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What is a "diagnosis pump" or "DMTL pump"?

134K views 10 replies 5 participants last post by  31st330i 
#1 ·
Today when I had my 330i in to get the control arms replaced (see Control Arms thread) it looks like they replaced something called a "DMTL pump" due to a service bulletin that apparently called for its replacement.

The part they replaced is identified as
16 - 13 - 6 - 756 - 440 DIAGNOSIS PUMP

The service bulletin is identified as
SIB 121300 D.C. 0016160100

BTW my service advisor didn't mention it at all and it appears all the way at the end of my invoice.

Anybody knows what the heck this is all about? :dunno:
 
#2 ·
rg said:
Today when I had my 330i in to get the control arms replaced (see Control Arms thread) it looks like they replaced something called a "DMTL pump" due to a service bulletin that apparently called for its replacement.

The part they replaced is identified as
16 - 13 - 6 - 756 - 440 DIAGNOSIS PUMP

The service bulletin is identified as
SIB 121300 D.C. 0016160100

BTW my service advisor didn't mention it at all and it appears all the way at the end of my invoice.

Anybody knows what the heck this is all about? :dunno:
bump (way old thread)

I just had the same thing replaced. what and where is it? I thought I remember the service advisro saying that it had something to do with the evaporative emission controls.
 
#3 ·
31st330i said:
bump (way old thread)

I just had the same thing replaced. what and where is it? I thought I remember the service advisro saying that it had something to do with the evaporative emission controls.
Looks like it is part of the fuel system (Group 16). The full part name is "Leak Diagnosis Pump". I think it is the gizmo that turns on the Service Engine Soon light when you leave your gas cap off :D
 
#4 ·
Terry Kennedy said:
Looks like it is part of the fuel system (Group 16). The full part name is "Leak Diagnosis Pump". I think it is the gizmo that turns on the Service Engine Soon light when you leave your gas cap off :D
thanks. well, the reason I ask is because the service engine light did come on and I did get a code for gross evaprotive emiisions leak. sounds ike the tech might have bunged up the install. I'll have to try decipher the location using the ETK. as a quick check, I removed the gas cap to check if I could hear/feel the vacuum but there was none. there's obviously a leak somewhere.
 
#5 · (Edited)
Terry Kennedy said:
Looks like it is part of the fuel system (Group 16). The full part name is "Leak Diagnosis Pump". I think it is the gizmo that turns on the Service Engine Soon light when you leave your gas cap off :D
Yep-- its the pump that pressurizes the fuel tank to check for leaks (for emissions compliance). Its located near the charcoal cannister which filters the vented air from the fuel tank. I believe its located underneath the car on the right next the spare tire well.

FYI-- here are the conditions necessary for the pump to operate:

The ECM only initiates a leak diagnosis test every second time the criteria are met.The criteria is as follows:
•Engine OFF with ignition switched OFF .
•Engine Contr l Module still in active state or what is known as "followup mode "(Main Relay energized,control module and DME components online for extended period after key off).
•Prior to Engine/Ignition switch OFF condition,vehicle must have been driven for a minimum of 20 minutes.
•Prior to minimum 20 minute drive,the vehicle must have been OFF for a minimum of 5 hours.
•Fuel Tank Capacity must be between 15 and 85% (safe approximation between 1/4 - 3/4 of a tank).
•Ambient Air Temperature between -7OC &35OC (20OF &95OF )
•Altitude <2500m (8,202 feet).
•Battery V ltage between 11.5 and 14.5 Volts
 
#6 ·
robg said:
Yep-- its the pump that pressurizes the fuel tank to check for leaks (for emissions compliance). Its located near the charcoal cannister which filters the vented air from the fuel tank. I believe its located underneath the car on the right next the spare tire well.
I'll have to look around for it. here's a pic. The pump is part number 20 in the below image.
 

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#7 ·
Is this the pump that..

Does this pump emit a "hissing" sound from under (behind) the car when turning the key to position "II" ?

I'm just wondering because my car has (for a couple of months now) come up with a really, really loud hissing sound while running. You can't really hear it inside that well but quite many people are asking me what's up with my car since there's a hideous hissing coming out from its rear.

It seems to be the same sound.. the people at BMW told me the hissing is normal if it is the same as what the "fuel pump" makes.. However, my friend's 330Ci (mine's a 330Ci -02 too) doesn't have this sound..not even half as loud.

Wonder if I need to show the BMW service people that bulletin number..
 
#8 ·
Axcu said:
Does this pump emit a "hissing" sound from under (behind) the car when turning the key to position "II" ?

I'm just wondering because my car has (for a couple of months now) come up with a really, really loud hissing sound while running. You can't really hear it inside that well but quite many people are asking me what's up with my car since there's a hideous hissing coming out from its rear.

It seems to be the same sound.. the people at BMW told me the hissing is normal if it is the same as what the "fuel pump" makes.. However, my friend's 330Ci (mine's a 330Ci -02 too) doesn't have this sound..not even half as loud.

Wonder if I need to show the BMW service people that bulletin number..
No, if you read my post above, you'll see that this diagnosis pump only runs when the key is off after atleast a 20 minute drive. The hissing sound I think you're referring to is indeed the fuel pump. I've noticed that many 01+ cars have very loud fuel pumps (inclduning my 325i). It is really annoying-- i odn't know why bmw can't fix this.
 
#9 ·
robg said:
FYI-- here are the conditions necessary for the pump to operate:

The ECM only initiates a leak diagnosis test every second time the criteria are met.The criteria is as follows:
•Engine OFF with ignition switched OFF .
•Engine Contr l Module still in active state or what is known as "followup mode "(Main Relay energized,control module and DME components online for extended period after key off).
•Prior to Engine/Ignition switch OFF condition,vehicle must have been driven for a minimum of 20 minutes.
•Prior to minimum 20 minute drive,the vehicle must have been OFF for a minimum of 5 hours.
•Fuel Tank Capacity must be between 15 and 85% (safe approximation between 1/4 - 3/4 of a tank).
•Ambient Air Temperature between -7OC &35OC (20OF &95OF )
•Altitude <2500m (8,202 feet).
•Battery V ltage between 11.5 and 14.5 Volts
That's a fascinating list - where did you find it? That would seem to explain why I didn't get the check light when I left the gas cap off during part of a cross-country drive - I didn't meet the "off for 5 hours" part.
 
#10 · (Edited)
Terry Kennedy said:
That's a fascinating list - where did you find it? That would seem to explain why I didn't get the check light when I left the gas cap off during part of a cross-country drive - I didn't meet the "off for 5 hours" part.
From the book2 of the e46 engine management training document. I downloaded it (and many other goodies) when I signed up for 24 hours of access to bmwtis.com. There's a lot of fascinating trivia like that in these training documents. I consider them to be the " real owners manual" for my car. :D Anyway-- I HIGHLY recommned you try it out-- $20 for 24 hours of access.

OH-- and later cars (ones that have the "check filller cap") light it when the leak diagnosis algorithm detects a large leak following a rise in fuel level.

I think it also explains why the check-engine light appears "random"-- you'd expect it to come on immediately following a fill-up if you left the gas tank cap loose-- when in fact you'ld have to drive enough to deplete 15% of the fuel, and then leave it parked for 5 or more hours--so usually it won't come on for a few more days.
 
#11 ·
after having this part replaced, my car was throwing code P0455 (gross leak in evaporative system. turns out that the tech forgot to install the rubber coupler pictured in the diagram above as part number 25. it doesn't seem like a part that is easy to overlook in my opinion. anyway, as the code stated, it created a gross leak in the evaporative system.
 
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