Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help

Go Back   Pelican Parts Forums > BMW Forums > BMW Technical Forums > BMW 3-Series E46 (1999-2005)

LinkBack Thread Tools Rate Thread
Thread Post New Thread    Reply
Join Date: Mar 2021
Posts: 1
5E21 Pressure sensor 2 fault (Bifecta) but sensor replaced twice

Hello, I have a 2003 325 Ci Convertable (automatic, in UK) which has the bifecta issue (DSC+amber brake light warning). Plugging in a code reader lists "5E21 Pressure sensor 2". I have replaced this but the code was still present. 6 months later I have replaced the sensor again in case the first was a dud along with bleeding the brakes and cleaning the ends to the plug which goes into the sensor, but the error persists and as every guide and post I seem to find online says that replacing the sensor solves the problem (which in this case, it hasnt), I am a bit stuck on where to go next.

To give some extra background, 6 months ago, I also replaced pressure sensor 1 when I first replaced sensor 2 (late August) to be proactive, which then also triggered an error code, 5E20 (Pressure sensor 1) and upgraded the bifecta to a trifecta when the ABS light then came on, along with a handful of front wheel speed sensor faults for both front wheels. However this was solved by changing both front wheel speed sensors - once done and clearing the error codes, 5E20 and the wheel speed sensor codes have never came back and the ABS light has also stayed off. But the bifecta and 5E21 remains.

So to sum it up:

Bifecta issue present since early August
5E21 pressure sensor 2 fault is present
It reappears as soon as you clear the fault codes
The DSC and amber brake light are constantly on (they have not turned themselves back off after driving, nor is it an intermittant issue) and once you start driving, you hear a beep after a few meters
Pressure sensor 2 (one nearest to the windscreen) has been changed twice (once in late August and once yesterday) with two different sensors
Brakes have been bled. No brake fluid appears to be leaking.
Plug connectors have been cleaned.
Car itself appears to behave - certainly no brake issues etc and brakes feel ok
Trifecta appeared when pressure sensor 1 and 2 were first changed (late August) but was sorted by changing both front wheel sensors in January, also solving the 5e20 pressure sensor 1 problem - none of these codes have appeared since.

Looking around online appears to yield no answers beyond "Change Pressure sensor 2" as every case I find of doing this is able to solve the issue, which in this case has not. Could it be the rear wheel sensors also need changed, even though they are not producing an error code? (Given changing pressure sensor 1 then appeared to trigger the front wheel sensor issues).
Hopefully it is not the DSC unit itself - the fact that the trifecta issue has resolved makes me think it is ok.
If it is not the rear speed sensors, does anybody know what could be causing this issue or any other thoughts and areas to try?

Old 03-02-2021, 01:20 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)

Thread Tools
Rate This Thread
Rate This Thread:


All times are GMT -8. The time now is 12:14 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2020 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.