Boost pressure control valve/n75
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Bollocks I only just out all that back together 6 months ago.surely there's a way just for a boost pressure sensor .ffs
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Bizarrely, the IETIS circuit diagram index only makes reference to there being a Bank 2 device, and makes no mention of Bank 1, but a word search shows up both, which for RHD are C00674 Bank 1 N75 and C00675 Bank 2 N272.
It's located half way along the left (when sitting in driver's seat) side of the block, and is hanging off a loom that goes forward alongside the outer face of the head, then down the front left hand corner of the block, before heading aft again half way down the block.
(Sorry for the editing: I suspect that there's a typo, or two, in IETIS)
It's located half way along the left (when sitting in driver's seat) side of the block, and is hanging off a loom that goes forward alongside the outer face of the head, then down the front left hand corner of the block, before heading aft again half way down the block.
(Sorry for the editing: I suspect that there's a typo, or two, in IETIS)
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I'm not trying to be pedantic, honest I'm not, but as per the title of this thread, N75/N272 is not a sensor, it's actually a simple solenoid valve.
According to IETIS, there are two the same, with part number 037906283C.
Just to be perverse, on the circuit diagrams they are referred to as "Boost Control Valve" with reference N75 and N272,
However, in the Parts Catalogue two things are shown:
The first, termed "Electric Switch - Solenoid - Turbocharger Wastegate Bypass Control LH/RH" (with absolutely no mention of their reference numbers) having the part number 037906283C of which there are two off.
These are a simple two air port valve.
The second, termed “Assy Solenoid – Turbocharger Dump Valve RH Bank 1” and “Assy Solenoid – Turbocharger Dump Valve LH Bank 2” having parts numbers 3W0906283B and 3W0906283A respectively.
These are a more complex three way valve.
What I can't figure out is which of the two types is N75/N272
The C suffix part is used all over the VW/Audi product range, so take your pick of the normal suspects, including Autodoc who show seven different makes in stock.
They're also on AliExpress for a tenner.
Alternatively it might be worth giving your local TPS branch a call to get a price on a genuine one…
The Bentley part number versions are a different matter – they’re on Flying Spares at £95 each!
The photograph shows that they’re made by Pierburg, so I wonder where else they’re used…
Once you find them on your car, can you get the part numbers off the old ones so that we can do some searching, please?
Edited to add: There's a 2009 Pierburg catalogue here: https://www.romnes.no/site/content/d...urg%202009.pdf which contains a lot of similar three way valves.
I suspect that the Bentley version is simply a VW part (for example 7.22687.01.0) with a different mounting arrangement, but once you've got the old one in your hand you'll be able to see.
According to IETIS, there are two the same, with part number 037906283C.
Just to be perverse, on the circuit diagrams they are referred to as "Boost Control Valve" with reference N75 and N272,
However, in the Parts Catalogue two things are shown:
The first, termed "Electric Switch - Solenoid - Turbocharger Wastegate Bypass Control LH/RH" (with absolutely no mention of their reference numbers) having the part number 037906283C of which there are two off.
These are a simple two air port valve.
The second, termed “Assy Solenoid – Turbocharger Dump Valve RH Bank 1” and “Assy Solenoid – Turbocharger Dump Valve LH Bank 2” having parts numbers 3W0906283B and 3W0906283A respectively.
These are a more complex three way valve.
What I can't figure out is which of the two types is N75/N272
The C suffix part is used all over the VW/Audi product range, so take your pick of the normal suspects, including Autodoc who show seven different makes in stock.
They're also on AliExpress for a tenner.
Alternatively it might be worth giving your local TPS branch a call to get a price on a genuine one…
The Bentley part number versions are a different matter – they’re on Flying Spares at £95 each!
The photograph shows that they’re made by Pierburg, so I wonder where else they’re used…
Once you find them on your car, can you get the part numbers off the old ones so that we can do some searching, please?
Edited to add: There's a 2009 Pierburg catalogue here: https://www.romnes.no/site/content/d...urg%202009.pdf which contains a lot of similar three way valves.
I suspect that the Bentley version is simply a VW part (for example 7.22687.01.0) with a different mounting arrangement, but once you've got the old one in your hand you'll be able to see.
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@Yoghurtshotgun, did you end up finding and replacing this/these?
I'm getting a turbocharger boost control fault and have just checked the vacuum lines AGAIN with no leaks there.
Thanks,
Ron
I'm getting a turbocharger boost control fault and have just checked the vacuum lines AGAIN with no leaks there.
Thanks,
Ron
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Joined: Feb 2018
Posts: 862
Rep Power: 53
@Yoghurtshotgun, did you end up finding and replacing this/these?
I'm getting a turbocharger boost control fault and have just checked the vacuum lines AGAIN with no leaks there.
Thanks,
Ron
I'm getting a turbocharger boost control fault and have just checked the vacuum lines AGAIN with no leaks there.
Thanks,
Ron
The first photograph is bank (1) passenger side USA : "n75". Located above the alternator behind the front bumper cover. The bank (2) "n75" is buried on the driver's side. BTW, Bentley uses a different designation than N75 but the same component for reference.
The passenger side USA is accessible from the front of the vehicle. The driver's side looks like engine out, unless there is a secret.
This solenoid is positive pressure activated and isn't plumbed to the miscellaneous lines that were tested
The second photograph illustrates the N75 layout on a passenger side bank1 turbo. Upper right part with an open line.
Please post the DTC code.
Last edited by 1eapplebaum; Oct 12, 2022 at 11:05 AM.
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From: float: CH/AT/CZ/PL
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yeah... so i got this too...
made rather longer travel few days ago - at - pl - pl - at, about 1800km... (900km in a one shot, 90% highways with highways speed)
and half way on traveling back the CHECK ENGINE showed up,
after scan - the following was found:Address 01: Engine Labels: 07C-906-018-BEB1.clb
16627 - Solenoid Valve for Boost Pressure Control (N75)
P0243 - 004 - Malfunction - Intermittent - MIL ON
Readiness: 0000 1000after clear - few minutes later, when I did strong acceleration, CHECK ENGINE came back, with the same error.
cleared again and it came back again after acceleration - so was and is reoccuring all the time on acceleration.
I dont see or feel any symptoms of weak turbo, weak acceleration etc, car runs as it should, the CHECK ENGINE is the only signal that smth is wrong.
To add, Ive also have autel-scanner and autel reports it as "16627 - short to ground or implausible signal" as I remember.
Ive finished the travel with the CHECKENGINE, and just wondering now... questions below:
1. if all is ok from symptoms point of view, do I need to fix this asap or can drive for some time - wanted to wait till late autumn when i will garage my car for season and then i am going to eventually start playing with it?
2. what to fix (n75 solenoid replacement or other stuff to check and replace? maybe it is not malfunction n75, maybe something else is causing this error - wiring? plugs? how to check n75 on bench?)
3. i assume this is the sensor somewhere above alternator, so no need the engine out? am i right? I am asking because smb told there is another solenoid of the same role somewhere on driver side and this requires engine out. I hope the error is unambigous - if it is n75 then it is the one above alternator, dot?
4. is there any chance to replace the sensor without putting whole front out? maybe smb found a trick??? any custom tool to build to get there and replace n75 without many elements disasembling etc?
5. is this bentley specific solenoid? or can find any VW replacement??? pls point me to any aftermarket or vw xref if possible.
thanks in advance dear friends sharing the same challenges with this great car
made rather longer travel few days ago - at - pl - pl - at, about 1800km... (900km in a one shot, 90% highways with highways speed)
and half way on traveling back the CHECK ENGINE showed up,
after scan - the following was found:Address 01: Engine Labels: 07C-906-018-BEB1.clb
16627 - Solenoid Valve for Boost Pressure Control (N75)
P0243 - 004 - Malfunction - Intermittent - MIL ON
Readiness: 0000 1000after clear - few minutes later, when I did strong acceleration, CHECK ENGINE came back, with the same error.
cleared again and it came back again after acceleration - so was and is reoccuring all the time on acceleration.
I dont see or feel any symptoms of weak turbo, weak acceleration etc, car runs as it should, the CHECK ENGINE is the only signal that smth is wrong.
To add, Ive also have autel-scanner and autel reports it as "16627 - short to ground or implausible signal" as I remember.
Ive finished the travel with the CHECKENGINE, and just wondering now... questions below:
1. if all is ok from symptoms point of view, do I need to fix this asap or can drive for some time - wanted to wait till late autumn when i will garage my car for season and then i am going to eventually start playing with it?
2. what to fix (n75 solenoid replacement or other stuff to check and replace? maybe it is not malfunction n75, maybe something else is causing this error - wiring? plugs? how to check n75 on bench?)
3. i assume this is the sensor somewhere above alternator, so no need the engine out? am i right? I am asking because smb told there is another solenoid of the same role somewhere on driver side and this requires engine out. I hope the error is unambigous - if it is n75 then it is the one above alternator, dot?
4. is there any chance to replace the sensor without putting whole front out? maybe smb found a trick??? any custom tool to build to get there and replace n75 without many elements disasembling etc?
5. is this bentley specific solenoid? or can find any VW replacement??? pls point me to any aftermarket or vw xref if possible.
thanks in advance dear friends sharing the same challenges with this great car
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Joined: Feb 2018
Posts: 862
Rep Power: 53
The N75 "probably" isn't bad. The fault in this situation is likely a leak in one of the reference vacuum/boost lines behind the engine....smoke test recommended. [The n75 only sees boost directly from the turbo]. Somewhere a boost leak is initiating a fault code as an Implausible reference.
No shortcuts on N75 replacememt...bumper off on the right and engine out on the left. Don't rush into this yet The same N75 is used on many turbo diesel VAG cars at a fraction of the B tax.
Try live (data logging) boost with VCDS...you will also have to access bank 2 through 011 engine address.
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Posts: 524
From: float: CH/AT/CZ/PL
Rep Power: 34
The N75 "probably" isn't bad. The fault in this situation is likely a leak in one of the reference vacuum/boost lines behind the engine....smoke test recommended. [The n75 only sees boost directly from the turbo]. Somewhere a boost leak is initiating a fault code as an Implausible reference.
No shortcuts on N75 replacememt...bumper off on the right and engine out on the left. Don't rush into this yet The same N75 is used on many turbo diesel VAG cars at a fraction of the B tax.
Try live (data logging) boost with VCDS...you will also have to access bank 2 through 011 engine address.
No shortcuts on N75 replacememt...bumper off on the right and engine out on the left. Don't rush into this yet The same N75 is used on many turbo diesel VAG cars at a fraction of the B tax.
Try live (data logging) boost with VCDS...you will also have to access bank 2 through 011 engine address.
thank you very much @1eapplebaum
this is concerning... vacuum leaks - my car has 150kkm+ so for sure it was fixed in the past by previous owner (not me) hearing the leaks are showing even after only 16kkm so i assume it could not survive till now.
just to be clear - i have only this dtc issue, nothing physical - like weakeness or bad acceleration or rough idle. just this annoying dtc with mil on.
on the diagrams i find n75 only on the front of engine above alternator - no n75 on the other side.
any instructions how to test n75 on the bench? to nake sure it is really n75 malfunction?
you said i should do vcds logging on addr 1 and 11, you remember what measuring blocks to check (nimbers)? i will try to find on my own anyway but if you know already pls share - appreciate it in adv.
thanks again!
Registered User
Joined: Feb 2018
Posts: 862
Rep Power: 53
thank you very much @1eapplebaum
this is concerning... vacuum leaks - my car has 150kkm+ so for sure it was fixed in the past by previous owner (not me) hearing the leaks are showing even after only 16kkm so i assume it could not survive till now.
just to be clear - i have only this dtc issue, nothing physical - like weakeness or bad acceleration or rough idle. just this annoying dtc with mil on.
on the diagrams i find n75 only on the front of engine above alternator - no n75 on the other side.
any instructions how to test n75 on the bench? to nake sure it is really n75 malfunction?
you said i should do vcds logging on addr 1 and 11, you remember what measuring blocks to check (nimbers)? i will try to find on my own anyway but if you know already pls share - appreciate it in adv.
thanks again!
this is concerning... vacuum leaks - my car has 150kkm+ so for sure it was fixed in the past by previous owner (not me) hearing the leaks are showing even after only 16kkm so i assume it could not survive till now.
just to be clear - i have only this dtc issue, nothing physical - like weakeness or bad acceleration or rough idle. just this annoying dtc with mil on.
on the diagrams i find n75 only on the front of engine above alternator - no n75 on the other side.
any instructions how to test n75 on the bench? to nake sure it is really n75 malfunction?
you said i should do vcds logging on addr 1 and 11, you remember what measuring blocks to check (nimbers)? i will try to find on my own anyway but if you know already pls share - appreciate it in adv.
thanks again!
Hello sazam,
The address is between 114 -118...it's been awhile since I did this. You can graph the turbos against the ecu provided boost compared to the requested boost in one of the addresses.
The above process of data logging is the same as the VW/Audi turbo diesels...so go to those forums.
Bentley doesn't use the term N75 for the boost solenoids instead they call them N272 and N274 if I remember correctly. The part is the same for all three. Yes the left turbo has one to control the wate gate.
"N75" is the upper right solenoid with stainless steel tubes attached.
I think you're "N75" solenoids are good. The data logging will confirm and please post the results. So you have a small leak, a pinched line or an incorrect attachment somewhere. The ECU is seeing a deviation of boost flow through the system not enough to effect performance.