No boost problem with N75

KingDragon

Pushing the Edge
Sep 11, 2001
88
0
Athens, Greece
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Running Revo2 on MK3 Cupra

It all started when suddenly I loost boost (boosting until 0.5bar)
I plugged in VAG-COM and got error
17956 - Boost Pressure Regulation Valve (N75): Open Circuit
My thought was to replace the N75 with a new one (N75J as my previous one).
I replaced it and also clear the DTC error and i got my boost back.

But now the same problem pops up (sometimes the check engine light comes on and sometimes no. But the problem is that sometimes i have BOOST (1.5bar) and sometimes NO! (and the checkengine llight does not pop up, but the error is still the same 17956.

What is the problem? It is wierd that sometimes i have boost and sometimes no. What should I do? I replaced N75 twice. Is there a procedure i should follow?

Thanks
 
Jan 8, 2007
2,958
1
Wiltshire
Don't take this the wrong way, but are you sure it's all plumbed in correctly?

Also check all surrounding vac hoses for leaks/kinks/splits as a starting point
 
There was a thread about this ages and ages ago -- previous owner of my car had the problem. They had suspicions of the oem TIP collapsing under high boost I'm sure -- there was a video of it floating around somewhere. Do you have an uprated TIP?

Only a suggestion because the guy changed the N75 about 3-4times to different variants and never solved the problem.
 

GarryGti

TurboLag is ur head start
May 1, 2008
338
0
Skagdover, Hampshire
I had this problem check your vac pipe to dv for them collapsing under high pressure and then disconnect your battery for a while.

thats what i did and it sorted it. no engine lights and it holds boost.
 
Dec 3, 2007
2,475
0
cardiff
The problem that i have no boost is bacause of the N75 issue, thats why i also get error 17956 (even with new DV).
I dont think that DV or TIP would generate such an error in VAG-COM.

When you had those problem did you also get this error?


sorry to go off topic but how did you get ur signature that long?
 
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