Mass air flow warning: flow too high
Mass air flow warning: flow too high
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trebnamo

Original Poster:

55 posts

55 months

Monday 11th August
quotequote all
I have a 2015 M235i from new that has been trouble-free for the entire time I've owned it, but it threw me a surprise yesterday.

Driving 150+ miles in the hot weather and in very stop/start traffic for an hour or so on M40/M25, the car suddenly makes a clunk noise and afterwards starts being a bit rumbly under load. I'm almost home and I get an orange "Drivetrain" warning on the dashboard. Then a bigger warning "Possible to continue journey. Full performance not available. Have the problem checked by your Service Partner."

Get home, plug in OBD Bluetooth and get the fault code: "P00BD Powertrain - Mass or Volume Air flow A Circuit Flow Too High".

Has a piece of the infamous BMW plastic under the bonnet gone pop? I looked under the bonnet and I guess it could be any of this:



Nothing obviously damaged or loose. I'm reluctant to take it to a dealer in case the answer is "new engine sir". Any ideas how I can get a better idea of diagnosing what happened? It has to go from Surrey to North Wales in a fortnight so I'm concerned about it being match fit spin

bigdom

2,219 posts

162 months

Monday 11th August
quotequote all
It's highly unlikely to be the engine. I'd skip the dealer, and have a chat with a local specialst as they are more used to fixing older cars.

You mention Surrey, personally i use https://twgautomotive.co.uk/ in Camberley. They might not be close to you, so have a look at the directory at the top of the page.

trebnamo

Original Poster:

55 posts

55 months

Monday 11th August
quotequote all
Thanks for the recommendation and I think you're right about going to a specialist - I think I'm going to Birds as they are closer to me and they have had the car before, just gave them a call and they can fit me in next week. Will take it easy until then, and looks like I'll need to hire a car for Wales.

Coco2021

2 posts

1 month

Monday 25th August
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I have the exact same issue, did you manage to get any answers from the specialist?

kev b

2,755 posts

183 months

Monday 25th August
quotequote all
My guess - Intercooler hose split causing more air to pass through the MAF than the engine can use hence the code.

Coco2021

2 posts

1 month

Tuesday 26th August
quotequote all
My engine management light turned amber when I got the drive terrain warning. I have 2 codes P00BC which is air flow too low and P00BD which is air flow is too high. So im confused how it is both!? I have not noticed the car any different when driving.

I have a 2015 X3 Diesel. Im entirely new to this and don't trust mechanics frown