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Code P1447 Service Engine Soon

I have a 2001 E46 325i with 32K miles. My Service Engine Soon light came on, and I stopped by Auto Zone where they put a code reader on it and it displayed code P1447. Searching around on the internet I found that this is apparently an incorrect flow to or from the evaporative canister, but the Auto Zone guy told me the code could vary some by manufacturer. I looked at all the lines to the canister, and they appear to be in good condition. Can a faulty gas cap affect the flow to the canister, or is there some valve that controls it that might be bad? The car runs perfectly, but I'd like to fix it rather than contribute to depleting the ozone layer. Incidentally, the existing gas cap is not connected to the car by the little rubber tube, leading me to think it was replaced once before, but it does appear to be a genuine BMW cap. Since I don't have a repair manual, I'm hoping someone out there can point me in the right direction, as I'm not very close to a dealer.

Thanks in advance for any help

Reply to
David
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are you sure it was a flow issue to the evap canister? the only fault i think that can set for the evap system would be a minor or major tank leak detected. this car has a system called DMTL which pressurizes the fuel tank and measures the speed of a reed switch which is connected to the pressurizing pump (are you with me?) the speed of the reed switch is measured, and the control unit knows that if the reed switch slows down, that the tank is sealed because its building pressure. if the switch is going faster, obviously, it knows that there is a leak. now this may not even be related to your problem. i think the other thing you may have is a bad secondary air system. there is an electric pump in the R/F under your hood that injects fresh air after start up. there is a valve to let the air into the exhaust which is controlled by vaccum. these vavles go bad frequently and throw a code for no secondary air flow. either that or the pump just stopped working and there is no air going in because of that. i'll check that code number at work tomorrow if i remember (i work at BMW) and try to get back with some more ideas.

Reply to
bbeyer

Thanks for the reply. I've looked some more on the internet, and found a mfg. specific code list for the BMW which describes the code as "Diagnostic Module Tank Leakage (DM-TL) Pump Too High During Switching." I see that the next code, P1448, is for the pump too low during switching, so now I'm confused. Is pump too high an indication of a leak? Either way, I guess I'm destined for a trip to the dealer. Thanks again for your help.

Reply to
David

Are you sure that this wasn't a loose gas cap? The cap is part of the evaporative recovery system which is also what the canister is involved in.

Before I spent any money at the dealership on diagnostics, I would tighten the gas cap, clear the codes, and see if it comes back.

Reply to
Fred W

yes, too high means a leak. i dont even know if i've seen the too low fault, because that would mean that the tank is sealed.

Reply to
bbeyer via CarKB.com

I called the dealer, and they said the light should go out on its own within a few days if it was the gas cap. It didn't, but I took your advice and I cleared the code, and so far it has not come back. Go figure. But I'm not complaining, Taking Fred's advice meant this repair was FREE!

Reply to
David

Best give it a little more time before you count your free victory... ;-)

Reply to
Fred W

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