What does this code mean..?

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Hi all,

I have had my Z3 (M44) for a few weeks. I'm really happy with it except for the rough idle. There are no warning lights showing and when the revs are at about 1,000 it seems perfect however idling is erratic and it has stalled once or twice.

I had replaced the ICV but that didn't seem to cure the problem and after ordering a code reader off ebay, this evening I plugged it in to see what (if anything) it would report. The result was;

P0100 Pending. Mass or Volume Air Flow "A" Circuit.

Any ideas what this is indicating?

Thanks in advance for your wisdom.

 

[GazHyde]

P0100 Pending. Mass or Volume Air Flow "A" Circuit..

I'm sure one of the [USERGROUP=12]@M44 Massive[/USERGROUP] will be along soon, but I'd say it's going to point to the MAF sensor on the air intake.

It's possible to clean the MAF sensor (carefully) which may help, or you may need a replacement.

 

[upstream]

I'm sure one of the [USERGROUP=12][USERGROUP=12]@M44 Massive[/USERGROUP][/USERGROUP] will be along soon, but I'd say it's going to point to the MAF sensor on the air intake.

It's possible to clean the MAF sensor (carefully) which may help, or you may need a replacement.

Thanks. I had replaced the air intake boot recently as the one on there was duct taped together and had split but unfortunately this didn't make a difference. My understanding is that there are so many things that could cause an idle misfire that without reading the codes I could end up spending lots of money replacing perfectly good parts so hopefully at least I'm a little closer to sorting it out now ;-)

 

[GazHyde]

It's amazing how many faults get "diagnosed" without codes being read considering how easily available readers are now.

 

[hard top]

I would also say MAF but @zedonist will probably be along shortly and can tell you a lot more than I can.

 

[zedonist]

Description - P0100 - Mass air flow (MAF) sensor / volume air flow (VAF) sensor - circuit malfunction

Possible causes - Wiring, MAF / VAF sensor, ECM

It would suggest that one of the things in the air flow sensor circuit is malfunctioning, if you have cleared all air leaks, and this is the only code present, then if you wiring is not broken, i would fit a new MAF

 

[upstream]

Description - P0100 - Mass air flow (MAF) sensor / volume air flow (VAF) sensor - circuit malfunction

Possible causes - Wiring, MAF / VAF sensor, ECM

It would suggest that one of the things in the air flow sensor circuit is malfunctioning, if you have cleared all air leaks, and this is the only code present, then if you wiring is not broken, i would fit a new MAF

Hi,
From what I could tell the only air leak was the intake boot. This is also the only code that is showing. I did try disconnecting the MAF about a week ago and it didn't make any difference (just idling - I didn't try to drive it), but it did cause a light to show on the dashboard (It went away next time I plugged the MAF back in and restarted the car so I'm assuming that the wire is ok based on the fact that the light came on when I disconnected it and went out again when reconnected).

I also went to a menu on the reader called I/M Readiness. It had lots of things on there which didn't make sense to me. They were;

MIS FUE CCM CAT HCA EVA AIR ACR OZS HTR EGR

The MIS and ACR were both in a rectangular box and OZS HTR EGR were greyed out.

I'm not sure if this is indicative of anything.

 

[zedonist]

Items will be greyed out as there is no access to them from the reader, or they are not present on the car. Where are you located? I am sure a fellow M44 owner, including myself if local, could meet you, and let you try their MAF in your car.

 

[upstream]

Items will be greyed out as there is no access to them from the reader, or they are not present on the car. Where are you located? I am sure a fellow M44 owner, including myself if local, could meet you, and let you try their MAF in your car.

Hi,
I'm in Dudley - just North of Birmingham.

 

[zedonist]

Just as an aside, have you cleared the code on the car and then gone for a run in the car? The ECU does adapt to driving style and engine condition, giving it a prolonged run may remove any adaptations from when running with the air leak. I am also sure that disconnecting the battery for 30 minutes will remove any stored adaptations.

 

[zedonist]

I'm in cannock, let's meet up, drop me a pm

 

[zedonist]

 

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UPDATE...

Well guys - Courtesy of @zedonist my car is now running like a dream. I won't go into all of the details other than to say that this guy is a real gent - Not only did he give up part of his saturday morning to help me out but he did it two saturday's in a row!!

Can't thank you enough mate - as we used to say in Australia "You little ripper!"

PS... The downside to all this is that having seen how beautiful his car is, I'm quickly developing a shopping list which will probably not put me in the good books with the other half ;-)

 

[zedonist]

Thanks Mate,

Its what a forum is for, if i can help i will, glad its running sweet now.

 

[David Cullen]

hahaha good man Zed, great to see people willing to give up their time to help others

 

[Brian4]

Glad your are sorted now, and to zedonist for helping out.

 

[upstream]

Glad your are sorted now, and to zedonist for helping out.

Thanks to you also for pointing me in the direction of this forum

 

[oldcarman]

Glad to see the Zed got your zed up and running. Was hoping he'd swing by my place to take a peak at Trinity while he was in Canada but something about the 2500 mile trip threw him off. Guess he's not that willing to make the major sacrifice. lol JIM

 

[zedonist]

Jim if I could i would.......

 

[oldcarman]

Jim if I could i would.......

That way you would see that I do in fact own a Z3! I do have some pics but with so little time available away from the forum( you aren't alone Shelly) just haven't found the time to learn the process on how to file them for you.