CEL blinking, RPM stuck at 1000, high system voltage

[mckazok]

Hi Everyone,

I have a 2011 535i with ~110k running MHD stage 1
Car has been sitting about a week, started fine but I could feel minor vibrations at idle which cleared out once engine reached operating temp. Drove it about half an hour then parked for 4 hours. On the way back, while cruising at steady speed, CEL started to blink, and cluster got stuck at 1000rpm, speedometer was still working.

I pulled over, read the codes with generic obd reader which showed nothing. Then remebered I had wireless mhd programmer with me. Read the codes again and got these 4:
120208 Charge pressure too high
120308 Charge pressure too low
120408 charge pressure control switch-off
213301 power managememt: central over voltage

Cleared the codes in MHD app, restarted the car. This time CEL started to blink immediately, but there were no codes per mhd.

While CEL was still flahing, I just took the car on highway and drove home. Absolutely no issues, but RPM needle was showing a constant 1000 no matter the engine speed.
Unlocked cluster, it also reads exactly 1000rpms.

About the over voltage code, radar detector was measuring 15v all the time. I know it normally fluctuates all the time, from as low as 13.5v to close to 15v depending on engine load but never a contstant 15v, so that was new.

By the way, couples weeks ago I changed boost control solenoid, and all related drivability issues went away but I didn't clear the codes, so those 120xxx codes might just be old stuff.

About an hour after I parked and let the engine cool down while doing research for those sypthoms, went back and restarted the car, no CEL, no funny running, no codes stored. Go figure.

Any ideas what might have happened?

[mckazok]

Hello again,

I found the "issue" on another forum. Someone kindly reminded me having MHD installed, and its map switching function through BC button on turn signal stalk, which is what did that day; I reset consumption on the cluster.