code 1215 Mass Airflow Sensor

[dbg1ok]

Ok i will try to keep it brief, but i really need some help on this one. Last Year i purchased a 1995 bmw 540i, slowly but surely i have been updating and fixing things on the car, last winter though it started idling really rough. It proceeded to do this the entire winter until the summer hit, when it stopped. I was like ok thats cool. I live in Tn and it is starting to get cold again and guess what, it starts idling rough again and the check engine light comes on once more. I just found out today how to read the codes using the stop 5 times method, and i got the code 1215 which is the Mass Airflow Sensor code. How can i fix this problem, or what are the problems most associated with this code. Thnx!!

[makaveli2k]

You can try cleaning the Maf, or if worse comes to worst. Change it.

Are you throwing any other codes? Have to stomp the pedal again 5 more times to retrieve another code.

[dbg1ok]

ohh ok, i will go try that.What would u use to clean?

[skylinergtr]

it needs another maf. Cleaning it wont really help. I tried cleaning mine when my car threw the code and it did nothing. I bought a used 540i maf off ebay for 50$. All good now.

[makaveli2k]

See if you can find this stuff.

http://www.crc-canada.ca/Default.aspx?tabid=235

I'm sure they have other Mass air flow sensor cleaners around though.

[dbg1ok]

ok so i did a little more stomping and i am throwing the codes 1221 and 1111...???

[bubba0966]

Unplug the MAF. Start the car. Does it idle better? If so the MAF needs replacing. If it idles the same you have a vacuum leak that's throwing the MAF code. I found out the spendy way that a MAF code can be a vac leak or a bad MAF.

[makaveli2k]

http://www.bmwe34.net/Wiki/tiki-inde...e=Engine+codes So does the weird idling start right when you start the car or does it start after you let it warm up a bit?

added new working link by shogun https://web.archive.org/web/20110101...e=Engine+codes

[dbg1ok]

Always after it warms up a bit.

[makaveli2k]

Always after it warms up a bit.

That's the o2 for sure then. Replace it. As for the Maf, try the test that one of the above posters said (disconnecting the connector) and see if things improve. I had a bad maf, but it didn't mess with my idle just more mid-low range rpms under moderate throttle.

[dbg1ok]

Ok so with everyone's help i have most certainly determined that something is up with the MAF...i am throwing that code and the 1sy oxygen sensor code.

After i found this out i unplugged the MAF and started the car. To my amazement the rough idle was gone, sat there for awhile just to make sure. then turned it off. Plugged the MAF back up and just like clockwork, that rough idle is back.

I think i am going to try the MAF cleaner if that doesnt work then i will get a new sensor.

[skylinergtr]

I had the exact same problem maybe a year ago. I replaced both o2 sensors with brand new bosch's. Replaced the maf with a used one. Car went from running like absolute crap to running great again. I had a maf code and o2 sensor #2 code. I dont suggest wasting money on that maf cleaning spray. I did it before i got a used maf and the can of maf cleaner was like 10$ when a used maf was 50$.

[E34tn]

I have this same rough idle fiasco going on myself. Occasionally idles real rough when i first start the car and the check engine light comes on until i put it in drive and take off. After its been driven and i park it, it idles as smooth as can be. It drives me crazy and i wish i could figure out what is causing it. I tried the stomp test and couldnt get it to work. So i dont know?

[dbg1ok]

when you stomp its gotta go all the way down. turn ignition on, stomp 5 times within 5 sec and the check engine light will start flashing. flashes correspond to the code

[E34tn]

when you stomp its gotta go all the way down. turn ignition on, stomp 5 times within 5 sec and the check engine light will start flashing. flashes correspond to the code

Yeah ive tried it several times and i just cant get it to do anything. I turn the key all the way without actually starting the car and stomp the gas pedal 5 times to the floor and i get nothing. The check engine light stays constant and never flashes.

[jehu]

Yeah ive tried it several times and i just cant get it to do anything. I turn the key all the way without actually starting the car and stomp the gas pedal 5 times to the floor and i get nothing. The check engine light stays constant and never flashes.

thread ressurection day

I recently had this happen and it was in fact the Throttle Position Sensor which reads when you depress the accelerator pedal.. bad sensor>no stomp test recognition. New TPS> Stomp test back.