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CEL when touching the Brake Pedal (+ Code 2B4E / 2B2B)
Hello everyone!
I have a rather strange issue with my Mini R56. I live in Martinique and no one seems to find the problem... Almost a year ago, I had an engine warning light and loss of power. The ignition system of one of the cylinders was defective and... Well, it was fixed, and everything was fine after that.
I'll mention something, I'm not sure if it's important: One day, I helped jump-start a car (with jumper cables). At the time, nothing special happened, but after that, the "engine warning" light came back on... before going off. And it kept coming back on and off regularly, until it started coming on systematically...
So, I went to the garage where they read the codes 2B4E and 2B4B, and for them, it's the speed sensor that's faulty. I found an accelerator pedal on the Internet, it took 2 months to arrive (I live in Martinique), and... Nothing, the error persists.
Nevertheless, I tried to understand, and:
- The CEL (Check Engine Light) is systematically present at startup (except If i'm clearing the codes)
- The car is in LIMB mode (degraded engine)
- If I drive a bit, turn off the engine, and restart it, the engine light doesn't come back on... and it lights up the exact moment I touch the brake pedal.
- Sometimes, if the engine is warm, even braking doesn't bring the engine light back...
- Starting the car a few hours after driving it will bring the engine light back. If there is no CEL at startup, pressing the brake button will bring back the CEL.
Another detail: when stationary, when I take PedalE measurements (I'm not really sure what it is), when I press the accelerator pedal fully, it's at 40%, and when I release the pedal, it's at 7.1%. I'm not sure if these are normal values (and this is with both pedals). Also, if I press the brake pedal, the minimum value of the accelerator pedal goes up to 7.5%. It does this with both pedals (I bought the pedal second hand, it could also be defective, but it seems unlikely to me).
Today I changer the throttle pedal with a brand new, and the problem is still there :( !
Has anyone ever had this type of problem? It's been 6 months since I've been dealing with this, I don't even know if BMW in Martinique would be able to fix the problem, I'm losing hope (and it's my second Mini, the first one, an R53, I had to sell because no one could change the clutch for me).
Last edited by SuzuKube; Mar 19, 2024 at 05:27 AM.
Reason: False Code 2B4B is the good one !
2B4E is a throttle position sensor fault, but seems to be secondary.
Seems to me that the 2B2B code is the real culprit. That code is related to the throttle valve position sensor. Possible you’re getting a faulty reading from the throttle position sensor, and the DME is pulling those codes as a result.
Thank you for the answer ! Unfortnuately, i writed a false code, it's 2B4B and not 2B2B, it's also related to the Throttle :/ ! Perhaps I should replace the valve also ? I don't know :/ Strange it's when braking...
OK. If you go to that code website, here is the service plan for that code:
- Check wiring harness between accelerator pedal module and DME - Replace accelerator pedal module - Replace DME
You already replaced the pedal, and no change. If the wiring is good, you'll need to either replace or fix your DME. If it all started when you jumped another car, it is possible the DME was damaged.
OK. If you go to that code website, here is the service plan for that code:
- Check wiring harness between accelerator pedal module and DME - Replace accelerator pedal module - Replace DME
You already replaced the pedal, and no change. If the wiring is good, you'll need to either replace or fix your DME. If it all started when you jumped another car, it is possible the DME was damaged.
Thank you for your help. I checked some stuff, and now I know the problem occurs only if the Brake Pedal Censor is activated (I mean If i'm putting the brake pedal censor in a way he can't detect the pedal, everything is right).
I have also a melted left rear bulb I think it's something about the electricity - now I have to found what :/ Perhaps change the entire Rear light of the car, the wires. I'm not sure about damaged DME it worked very well without the Brake Pedal Censor ! Apparently it's used only for brake light ?
DME seems to be like a 2000€ reparation lol I think I will stay with limb mode, I can't afford my self this I have to buy my house before :( ! When I'm checking graph, it's as if as soon the Brake Light is on, it's causing an interference on the accelerator value, it's going from 7.5% to up to 8.6%. I think that is what is throwing the error, now I have to find a way to repair that. Perhaps it's just the Brake Censor to change ?
Last edited by SuzuKube; Mar 20, 2024 at 12:11 PM.
So the problem was... The ECU. I don't know why it failed. Perhaps the Jump Start of another car. Perhaps the Melted Bulb. Perhaps the NOX sonde that was HS. But It was the ECU, I had to replace it. A garage in Martinique (Autotech) have done it for me I had to buy a used one and replace it.
It cost me around 1000 € to replace all, but now it's running ok.
