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

David wrote:
>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
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.

bbeyer wrote:
> David wrote:
> >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
> 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.

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.

David wrote:
> bbeyer wrote:
>
>>David wrote:
>>
>>>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
>>
>>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.
>
>
> 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.
>

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.

--
-Fred W

David wrote:
>> >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
>[quoted text clipped - 29 lines]
>> check that code number at work tomorrow if i remember (i work at BMW) and try
>> to get back with some more ideas.
>
>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.
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.

--
Message posted via CarKB.com
http://www.carkb.com/Uwe/Forums.aspx/bmw/200609/1

> 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.
>
> --
> -Fred W

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!

David wrote:
>>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.
>>
>>--
>>-Fred W
>
>
> 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!
>

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

--
-Fred W