35d map sensor replacement
 

My 13' 35d is throwing a hard reduced power warning. Finding MAF and MAP related codes, cleaned the MAF and attempting to replace the MAP sensor. How does one go about removing the bottom intake tray so I can get at the sensor?



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For map sensor it's on the top driver side near the firewall. You just need to remove the engine cover and air filter box to get to it.
Unscrew the maf band clamp pop off plastic house to maf, unplug maf. Unclip the intake hose from the front. Pull up on the filter box to pop itout. Be careful of any wires that could be in the way

Yep got that far, but not sure how to get the lower cover off? Looks like it is mounted in 4 spots, do I just pull up on it hard and fast?

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Yes, you can try pulling at one corner first in the back... they pop out kind of hard if you haven't removed it in a while.

Pry it up with a large screw driver. Pop off one corner at a time.

That worked, MAP sensor was gummed up waiting on replacement.

Did you have any trouble getting the MAP sensor out? Any issues with the rubber grommet that holds it? I'll be removing mine to soak the intake in purple power.

Map sensor came out easily once I was able to get the cover off.

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Just cleaned mine in purple power..lots of soot came out. also got in there with a cotton swap until it was sparkling. still getting errors.

just ordered a new one from shopmercedesbmwonline.com
using discount code "take5"
came out to $78.32 shipped.

And why are you guys thinking bad sensor and not an air/seal leak or similar??

I couldn't find a leak, ISTA/D suggested MAP sensor was not within spec when doing functional test.

its not easy to tell if it's the map sensor because on this thread

https://xoutpost.com/bmw-sav-forums/...s-codes-2.html

user is getting a mirad of different codes.

and on this thread

X5 35D 2011 Codes - Page 2 - Bimmerfest - BMW Forums

there is another user with different codes.

so you might get a combination of codes I guess it depends on what software you are running.

for me the codes are primarily

4862 Air system, Air to EGR mass flow, plausibility
i get this code after about 12 miles of driving every time. cleared it a dozen times so it's consistent

and this one
3F03 boost pressure sensor signal
I only got this code once after the dealer kept the car to change the frm module. Im assuming they left it to idle for a long ass time and that's how the fault got logged.

just want to leave this here so that if i fix it someone else can find it.

replacing MAP sensor resolved the issue for me, see the following thread for how to diag in ISTA/D

https://xoutpost.com/bmw-sav-forums/...ap-sensor.html

replacing the map sensor fixed the issue for me as well. 110,000 miles

so after 650 miles the map sensor error came back. it seems it takes a very long time for the error to log. as I plugged in ISTA multiple times and could not read anything just the CEL

It appears at this point the fault is related to EGR checks performed by the MAP sensor since the CEL comes on only during coasting at low or no acceleration it appears its that specific test that I am failing.

when driving different roads that do not have downhill/coasting i can drive much farther without the cel.

My egr is deleted so Its a unique issue and will check with the tuner.

Which codes came back? The pressure one is map, but the egr can be maf, egr leak, or leaky air piping which looks like a bad maf to the dde

this is the code that came back this time it seems like it took 650 miles for it to be logged.

00433A DDE: Charge-air pressure sensor, range.


seems like a very MAP specific code to me? interesting that i never got this code before with the old MAP sensor

Im interested to hear your opinion on this.

Not sure, try re seating the plug for the map sensor? Is the grommet that map goes into In good shape, did it feel loose going in?

I don't know if this code refers to boost being too high or too low than expected. In that case it could be a boost leak or something with the turbo actuators (vac lines?)

Do you remember if it came up during hard driving or normal driving?

Can i have your old grommet? My map popped out once, so I made a screw to hold it down and snug but don't trust it.

Egr plausibility at coasting , hmmm. Do you have torque for android? I have good pids to diagnose a possible issue, plus it seems to log faster than carly. Carly is such an annoying program, Im using my friends license, but i can't update it because then it tells me that my adapter is not compatible and wants me to buy theirs. Pfft... I use it to quickly scan for codes, but I will see if Rheingold says anything about that code if I can figure out how to look up by codes!

I don't have the egr anymore since i am deleted so how would we know trough pid's if the DDE is checking for increased air pressure while coasting? we would just see normal pressure.

I like the idea tho:thumbup: Ill get torque, gonna take a while as I do not have a droid device or adapter

I can't figure out how to pull up the diagnostic steps in rheingold ista-d for a specific code. Searches turn up nothing... This is what I could find when I go to the functions under DDE for the map sensor.
What is odd is that I can search for the codes listed in here, and it comes up as documents, but 433a does not. I wonder if its a code more related to maf.


EGR won't change the intake pressure, that's the turbo actuators and fueling that does it. But since you are deleted maybe your tuner has an idea what it could be.
Or perhaps it is a code that points to some maf plausibility reading and you might need to use rheingold/ista-d to reset the adaptations for the MAF/oxygen-lambda sensor?

i found this in wikipedia

"The MaP sensor is then used for rationality checks and to test the EGR valve. The way they do this is during a deceleration of the vehicle when there is low absolute pressure in the intake manifold (i.e., a high vacuum present in the intake manifold relative to the outside air) the powertrain control module (PCM) will open the EGR valve and then monitor the MaP sensor's values. If the EGR is functioning properly, the manifold absolute pressure will increase as exhaust gases enter."

So it could be a tune issue. If the tuner didn't set it up to allow a full egr race pipe, it still might be running those checks.

It might also test the throttle valve which is in front of the egr. Another reason why I don't like egr delete pipes. On my tdi, I left the egr to keep that throttle plate which can save you in case the engine runs away on oil vapour.

So the issue ended up being the tune did not address all emission related codes. after much frustration and denial from the tuner I got a tune from a different tunner Dima at DUDMD and have had no issues after 1,000 miles. The error always came at around 20 miles. So I am pretty sure it's gone.

What tune where you running? I have a Malone with deletes.

Pretty sure the old tune was from member bawareca

I had the same issues , turned out to be the MAP

Anyone else have the map sensor blow out of the intake after replacement? Mine was in for about a week when it threw codes. Not only did the sensor back out of the manifold, but the rubber grommet is gone as well. Any ideas what could have cause this?