Learn the DMTL System! - P0442 EVAP Micro Leak Diagnosis on BMW E90 DIY

The EVAP system on a BMW is slightly different from most other American or Asian cars. It employs something called the DMTL to diagnose leaks on the system. In this video I talk about what that module is and how it works so that you can better understand how to diagnose EVAP leaks.
The codes you might get for EVAP leaks are:
P0442 Evaporative Emission Control System Leak Detected (small leak)
P0455 Evaporative Emission Control System Leak Detected (gross leak)
Both can be diagnosed using this method.
If you're looking to get a good smoke machine, I can recommend this one (which I use in this video):
amzn.to/3phMQRS
However the price has gone up since I first reviewed it. AUTOOL makes a cheaper version, but it doesn't have flow or pressure gauges:
amzn.to/3mopF6u
There is an even cheaper tool that is made in the USA, however it doesn't look much different than the DIY version I made years ago:
amzn.to/32tpvUt
DIY Smoke Tester:
• DIY Smoke Machine For ...
00:00:00 Intro
00:00:23 How EVAP systems work
00:04:39 How BMWs are different
00:07:25 How to test any EVAP system
00:10:09 Where to hookup your smoke machine
00:11:31 Turn on the smoke machine and find the leak
00:12:27 How to close the "vent valve" to seal the tank and find the real leak
00:14:13 Where my leak actually is
00:14:49 Replacing the defective part
00:25:59 Verifying the repair
00:26:57 Wrap-up
This video is for entertainment purposes only. 50sKid assumes no liability for any repairs or modifications performed by the viewer as a result of the information contained in this video.

[@daigrt770]

When you remove these types of filters with the built on lines, use about 10 ft of old speaker wire. Tie it to the old lines, pull the old lines out and then use the speaker wire as your guide line to route new lines. One of my trainer's over the years handed that trick down to me.

[@chadriddle3517]

Great information Jason, really appreciated how detailed you broke the process down!

[@ApaX1981]

I had a very weird problem with my M54 in the E46. It had a problem that the engine would drop all torque for a split second if you would go from coasting to 80% (or more) throttle. This would only happen when the engine was hot. It turned out to be a faulty tank filler cap seal (was in multiple pieces). Via all the hoses the engine would draw in vapors directly from the tank. I found it by simply disconnecting the vent solenoid. This would make to issue disappear. I added a LED to the signal wire of the solenoid + extension cable so I could see what the DME was doing. Turns out DME is controlling the vent solenoid proportional (and only when hot). It would full open the valve on wide op throttle. A side not. The US and EU systems are different.

[@michaelblacktree]

Wow, you're not kidding! That evap system is pretty funky.

[@thomasatkinson5414]

Thanks for keeping it real and not editing out all the hard stuff

[@Dosalt]

Watching this after hours of research and learning about the system. Wish I saw this video before

[@Mark-th1gn]

I don't have a E90 still going to absorb all the knowledge thank you based 50skid

[@thebywall]

THANK YOU. I've been trying to diagnose this chronic DMTL code on my E60. Already replaced the pump with a brand new piece but no success. Can't wait to gain insight on this topic so I can hopefully clear the code for good.

[@eddierofl]

Awesome vid! Thanks for the info on the EVAP system. Really handy to know! I've had a faulty fuel level sensor in my E39 for ages, and I know I should replace it, but it's just one of those issues you learn to live with haha. Might finally tackle it after seeing this.

[@marknoir]

Thank God for this video! It’s THE ONLY ONE TO MENTION THAT THE VENT VALVE IS INSIDE that DMTL pump! I got codes telling me the “vent valve” is bad, but I couldn’t find it. What confuses me, is that as soon as I got the check engine light in the vent valve, my secondary air pump stopped working - no 12v going to it. (2004 bmw M3)

[@bobflannagan7262]

Thanks for taking time to explain the system. I have a stubborn E36 328i which I now believe I can solve. Thanks from a new subscriber.

[@stepheno9569]

Great vid, at some point everyone who is a bmw enthusiast is going to have to mess around with a failure in this system at some point.

[@e.a.7265]

Good video Jason. I would wear a mask when removing the fuel pump as the fume can be nauseous.

[@DrRestorations]

My 2008 BMW 528i started to show P0442 after replacing the fuel pump. Also, the fuel gauge on the dashboard shifted causing a run-out-of gas on the highway. So, the level should be adjusted prior to installation (which I failed to do).

[@edwinbencosme7344]

Gees. I replaced that part on my friends e90 last year. Its very annoying to replace 😂. Guess as they age they crack. I guess It’s starting to be a common part to replace

[@rowen898]

Always tie down the hoses with some string. I broke that hose once and luckily had the string to fish the new one through.

[@hermanrogers1325]

A job well done for yourself and save yourself a lot of money

[@twinturbo8304]

Good Video My fuel pump evap line leaked Pain to replace

[@ignacioromero5014]

for the Ring removal, PB Blast inside the little slot and inside the ring to plastic plastic. It will be easy them.

[@MartyMitchell92660]

Good video! I wouldn't use a vacuum cleaner around the top of a partially opened gas tank. Better to use compressed air to blow the dirt away. Vacuum cleaner and gas fumes = bomb.

[@mikelm7398]

Hello Jason, I wish you all the best for 2022. love greetings mike

[@SamAbraham]

Perfect timing lol just got a DMTL code last night

[@user-vg2eg6zw1j]

thanks great video seems like some silicone maybe would have fixed it instead of a new part

[@RajeshSingh-ps8wv]

Thanks for the informative and detailed video!

[@shakathevirgo316]

Thank you for you work and tips happy new year sir awesome videos

[@samwell9540]

Hey what is that testing probe you used? I am having trouble finding a suitable solution.

[@radosvetyordanov4351]

My idle stall problem was LPG gas tubes not sealing the drilled holes on the intake Lol the last thing I was suspecting 🙈😁

[@JB-B58]

Can you explain what you did and what was the issue bro ?

[@Delvii]

Hey I’m new to doing maintenance on my own car I have an e92 335i 2012 with the p0440 code I’ve replaced the purge valve and now doing a smoke test just wanted to know what tool did you use to close the vent valve or where can I buy it from thanks in advance and great video I learned a lot

[@peepeeskillz]

did you ever find a tool for this?

[@samwell9540]

Yeah did you manage to find anything?

[@tylereubanks1613]

He shows you exactly how to ground off the valve to close it off . 12:44

[@rightcoastimports]

I am in the middle of doing this and I do not hear a click on the pump when I apply ground to pin number 3 (black/green) does that mean the pump is not working?

[@jgeorges3061]

AWESOME video/info thanks for sharing. Merry xrsmas

[@hussam842003]

Very nice teaching video, I loved how you explained it! Thank you! Did you even smell gas in the car to determine that was coming from the fuel pump housing? also what was the symptoms that you had to do check for leaks?

[@50sKid]

Nope the seat covered up any fumes and they never got into the car

[@hectorrivera7626]

I have a 1999 bmw 328I that is leaking gasoline so you have a video to fix it?

[@user-ud5hs3lf4c]

Hi Jason, Thanks for your great videos as usual, I got a question, is there any other configuration or location for the DMTL Pump? I have been dealing with a PO171 Code and chase the Vaccum line all the way to the Charcol Canister and guess what? THERE IS NO DMTL Pump, so that vaccum line is sucking a bunch of air into the Throtle body and MAF sensor does not read it, there are three tubings into the Canister 1.- The Vaccum line from the Engine about 1/2" in Diameter 2.- The Line that goes to the other side of the Car (Passanger side) where there is supposed to be a filter, THERE IS NOTHING (1/2" Dia) 3.- A Smaller size tubing that goes inside the car to the Fuel Tank So when the Car is running Fuel Trims are around 25 to 30 (very high), but when I got to a stop light, the Check Engine Light turns on and start shacking like Crazy, sometimes goes into LIMP MODE Since I dont have a DMTL Pump I am going to disconnect the Purge Soleniod, to avoid openning the line all the way ang get a huge Vaccum leak What do yout think, Any idea is welcom By the way, this is a BMW, 2010, 335i, N54 Engine and E90 Chassis Thanks

[@moosy]

Can this cause a crank no start? For instance if you leave it overnight and it keeps loosing pressure

[@daveparks3993]

Why not just seal the crack….JB weld!

[@maxjohnson6816]

works for about 30 seconds, then leak smell comes back. the DMTL pushes air into cabin

[@carlosalvarezrivas416]

I just got today a 2A1A (tank ventilation system,function) is basically a small leak should I do the same ? Thanks

[@peepeeskillz]

Would this leak cause my evap monitor to not go ready? I've been driving my car for at least 300 miles and evap monitor won't ready up. I started to notice my car smells like gas after shutting it off in the garage. Smell is coming from left rear wheel well somewhere.

[@jhncvngh]

Mister Jason what is your great weight loss secret ?? Also thank you now I know how to ochange a EVAP BMW system on my E90

[@HaroRider03088]

Yea, I have noticed, he has lost a lot of weight.

[@50sKid]

I’ve been biking 5 days a week

[@cperez122055]

I have a 2017 F25 X3 and am getting P0456 - small leak detected; where is the NVLD Pressure Switch and dust filter?

[@trishonya]

I recently got this to and my check engine light is on!

[@arielcastro34]

I have p0446 n p0456 has anybody found what those codes could be,? Pls help

[@cperez122055]

@@arielcastro34 I bought a pressure switch and brought to my mechanic to replace. Once the new part was installed, the code has not come back.

[@ethiopianeyes]

I had a p0444 code on my e39. Turned out to be the fuel pump gasket as I was smelling fuel in vehicle and fuel would leak out the bottom on fuel tank. Now dealing with p0186 or 7code. I forget Intake manifold gasket showed a puff of smoke. Damn cali smog restrictions. Car has been sitting since may tags out if date.

[@50sKid]

Strange, that’s a fuel temperature sensor code. I didn’t know the e39 had one. But, look for it on realoem.com and you’ll find where it is and you can replace it

[@mneste]

Hello 50sKid. Perhaps you might have an idea of what's going on. I have an '04 X3 with the 2.5L and it seems that every time I fill up the gas tank, right afterwards when I try to get going from a stop, the engine hesitates. There was a couple of instances when it would stall. I have been hunting for the culprit for years now. I have recently replaced the Fuel Filter, Purge Valve, CAM Intake and Exhaust position sensors, PCV system replacement, and yet nothing seems to be helping and there are no codes that pop up which is even more frustrating. Recently while on the hwy, I got multiple misfires and no power when pressing the gas but after a few moments, it somehow cleared itself and everything was like normal (this was after going through a half a tank of gas). This is the first time that happened and the only time. This prompted the CAM sensors, but now the car wont start on the first try, and so it looks like I'll be going back to the originals. I have now ordered the fuel pump and the vapor leak detection pump. I'm out of ideas other than that. It drives perfect for the most part, however the hesitation will occasionally happen at a stop and getting going outside of the recent fuel up situation but it certainly happens always after a fill up. This makes me think it is a vapor build up in the fuel tank and that the purge valve would fix it but it hasn't. Any information would be appreciated. I have smoke pressure tested the intake and I have no air leaks anywhere. Have replaced the intake flap as well.

[@kennethsibert1067]

I like your video. Can you show where the crack is? Otherwise was it just the O rings? Thanks.

[@Buglife59]

I would do this on a very low tank of fuel

[@DespiertaVe]

Where can i get that ground black wire or how can i find it in a autoparte store ?

[@princetonjackson827]

Which pin is number 3? Bottom left or right

[@ranjitranjitsingh9189]

BMW 2 series fuel pump in tank or not let me know please

[@alpinen52ny79]

I been struggling with code 2A1A I already replace the purge valve - charcoal canister and solenoid. I did perform a test with ISTA-D to see if the purge valve was activating and yes it is, at this point I don't know what else to do , if anyone knows let me know 🤦🤦🤦 …..

[@50sKid]

Ista will have a whole diagnostic routine for that code. Did you go through it?

[@carlosalvarezrivas416]

Did you ever figured out I just this today 🥲

[@stevecampanale8402]

I have a 08 E90 with the same code. Do you remember what the pressure and flow gauges were when the leak was present? My machine is not indicating a leak but it keeps setting the code.

[@eduahpeteschwenk8453]

Help. I have a e90 330xi and it has the red steering wheel light of death. So frustrating!

[@markhamilton8681]

Great video as usual. Would you be able to do one to explain the P171 and P0174 codes (system too lean). I've taken it to a BMW shop, they did a smoke test, couldn't find a leak. This is after I had the CCV valve replaced. The codes insist on returning. Any idea what that could be? Thanks.

[@fonki1149]

Oil change fixes the problem sometimes

[@joshuaestrada1652]

What is the part name? I am needing to purchase for a 08 750LI. Can you share?

[@its_me_lo1142]

What pin would you need to ground on a 99 328i pre face lift.? These wires only. Red/white, black/green and blue/orange? Thanks

[@omaresparra1989]

Do you need the car switch on to do close the vent valve??

[@faridzmohd6511]

Fault code EA and E9 catalaytic converter efficiency.anyone know what is the problem?

[@jguitar29]

Damn that was a good video

[@Triune316]

Is the grounding of the pin #3 also same for e46 in order to do Evap smoke test? Thanks

[@victorleon2146]

Muy buena clase

[@rahmanr112]

Will you ever do a Oil Dipstick Retrofit ?

[@alexedward1250]

Nice video.

[@bradleymanuel7553]

I need help 50s kid my transmission light came on my 2003 330i . I thinks it's on limp mode. What can I do to fix it 🤔

[@50sKid]

you need a bmw scan tool to read the code and further diagnose

[@2012isRonPaul]

21:50 - that looks like u just gutted a Predator LoL probably better to do it with an empty tank tho

[@danielcastaneda5249]

Do you have a video on a P0411?

[@jondufrene5873]

Looking slim bro!

[@ledwysdelgado7304]

Has anyone dealt with a p1446 before?

[@seanpaul3050]

If you were testing for engine vacuum leaks, would you still need to close that DMTL valve ?

[@50sKid]

No, because the purge solenoid is closed unless the engine is under wide open throttle

[@seanpaul3050]

@@50sKid okay thanks

[@uptownimports-foreignautor5338]

Next time put a piece of wire on the hoses so u can just pull them back over some of these can be a real pain if u don't do this.

[@StevesBeyondRepair]

Goes to show you how useless a smoke machine is at finding this small evap leak(just like on my cooper) literally no smoke out of that crack in the pump housing....

[@isrealperez9069]

You know I believe that even if it's hard for us to imagine how hard is it for a technician that works in for BMW I don't think they know too much all they do is what we know with plug it in and cuts it from tested from there well that's out here in Connecticut they're no good

[@xcuber123]

Always wondered how the car knew there was an evap leak

[@manuelcastaneda7102]

Great video , you been losing some weight

[@DavidN5X]

👍

[@sksuppressor756]

WOW have you lost weight!

[@50sKid]

Thanks!

[@user-qf6yt3id3w]

What an absolute nightmare of a job.

[@mike-yp1uk]

Bmw and every other manufacturer makes the access hole to small. Lol They don't want average people touching the job so they put us thru the engineering wringer

[@edwinbencosme7344]

Second!!

[@teufelhunden2820]

FIRST!!