , I check them each time before a long journey

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And still no lights ?

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No sorry, I meant I've had the lights almost always on for the last 1000km

[quote=michael320]
Its No.2 in that diagram, just check the underside of the master cylinder, if your car is a late model it will have two of those sensors. Both are the same part number.

Its not a huge job just a bit fiddly.
[/quote

Hi, I have a BMW 316i E90 N43 with exact same problem and 5E20 code. i cant seen to find the sensor part though on bmwfan.info, is my a full unit change or can i get sensors. Any help is greatly appreciated.thx