[xxdarkdragonxx]

Thanks Phil, the intake came sensor is located here :
picture from pelican parts


the engine I have is the N52B30 Engine displacement 2996 CC (182 Cubic Inches)

[Bufalo]

Originally Posted by Chamberlin

I ordered the blue connector portion of the MAF connector last night anyways, but it looks like I probably won't need to re-build the connector.

I am digging this waaaay up from the deep to ask Chamberlin if he ever did this connector replacement on his dad's E83. I've been chasing these exact issues on mine and have isolated the stumbling/stalling/poor-idle problems to something in the MAF wiring. I've switched out all kinds of fuel/air/timing related parts between my perfectly running N52K E90 and my won't-idle for crap N52K E83, and none of the sensors, actuators or solenoids have replicated the issue in the E90 or resolved the issue in the E83. I have no vacuum leaks.

When I unplug the MAF connector, the E83 suddenly runs and idles correctly. I've cleaned the contacts and swapped between 3 different known-good MAF sensors to no result. I've measured voltage at all four wires (the frequency measuring meter has four to the voltage measuring unit's five) when unplugged and everything at the connector seems correct - it's the same in both cars. I'm down to checking continuity on the wiring and measuring the voltage and frequency at the sensor wiring when everything is plugged in.

All that said, I did order the $6 connector; it's easy enough to dis- and reassemble just to eliminate the chance of trouble. A bad connection would be a problem whether the output is analog or digital.

So - has anyone else dug through this problem on a revised edition N52 with positive result?

[Chamberlin]

Originally Posted by Bufalo

I am digging this waaaay up from the deep to ask Chamberlin if he ever did this connector replacement on his dad's E83. I've been chasing these exact issues on mine and have isolated the stumbling/stalling/poor-idle problems to something in the MAF wiring. I've switched out all kinds of fuel/air/timing related parts between my perfectly running N52K E90 and my won't-idle for crap N52K E83, and none of the sensors, actuators or solenoids have replicated the issue in the E90 or resolved the issue in the E83. I have no vacuum leaks.

When I unplug the MAF connector, the E83 suddenly runs and idles correctly. I've cleaned the contacts and swapped between 3 different known-good MAF sensors to no result. I've measured voltage at all four wires (the frequency measuring meter has four to the voltage measuring unit's five) when unplugged and everything at the connector seems correct - it's the same in both cars. I'm down to checking continuity on the wiring and measuring the voltage and frequency at the sensor wiring when everything is plugged in.

All that said, I did order the $6 connector; it's easy enough to dis- and reassemble just to eliminate the chance of trouble. A bad connection would be a problem whether the output is analog or digital.

So - has anyone else dug through this problem on a revised edition N52 with positive result?

Just a head's up Bufalo, my dad's problems were fixed 100% by a new OEM valve cover, new plugs and coils. The idiots who worked on the car previously destroyed the Valvetronic gasket and there was a huge leak there (even after they tried filling it with RTV silicone LOL). I decided to play it safe and replace the whole cover, but I probably could have gotten away with just fixing the valvetronic gasket. I never had to change the blue MAF connector.

[Bufalo]

Thanks for the response! I've already done all that work on this car, so I'm in rogue territory.

[carscatscoffee15]

Originally Posted by E90joee

This is exactly whats been happening to my 07 328 but mines automatic so sometimes it does shutoff and it happens more when im driving more aggresive on the highway and its reving more but i also have a AA tune and headers i wonder if this will help

Did you ever find out if this was the culprit? I got this and the 2D59 fault code and am currently getting this checked out by a BMW Indy

I have an AA tune + exhaust + headers as well on a '13 128i

[E90joee]

Originally Posted by carscatscoffee15

Did you ever find out if this was the culprit? I got this and the 2D59 fault code and am currently getting this checked out by a BMW Indy

I have an AA tune + exhaust + headers as well on a '13 128i

Sorry cant help...my mechanic said its the plugs, coils...changed it and nothing. Then i changed the cam shaft position sensor and still nothing. I soon eventually sold the car.

[gT-BMW]

Originally Posted by PhaseP

This is a post of sharing my experience with a difficult to diagnose stubborn "system too rich" and occasional "Mass or Volume Air flow too high" codes being thrown with SES light and idle and some drivelability problems. After long trial and error and some testing and research I am confident I found the root cause and wanted to share since I saw other old posts with same problems with no conclusions to solutions from other people.

Some disclaimers: I am not a trained mechanic. What I am writing here is my own experience and I can't give any guarantees what I describe and explain is correct information or the right and safe way to work or do to a car. If you decide to use what I describe here, use your own judgement, safety, consult BMW shop manuals or trained mechanics. I am only sharing my experience with no claim that what I describe here is safe or correct way of working on the car.

Summary for TLDR people: MAF sensor connector was not making solid good connection due to too may connect disconnect cycles over 10 year service the life of the car and also due to what I believe too thin connector pins on the MAF sensor side for the connector pins used.

To start the long story, I have a first year (2006) US N52 (325XI) with a certain MAF sensor part number: 13627520519. Yours may be using different part number MAF. For instance 328 N52's are using different part number MAF even though the MAF from outside looks very much same physically and could be prone to same problem.

These were the symptoms I was having:

- Fault Code thrown: 2A2E Mixture too rich (OBD version: P0172 System too rich bank 1 )
- Fault Code thrown: 2A2F Mixture too rich (OBD version: P0175 System too rich bank 2 )
- Fault Code thrown: 2D06 value HFM to high (OBD version: P1424 Mass or Volume Air Flow Too High)
- Of course the SES light was on because of above codes
- On cold start up engine rpm was most often shooting up to between 2.5K and 3K rpm, then quickly going down.
- At warm engine idle, RPM needle was usually very close to 500 rpm mark or on the 500 rpm mark
- On idle, engine RPM was intermittently dipping, to the point of almost engine shutting down, but was recovering immediately.
- Sometimes idle RPM wasn't settling at all after coming to a stop. Normally it should have settled down to somewhere around 650 rpm after one or two seconds coming to full stop. But instead it was going down slow by slow and then up a bit and down a bit as if the engine was nervous and couldn't decide what to do.
- Car was usually feeling anemic at low rpms. Certain times it was becoming difficult to take off without stalling the engine (I have manual transmission), because even I was depressing the gas pedal it was as if something was reducing gas pedal input.
- Then a few seconds later if I had managed to take off without stalling, suddenly the anemic condition of engine was going away and I would feel this as a sudden forward thrust as engine all of a sudden was back to full power. This was happening not only during take off but also during low rpm driving, below 2K rpm. It was feeling like car had lost its mind and was not really following my gas pedal input at low rpms.
- But then some days, it had no issues. It was as if fixed itself. But only a few days later back to crazy idle rpms.
- There were no other fault codes related to these, only those three. And initially for a few months it was only the two too rich codes. 2D06 came a few months later, which turned out to be critical for me determining (or deciding ) the root cause of it.
- The freeze frame of the codes were showing short term fuel trim levels of negative 20% or so, don't remember well. This would explain the anemic condition of the engine it was not really getting too much fuel. The trim level means from my understanding, the car computer is adjusting (trimming) the amount of fuel it allows into the engine by that percentage than the ideal air to fuel ratio based on several sensor inputs as compensation, thinking it has really too much fuel to the amount of air going into the engine.

Eventually I believe I zoomed in on the real culprit and fixed this problem for good. The problem was being caused by the MAF connector wasn't making solid enough connection with the MAF sensor and resulting in intermittent disconnection of the MAF sensor from the computer. This was throwing off the computer, it was sometimes getting good value from the MAF, sometimes no (bad) value.

I had tried to clean the electrical connection pins on the MAF sensor and the cable side connector in the past as potential problem but it wasn't enough apparently. This time I ordered the parts to replace the connector, which are for my car:
P/N 12527516864 the connector housing
P/N 12527535589 rubber grommet for locking the cable loom to the connector housing
P/N 12527532371 x 5, the connection pins
P/N 61138366247 x 5, rubber grommet (seal) on the connection pins

My initial intention was to remove the connector and the connection pins and replace everything new. But I ended up replacing the connector housing and the locking grommet on the cable loom for the connector, because I decided to give a chance to cleaning the pins rather than replacing. Replacing would mean cutting them off and that would shorten the cable.

I used CAIG DeoxIt contact cleaner/conditioner which I had for electronics work. I am not sure if it is good to use it on auto connections due to the environment day live in, but on home electronics DeoxIT does clean up connectors very good. I also uses CRC QD electronic cleaner. The former removes oxidation, the later cleans up oil and dirt from my experience.

Below are steps with pictures coming next:

- Disconnected the battery negative connector on the trunk from the post and placed a paper between it and battery the post as isolation. I would be removing the connector pins and they would be touching each other, didn't want to cause any shorts or problems, so disconnected battery which was a requirement I think. (Don't close the trunk door after disconnection battery if you have one of those years that don't have a trunk manual lock, you won't be able to open the trunk with battery disconnected, just don't close the trunk )
- Then removed the connector from the MAF by lifting up the locking tab with a thin screw driver
- Removed the bottom part that locks the cable loom to the connector by prying up the two locking tabs. One got broken but I had bought new replacement.
- Jotted down the orientation of the connector and the wire colors going into it, so that I would be able to put them back at the same spots correctly.
- Pried open the middle section of the connector that locks the pins down.
- Pushed a paper clip on the top of the pins which pushed down the top spring tabs on them.
- Pulled down the wire for that pin to remove from the connector housing.
- Once all were out, I cleaned them first with the CRC Electronic cleaner. After that dried I sprayed inside of each connector pin with DeoxIt.
- I pushed the pins with the wires to the NEW replacement connector housing I had bought at the correct orientatio and order as before. Made sure they were pushed all the way in.
- Locked them in by pushing in the middle section of the connector housing, placed the loom locking bottom part.
- Cleaned the MAF connector side first with Deoxit and then CRC Electronic cleaner. I chose this opposite on the sensor since... my way of thinking.
- Pushed the new connector body to the sensor. It was much more solid in its place, hence it was important to use a new connector body.
- Reconnected the battery.
- Started up the car, and since then it has been all good. It has over a week now, SES light went off by itself, no idle issues, no erratic behavior. Simple fix!
- As usual after disconnecting battery I had to turn the steering wheel all the way side to side to get rid of the 4x4 error on the dash (an xi thing), and reset the time.

hey, thanks for this write up! ive been experiencing a drop in mpg, i used to get high 20s, now its about 18-19 mpg. ive got the bank 1 02 sensor heater malfunction code so i replaced both primary 02 sensor but still have around 19-20 mpg so then i got the p0175 code which led me to here, so now im going to try this, ive ordered all the part #s from fcp euro so lets see what happens.

[Three_thirty_I]

I remember reading this thread when PhaseP originally posted it. And to be honest, I didn't feel that it was affecting my car since I don't have any of the typical error codes associated with this, but, last year and the other night my car did something that makes me realise that this is a problem that my car suffers from, from time to time.

Middle of last year, I wanted to use my car, noticed that the left headlight was out, but drove anyway knowing that I have a spare bulb that I will fit when I return. On the drive the engine was just not behaving as normal, the idle was different when taking your foot off the throttle, and it was jerky. The kicker for me was when I gave it some beans later on, engine would simply not want to go much over 6000 rpm, it was actually stumbling! Will also mention that on a previous drive around that time I had observed the idle drop to around 500 rpm which never does. Anyway, so I got back home and in replacing the blown bulb I had removed the intake system to gain easy access to the light, and therefore had unplugged the MAF sensor. As I would always typically do, I blew into the contacts before plugging it back in. After that, the car was back to her normal self and not misbehaving.

Now fast forward to this past Friday - the bulb on the right side had decided to fail, and since I didn't have a matching spare, I ended up buying a new set which is slightly different. So I had the intake system and MAF out again, and just plugged it back in without doing any cleaning etc. Started the car and wanted to take some reference pics of the new bulbs in action, and while I was walking around the car I noticed the engine revs climb briefly and then settle - now this is something it has done from cold start a few times, but very seldom. Anyway, so took the car for a drive and realised that it wasn't feeling right, was jerky and idle was strange like the previous time. Before I drove back, I was able to get some electrical cleaner and cleaned the plug contacts for the MAF sensor plug, and for good measure I reset throttle adaptations. Sorted, for now, but I am going to have to investigate this some more then.

[juld0zer]

Just chiming in to give some more feedback about this fix:
- My car is an 06 manual 130i, so original N52 with the magnesium valve cover
- No faults ever logged but the throttle response seemed to go dull and randomly come back to normal
- Reseating the MAF connector did noticeably restore response

I purchased the pins (buy at least 7 as the cable is extremely short so you will drop at least one or stuff up the crimp), grommets and connector.
- I was unable to find the correct crimp tool that crimps the pin to the wires and the grommet in one go. Instead i just used the crimp tool for 0.5mm2 wire and shaved off the bulging grommet rubber to fit. Some silicone spray on your fingertip then dabbed onto the ribs of the grommet aids reinsertion
- Take the airbox out. You can do it with the airbox in place but it is so much more comfy with no airbox in the way because the cable is so short
- I reckon you could get away with just replacing the plug connector like OP did. I believe this is the primary cure as it is indeed a lot more snug, requiring a good firm push to fit. BMW workshop test leads also have the same blue connectors (some trivia). Maybe these are the heavy duty versions designed for frequent use?
- Don't use a paperclip to disengage the pins. Once you fold back the flap that acts as the double lock, you can use the same tool you used to open the flap to press down on the lock tab of the pins whilst gently pulling them. A paperclip may be too thick and crush the lock tab too much.
- Disconnecting the battery is good practice but not necessary if you want to avoid doing resetting the DME trims etc for testing purposes (minimising variables). Instead, I locked the car and let it go to sleep (wait 10mins or until all lights are off inside). This is your choice, however.

[Richwm]

Thank you PhaseP, I was getting codes P0113 and P111F with a IAT temp of -40 on my scan gauge II that would come and go. I replaced the MAF then two weeks later I got the faults again. I found your post ordered the parts and just replaced the connector. I have high hopes that this will fix my issues as well. After replacing the connector it seems to fit much more secure than before. I checked my scan gauge and the IAT temp was back to a reasonable temp so I cleared the faults and I guess I will just wait and see.

[PhaseP]

Originally Posted by Jonaa24

HI, I have a E90 2010 328i N52K, and the car has a poor/rough idle and something is throwing off the computer (DME) and i think is the MAF sensor because when I unplugged it the rough idle is gone and the car stays runinng longer, but dies, and the only code i got is: 2D06 air mass system
i have replaced: eccentric shaft sensor. both camshaft sensors, crankshaft sensor, MAF, MAP, VANOS SOLENOID, DME
Any help would be very appreciated

Look for air leaks.
When MAF is disconnected computer calculates the amount of air entering into the engine from engine rpm, current temperature etc. based on an engine model.

When MAF is connected, MAF measures the amount of air entering into the engine and tells to the computer. But MAF can only measure the air that flows in over it, i.e. it measures only the air that flows from the air intake filter box, which the MAF is connected right after it.

If any additional air enters into the intake stream after this point, MAF will not be aware of it.

And if this happens, MAF tells engine this much air is entering the engine, but reality is more than that. And engine computer gets confused. It tries to compensate the error amount as much as it can, but if it is too much it won't be able to.

Look for air leak (air entering after the MAF) at the crankcase breather hose that comes from the back of the valve cover into the intake. Look for air leak from the PCV valve nipple that is at the left rear of the valve cover. It has a dust cover plug looking thing, if that hasn't fallen of and lost already.

Look for cracks on the valve cover.
Those are the places that comes to my mind to check for.

[dtwjhwk]

think I am having the same issue, but not much of an electrical guy with the solder. Would it be feasible to just replace the cable harness that goes into the MAF sensor housing?

[PhaseP]

Read the first few posts again, there is no soldering involved.
Just clean your connector first, but clean good with a contact cleaner.
Also check if your oil filter housing is leaking. What I noticed initially the oil filter housing gasket starts to leak very slowly and hot oily steam starts coming out of there. This then gets deposited on the MAF connector area, attracting dirt also. The sound deadening under the trunk also absorbs this fume and when car is parked it starts to drip down from in very small amounts by steadily every day. I am thinking this has something to do with it.

The replacement connector housing seats tighter inside the MAF and this not only keeps connectors tights it seals better too.

[dtwjhwk]

Got it.. no leaks in my oil filter housing as I replaced the gasket about 6 months ago. Ordered a new connector from the dealer, so will give it a go tomorrow!

[HydroxFrost]

I believe I'm having this problem right now but my car is tuned to operate without a maf sensor, I have the IAT circuit high code but on data logs it doesnt abnormally dip at all. System too rich both banks and car completely falls on its face at 6000 rpm, idle seems like yours. Not sure what to think.

[xavi718]

Originally Posted by PhaseP

This is a post of sharing my experience with a difficult to diagnose stubborn "system too rich" and occasional "Mass or Volume Air flow too high" codes being thrown with SES light and idle and some drivelability problems. After long trial and error and some testing and research I am confident I found the root cause and wanted to share since I saw other old posts with same problems with no conclusions to solutions from other people.

Some disclaimers: I am not a trained mechanic. What I am writing here is my own experience and I can't give any guarantees what I describe and explain is correct information or the right and safe way to work or do to a car. If you decide to use what I describe here, use your own judgement, safety, consult BMW shop manuals or trained mechanics. I am only sharing my experience with no claim that what I describe here is safe or correct way of working on the car.

Summary for TLDR people: MAF sensor connector was not making solid good connection due to too may connect disconnect cycles over 10 year service the life of the car and also due to what I believe too thin connector pins on the MAF sensor side for the connector pins used.

To start the long story, I have a first year (2006) US N52 (325XI) with a certain MAF sensor part number: 13627520519. Yours may be using different part number MAF. For instance 328 N52's are using different part number MAF even though the MAF from outside looks very much same physically and could be prone to same problem.

These were the symptoms I was having:

- Fault Code thrown: 2A2E Mixture too rich (OBD version: P0172 System too rich bank 1 )
- Fault Code thrown: 2A2F Mixture too rich (OBD version: P0175 System too rich bank 2 )
- Fault Code thrown: 2D06 value HFM to high (OBD version: P1424 Mass or Volume Air Flow Too High)
- Of course the SES light was on because of above codes
- On cold start up engine rpm was most often shooting up to between 2.5K and 3K rpm, then quickly going down.
- At warm engine idle, RPM needle was usually very close to 500 rpm mark or on the 500 rpm mark
- On idle, engine RPM was intermittently dipping, to the point of almost engine shutting down, but was recovering immediately.
- Sometimes idle RPM wasn't settling at all after coming to a stop. Normally it should have settled down to somewhere around 650 rpm after one or two seconds coming to full stop. But instead it was going down slow by slow and then up a bit and down a bit as if the engine was nervous and couldn't decide what to do.
- Car was usually feeling anemic at low rpms. Certain times it was becoming difficult to take off without stalling the engine (I have manual transmission), because even I was depressing the gas pedal it was as if something was reducing gas pedal input.
- Then a few seconds later if I had managed to take off without stalling, suddenly the anemic condition of engine was going away and I would feel this as a sudden forward thrust as engine all of a sudden was back to full power. This was happening not only during take off but also during low rpm driving, below 2K rpm. It was feeling like car had lost its mind and was not really following my gas pedal input at low rpms.
- But then some days, it had no issues. It was as if fixed itself. But only a few days later back to crazy idle rpms.
- There were no other fault codes related to these, only those three. And initially for a few months it was only the two too rich codes. 2D06 came a few months later, which turned out to be critical for me determining (or deciding ) the root cause of it.
- The freeze frame of the codes were showing short term fuel trim levels of negative 20% or so, don't remember well. This would explain the anemic condition of the engine it was not really getting too much fuel. The trim level means from my understanding, the car computer is adjusting (trimming) the amount of fuel it allows into the engine by that percentage than the ideal air to fuel ratio based on several sensor inputs as compensation, thinking it has really too much fuel to the amount of air going into the engine.

Eventually I believe I zoomed in on the real culprit and fixed this problem for good. The problem was being caused by the MAF connector wasn't making solid enough connection with the MAF sensor and resulting in intermittent disconnection of the MAF sensor from the computer. This was throwing off the computer, it was sometimes getting good value from the MAF, sometimes no (bad) value.

I had tried to clean the electrical connection pins on the MAF sensor and the cable side connector in the past as potential problem but it wasn't enough apparently. This time I ordered the parts to replace the connector, which are for my car:
P/N 12527516864 the connector housing
P/N 12527535589 rubber grommet for locking the cable loom to the connector housing
P/N 12527532371 x 5, the connection pins
P/N 61138366247 x 5, rubber grommet (seal) on the connection pins

My initial intention was to remove the connector and the connection pins and replace everything new. But I ended up replacing the connector housing and the locking grommet on the cable loom for the connector, because I decided to give a chance to cleaning the pins rather than replacing. Replacing would mean cutting them off and that would shorten the cable.

I used CAIG DeoxIt contact cleaner/conditioner which I had for electronics work. I am not sure if it is good to use it on auto connections due to the environment day live in, but on home electronics DeoxIT does clean up connectors very good. I also uses CRC QD electronic cleaner. The former removes oxidation, the later cleans up oil and dirt from my experience.

Below are steps with pictures coming next:

- Disconnected the battery negative connector on the trunk from the post and placed a paper between it and battery the post as isolation. I would be removing the connector pins and they would be touching each other, didn't want to cause any shorts or problems, so disconnected battery which was a requirement I think. (Don't close the trunk door after disconnection battery if you have one of those years that don't have a trunk manual lock, you won't be able to open the trunk with battery disconnected, just don't close the trunk )
- Then removed the connector from the MAF by lifting up the locking tab with a thin screw driver
- Removed the bottom part that locks the cable loom to the connector by prying up the two locking tabs. One got broken but I had bought new replacement.
- Jotted down the orientation of the connector and the wire colors going into it, so that I would be able to put them back at the same spots correctly.
- Pried open the middle section of the connector that locks the pins down.
- Pushed a paper clip on the top of the pins which pushed down the top spring tabs on them.
- Pulled down the wire for that pin to remove from the connector housing.
- Once all were out, I cleaned them first with the CRC Electronic cleaner. After that dried I sprayed inside of each connector pin with DeoxIt.
- I pushed the pins with the wires to the NEW replacement connector housing I had bought at the correct orientatio and order as before. Made sure they were pushed all the way in.
- Locked them in by pushing in the middle section of the connector housing, placed the loom locking bottom part.
- Cleaned the MAF connector side first with Deoxit and then CRC Electronic cleaner. I chose this opposite on the sensor since... my way of thinking.
- Pushed the new connector body to the sensor. It was much more solid in its place, hence it was important to use a new connector body.
- Reconnected the battery.
- Started up the car, and since then it has been all good. It has over a week now, SES light went off by itself, no idle issues, no erratic behavior. Simple fix!
- As usual after disconnecting battery I had to turn the steering wheel all the way side to side to get rid of the 4x4 error on the dash (an xi thing), and reset the time.

Question; ¿ you only replace the connector housing? Not the pins ?

[PhaseP]

Originally Posted by xavi718

Question; ¿ you only replace the connector housing? Not the pins ?

Not the pins. But must clean them good.