I have been having a couple of issues with my Mini (Euro spec Mini One 1.4 95hp non-turbo Prince N12 engine)
When turning it on first thing in the morning, the car starts at high rpms (1.5k). The rpms only drop to abuot 750 after quite a long time. Once they do, the idle is somewhat erratic, especially if the car has been just turned on. The idle sometimes is all over the place when the engine is cold and it causes the car to stall when, for example, approaching a light or an intersection. Start & Stop does not work and the car is slow as hell, especially at low rpms.
Two days ago i unplugged the map sensor. The car threw a check engine light, but it drove PERFECTLY. The S&S obviously did not work, but I had no problems at all with idling. I then proceeded to buy another map sensor, swapped the old one, put in the new one and noticed in disbelief that the car started acting as it did before. If I unplug the sensor, the problems seem to solve themselves.
I have also replaced both vanos solenoids and cam position sensors. The timing chain has also been done no more than two months ago, fresh oil change.
If I scan the codes (with a generic reader), P1105 appears, "Dual alternator upper fault" it says... I also have a 2B15 code.
Could the alternator really be the cause of all these issues? Voltage appears to be fine (ignition on: 12.6 V, engine on: 14.2 V, engine + accessories on: 14.05) but it is slightly whiny.
Is it possible I had to do a vanos adjustement after having changed the solenoids?
My Mini does not have a MAF sensor, euro spec ones tend not to have it.
Throttle body is squeaky clean and appears to work fine, MAP sensor is, once again, brand new.
My engine, it being a non-turbo, does not have a HPFP either.
I have no clue what to check anymore, about to smash the car against a wall.
Thanks to whoever will read this thread!

 

Did the engine have this problem before the timing chain replacement?

No VANOS adjustment after changing the VANOS solenoids. Were the VANOS sprockets checked during the timing chain replacement?

 

Yep, I've had the car for over two years now and this issues has always been there unfortunately. Replacing the timing chain made no difference (I changed it for a different reason though, it was noisy on startup)

To be fair, I have no idea if they were checked or not, I suppose they weren't. I didn't really have the tools do perform a timing chain job by myself.

 

I looked up your code in Mitchell1. The P1105 and the hex 2B15 are the same thing; see clip below (OEM testing). I pulled up the 1.4L and the 1.6L N12 engines and the intake manifold is the same, but the air inlet is different. The 1.6L had a MAF sensor, but the 1.4L doesn't.

The fault you have relates to this part:

https://www.turnermotorsport.com/p-4...uine-bmw-part/

The MAP is located here: (Item 9) It's on the lower portion of the manifold. Is that the sensor you changed?


Does your intake look like this?







This is from Mitchell1.





From what I can tell from the Mitchell1 schematic (wires going into the DME have no text indicating what they are for). This sensor has four wires; it's a combination sensor (pressure and temperature). For the pressure part of the sensor, one wire is power (probably 5 volts DC) from the DME, another wire is the ground circuit, and the 3d wire is the signal going back to the DME that is proportional to the pressure in the intake manifold. In MAP controlled (speed density engines) that signal is critical to proper fuel scheduling. However, your code indicates the voltage is high. Meaning, that the DME sees that the voltage is above the pre-determined threshold. If you've changed the correct sensor, and there's no change, it's possible you have a ground fault. Without a ground for the circuit, the voltage can't drop. You need to take the car to someone with the proper diagnostic tools and training to help isolate the cause of the fault code.

 

First of all, thank you a lot for the very thorough answer

That is, indeed, the sensor I replaced and yes, that is my engine bay.

I've brought the car to a Mini specialist today, hope he will find a solution.

Thanks again for the help, I'll keep the forum post updated in case anyone else happens to need this in the future.

 

Have you already resolved the problem? I have exactly the same symptoms

 

Thank you for exposing the issue, I am in the same situation, I changed the same sensor and the problem persists. I hope you can fix it and share the info. Thank you in advance.

 

For code 2B15, these are some items that may be worth looking into, depending on your ECU variant.

 

On my case was a O2 sensor, bank 1 specifically. Still waiting for your to resolve.