DSC Errors: Yellow DSC and Brake Light

[elrichmeister]

So my M3 has a Yellow DSC and Brake light. I got this error about 7 months ago, i was able to clear with INPA then returned in early October. So i cleared it again, then i popped again later in October, now its popping up often.

So now i do need to fix this issue. I scanned with INPA and it seems like brake pressure sensor 1 has a problem. When the car is cold the offset for brake circuit 1 was 7 in the red, when I turned on the it slowly creeped back down to 3.48 in the green. So I definitely seems to be an issue with what i hope is the sensor and not DSC unit.

I looked in the brake fluid reservoir and it does look a bit dingy, last time i had brake fluid flushed was 6/22 so little over 2 years ago, maybe i just need to flush the brake fluid?
Which is brake pressure sensor 1? Nearest to firewall, or away from firewall?
Another question offset steering angle is in the red, from INPA live data, is that something to worry about? steering wheel seems straight.


couple of screen shots: First Screen Shot was cold, engine not running, 2nd and 3rd was engine running it eventually settled at about 3.48

Also a quick video pressing the brake pedal with engine on

https://www.youtube.com/watch?v=Xwtud6cCocU

INPA Scan

E R R O R M E M O R Y
---------------------------------------
Date: 28.10.2024 20:12:59
ECU: DSC_MK60
JobStatus: OKAY
Variant: DSC_MK60
-------------------------------------------------------------
RESULT: 1 error in error memory !
-------------------------------------------------------------
5E20 Druck Sensor 1 elektrisch defekt

Error counter: 6
Logistic counter: 40

  Mileage                              271590 km
  Fahrzeuggeschwindigkeit            2.00 km/h
  Bremslichtschalter                         1.00 0/1
  Bremsfluessigkeitsschalter          0.00 0/1
  ASC/DSC_aktiv (Tasterfunktion)  1.00 0/1
  Bremsdruck erkannt                     0.00 0/1
  ABS-Regelung                              0.00 0/1
  ASC-Regelung (BMR)                  0.00 0/1
  ASC-Regelung (AMR)                  0.00 0/1
  GMR-Regelung (GMR)                  0.00 0/1
  GMR-Regelung (MMR)                  0.00 0/1
  CBC-Regelung                         0.00 0/1
  MSR-Regelung                         0.00 0/1
  TDR-Regelung                          0.00 0/1
  SDR-Regelung                         0.00 0/1
  DBC-Regelung                         0.00 0/1
  RTA aktiv                             1.00 0/1
  Run-Up Mode                           0.00 0/1
  kein passendes Fehlersymptom
  Testbedingungen erfuellt
  Fehler momentan vorhanden und bereits gespeichert
  Fehler wuerde das Aufleuchten einer Warnlampe verursachen

Error code: 5E 20 E0 06 28 6A 17 02 09 00 04

=============================================================

[heinzboehmer]

Start with a flush. If it comes back then yeah, the likely culprit is the sensor.

Fortunately the sensors are expensive and extremely annoying to swap out

[bmwfnatic]

There’s 2 same sensors, if you do them, do both.
You can get in there with an open ended wrench, not exactly fun but it’s ok.
I’ve personally had good luck with aftermarket ones from eBay here, much cheaper.

[liam821]

Fortunately the sensors are expensive and extremely annoying to swap out

You can also find those two sensors on any e46 2002+ with an MK60 at your local pick'n'pull and spend a few bucks.

[elrichmeister]

Thanks for the suggestions, will update this post when I get this issue resolved.