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Discussion Starter · #1 ·
Hello all, long time lurker and first(ish) time poster!

I drive a 2005 330xi.

So this past Sunday I spent about 2 hours replacing the lower intake boot (massive crack in it) as I was getting some nasty lean conditions. While I was in there I took out the ICV and cleaned it really good with some Carb Cleaner as this past Friday I got an ICV stuck closed error. I figured this error was most likely from the crack in the intake boot since it connects to the ICV, but I cleaned it anyways as it was pretty gunked up.

After doing the above work, I put everything back together, plugged everything in, and the car seemed to run better than it has in months. But when I checked my fuel trims.. I had MASSIVE rich conditions, ~ -20% on both banks 1 and 2. But the car actually ran amazingly for once, so I decided I would figure that out and deal with it later.

Yesterday on the way to work, I got a dreaded P0101 error (mass air flow sensor (MAF) is out of expected range). This instantly put my car into limp mode, so I pulled over and unplugged it/plugged it back in. I also tried wiggling the MAF cable around near the harnass and the plug, but it didn't clear the code.

The MAF was reading 4.2 g/s at idle, and was raising/lowering properly from the throttle. I limped my way home to get the car parked in my garage. Later, to rule out the MAF being faulty, I ordered a cheap aftermarket one off of amazon, just to throw in, see if it fixed the code and return it after. I cleared the code and installed the new MAF. However, the car is still stuck in limp mode. I scanned for codes again and don't have the P0101 but the car is still in limp so I'm assuming the code is still there but not cycling through.

Is it possible that my ICV being cleaned has caused this? Has anyone heard of this code being triggered from other electronics nearby? I also sprayed a bunch of silicone lube during the repair, but I can't see this causing this issue, but worth mentioning.

I think an alternative to the above is that maybe when I was doing the boot fixes, having the MAF wire dangling down might have possibly crimped a wire inside of it.

I've also seen it very commonly that the P0101 code and ICV stuck open codes often have the rich on bank1 and bank 2 codes alongside them.

Does anyone have any suggestions for next steps to solving this issue? My plan was to remove the airbox and upper intake boot today to try to get to the ICV plug to make sure it's in there snug, and also make sure the DISA valve plug is snug as well. But if this doesn't fix it, I'm kind of at a loss for what I can do..

Is there also a fuse that if blown could trigger this error code?

Sorry, I know there is a lot of info in here, but I'm really at a loss and any help would be much appreciated!!

Work I've done related to the above issues:
- Installed brand new fuel pressure regulator/fuel filter (Mahn, 3 weeks ago)
- Installed brand new new fuel pump (Bosch, 2 weeks ago)
- Installed brand new intake air filter (OEM brand, 2 weeks ago)
- Replaced lower intake boot
- Replaced some vacuum line for intake boot
- Cleaned ICV with Carb Cleaner
 

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Adaptations need to reset. They were so used to constantly adding fuel so that once you fixed the issue, they're surprised and need to learn. If you have inpa, you can clear adaptations. If you don't, just drive around until the DME relearns
 

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Discussion Starter · #3 ·
Hey Armen, thanks for the reply.

I'm assuming you're referring to the rich condition that I am facing?

This doesn't really solve my P0101 issue that's keeping my car in limp mode. I'm assuming I probably shouldn't be driving my car in limp mode either? Do you think the adaptations would be causing this as well? Seems kind of weird if it is..

I don't have INPA but I do have an OBDII scanner "BlueDriver" which I'm assuming doesn't have what I need to reset the adaptations
 

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When I took my intake manifold off to replace all my vacuum hoses, my car would struggle to idle afterwards. Fuel trims were sky high. I reset adaptations with inpa and the car ran great
 

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2004 330Ci 115k miles japan red
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You can reset DME adaptations using INPA or BMW Scanner 1.4.

I would clear the codes, drive it until the SES light comes on, then post the freeze frame data and trouble codes here.
 

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Discussion Starter · #6 · (Edited)
Thanks for the replies guys.

Is the car safe to drive in limp mode until the CEL comes on? It feels so sketchy when it's limping so just want to confirm so I don't damage anything :hmm:

Edit:
I'll amazon 1-day ship this:
https://www.amazon.ca/LZLRUN-INPA-D...rps=1&s=gateway&sprefix=K+DCAN,aps,147&sr=8-1

to myself for tomorrow as well so I can clear the adaptations. I should have an INPA cable anyways at this point.
 

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Discussion Starter · #7 ·
Just to clarify, when I say it's in limp mode, I mean it has the 'Cog of Death' on the gearbox indicator on the dash. I know MAF being unplugged can cause this, and I got the P0101 (MAF error) at the same time I got the Cog. However, the P0101 is gone since I cleared the code, but the Cog remains. Which is the cause of my confusion of the focus on adaptations in the replies.

Will clearing adaptations fix this, or is this unrelated to adaptations?

I have an INPA cable incoming for tomorrow. I'll drive the car around for a bit this evening to see if the CEL comes back, but driving it with the cog feels sketchy as it's limiting me to 3,000 rpm and the gear changing feels really clunky and ****ed.
 

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Use inpa from my signature.

Technically it is safe to drive in limp mode but it is very rough as you are experiencing. If you could get your hands on another maf to try out, that would help eliminate the possibility of a bad maf
 

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Discussion Starter · #9 ·
The "BMW Tools.." link? I'll get that going tomorrow once the cable arrives.

I drove around for about 20 minutes with original MAF and the CEL didn't come back, but still stuck in limp.

Tried also replugging in the DISA and ICV cables just to be on the safe side. Still in limp.

Jiggled the MAF wire around at the electronics harness and at the plug, didn't change the reading at all.. so not convinced it's wire related either.

A second MAF showed up that I bought on Amazon... it's a cheap aftermarket one for ~$50 but I figured it would at least be okay to see if the limp would go away. Installed, drove for a while, still limp.
Both the original MAF and the AM MAF were reading very similar g/s of ~4.20 at idle and were changing what seemed to be good with the throttle. I don't think it's the MAF but you never know with AM MAFs. I have a buddy with an e46 but his car has worse trims than I did, so his is probably worse than mine. I have a place www.germanparts.ca that's close to me, I'll have to see what their return policy is.. could try an actual OEM MAF for ~$500 and return it afterwards just to isolate out that it's a MAF problem.

At this point I think I'm **** outta luck until I can run the proper INPA/BMW Scanner 1.4 scans tomorrow after work (I ordered both to be on the safe side..). I will report back with an update after I can run a scan on the transmission ECU to see why it's in limp.. and maybe the CEL will come back for the P0101 that put it in limp in the first place.

In the meantime if anyone has any other suggestions I'm always open to trying **** out.
 

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2003 330cic, 2003 325iT
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For these types of components, you really need to stick to OE. VDO/Siemens for the pump, VDO not Bosch for the MAF, and Bosch for the o2 sensors. If you replace one boot, replace the other.

The cog of death will not reset, as it is a sign if an underlying issue, until you resolve the issue. If you have 150k miles or more, and your maf is original, get a new one (not ebay garbage). You need it.

Check your voltage at the studs in the engine bay with the engine on and off. 12.6 is good off, 13.7-14.6 with it on.

The other thing is you could have an actual issue with your transmission.
 

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Discussion Starter · #11 ·
Archbid, thanks for the response. But what do you mean the voltage at the studs? Not sure where you're referencing. I'll get my hands on a multimeter and check once I know where you mean.

Yeah I'm going to look into getting an OE VDO MAF from that parts store I linked above. Just got to see their return policy.. My car is at 270k km, so yeah ~160k miles. I'm not 100% sure it's the original, but it seems like it is.

I'm hesitant to think it's a transmission issue as the cog came on only when the P0101 triggered, which makes sense.

I don't think I'll be able to run the INPA tonight most likely, but as soon as I do I'll report back with the results.
 

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Discussion Starter · #13 · (Edited)
Bali thanks for that link! I'll check it out now. Looks like they have a good return policy.. the place I mentioned has no returns on electronics, go figure.

Looks like it's $250 once shipping and currency exchange is factored in. Still half the price as the local place and a return policy. So I went ahead and ordered - should show next week.
 

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2004 330Ci 115k miles japan red
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Looks like they have a good return policy
fcpeuro has a lifetime replacement warranty on all their parts.

Before you just blindly replace the MAF sensor, I would first see if yours is genuine BMW or VDO. Your MAF reading of 4.2 g/s at warm idle looks good.

Do continuity checks on all MAF sensor wires between the connector and DME connector in the e-box.
Might have to gently pinch the MAF connector female pins to improve connection. Sometimes they need that.
 

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Discussion Starter · #15 ·
That's a good point. I have the part ordered from FCPEuro... I think with this issue I've been a little impatient as this car is my main means of transportation to work. I think for the sake of saving myself time (and not necessarily money) I'll keep the order so that if the MAF IS bad then I won't be wasting any more time waiting for a new one. Worst case is that my existing MAF is good, and I'll just ship the MAF back for a return and swallow the shipping fee.

Is there a link I could follow for the continuity check? I'm a noob and still learning when it comes to electronics testing.
 

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Archbid, thanks for the response. But what do you mean the voltage at the studs? Not sure where you're referencing. I'll get my hands on a multimeter and check once I know where you mean.

Yeah I'm going to look into getting an OE VDO MAF from that parts store I linked above. Just got to see their return policy.. My car is at 270k km, so yeah ~160k miles. I'm not 100% sure it's the original, but it seems like it is.

I'm hesitant to think it's a transmission issue as the cog came on only when the P0101 triggered, which makes sense.

I don't think I'll be able to run the INPA tonight most likely, but as soon as I do I'll report back with the results.
Sorry about that. I was referring to the red positive terminal located on the left rear of the engine bay and the negative terminal that is near it inside the drug bin
 

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2003 330cic, 2003 325iT
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fcpeuro has a lifetime replacement warranty on all their parts.

Before you just blindly replace the MAF sensor, I would first see if yours is genuine BMW or VDO. Your MAF reading of 4.2 g/s at warm idle looks good.

Do continuity checks on all MAF sensor wires between the connector and DME connector in the e-box.
Might have to gently pinch the MAF connector female pins to improve connection. Sometimes they need that.
His car has 150k miles. Just replace the MAF. It is 100% original.

And replace the o2 sensors.

MAF reading at idle is not a good test of whether it is still good. Yes test the connector. But at this point the MAF is a maintenance item
 

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Discussion Starter · #19 ·
Sorry about that. I was referring to the red positive terminal located on the left rear of the engine bay and the negative terminal that is near it inside the drug bin
Hah! Never heard that referenced as the drug bin before, my multimeter is showing up today, so I'll take a peek in there tomorrow and report back :)

INPA also arrived last night, so will get that going for tomorrow hopefully as well!
 

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Discussion Starter · #20 ·
Hey everybody. So just to give an update, I've discovered the root of what caused my issue, and fixed the immediate problem of my car getting the P0101 and going into limp mode by resetting the adaptations.

Just a bit of a summary (point 4 is the fix):

1) My car runs really rich, but with the intake boot crack I had before (it was quite big) the resulting vacuum leak was compensating for how rich it was running, and brought it closer to an equilibrium.
- I could see this from when I replaced the lower intake boot it jumped from -5% to 2% at idle, all the way down to -25% at idle

2) When I drove the day after fixing the lean condition, my idle was already at -25% rich, and when I accelerated I saw that it peaked up to > -50% rich, and this triggered the P0101 code and threw the tranny into limp.

3) My new OEM VDO MAF arrived, so I swapped that out and drove around, car was still in limp mode. So I ruled out the MAF as being the root of this error. So I installed the INPA software.

4) Last night I ran the INPA and cleared the engine error codes and transmission error codes, and reset all 8 adaptations using INPA. This brought my idle trims down to -5% rich, spiking up to -20% at 3000rpm from my test

5) I drove around for ~20 minutes at various speeds and the CEL and Cog of Death didn't come back. Ran the INPA to check the error codes and the only remaining 2 were that both bank 1 and bank 2 are rich (expected).

Tonight I plan on swapping the new MAF out for my old one (I checked and it's a Siemens, which makes me think that it's either original or OEM replacement), just to see how similar my trims/air flow are. I'll do two similar drives to compare the brand new and old MAF and determine if the new one is worth keeping, or returning.

This however still leaves me with my engine running proper rich and I'm sort of out of ideas beyond testing for injector leaks, and replacing the O2 sensors. But before blindly replacing the o2 sensors, is there any way to actually debug if they're bad, or swapped? I saw online a way to test the injectors for leaks (pull the fuel rail out and prime the fuel pump, see if the injectors leak), but haven't seen much info on o2 sensors.

I'm leaning towards injector leaks as when I accelerate the engine doesn't get more lean, but more rich.. it also aligns with the fact that after I replaced my fuel pump, and fuel filter/regulator the problem got worse.

Any thoughts?
 
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