17705 - Pressure Drop between Turbo and Throttle Valve (check D.V.!)

[bobbieboy69er]

Ive managed to get rid of this code by....  theres a metal to metal connection on the pipe between your DV and Pancake pipe (jack the car up ir stick it on the ramp as its inbetween the engine and the drivers footwell) with a metal U shape clip that holds it together.  When you get the extra boost usually from a map the clip weakens and the connection then leaks,  you can get a new clip for about £1 from VW and it fixes the problem. 

Well this worked for me anyway   

[paulturbo]

^when you got this code was it when you where at full throttle? after a few mins it would flat spot?well sort of?

[bobbieboy69er]

nah, it would just pop up now and again when i had a scan, but it could cause a flat spot due to leaking at high boost, mite b worth a data log between actual and requested boost!? See uf it drops off at high boost?

[Mertz]

I have a mark IV 1.8T AUM engine code and i have this loss of boost pressure problem so far i have changed the Y shapped pcv pipe at the top of the engine going from the cam case to the inlet and crankcase. i am about ot change the recirculatory dump valve as it is making a wooshing sound like a sh!tty atmospheric dump valve which would explain the fault code "loss of boost pressure between turbo and throttle valve". if this does not sort out the problem my next step is to change the PCV valve just bellow the inlet manifold as it is leaking oil and these are all problems common with the AUM engine. i am a master technician in my garage that i work for so would like to think i know what i am doing with cars. once i have curred my issues i shall report back as i am determind that this engine is not going to get the better off me ha ha ha!!!

[RTechUK]

The fault we are talking about happens when the car is cold first thing in the morning when cold, light throttle and bang limp mode with out even making any boost, key on off and then its fine for the rest of the day.

This is on remapped cars which are fine running the stock map but as soon as remapped triggers the bug in the software code, Stu had his car put back to stock where it cured the problem, but as soon as the map was on it was straight back, his tuner soon fixed the BUG and the car is now spot on.   We had the same issues on our Gen3 maps back about 5 years back, but since then all of our 1.8T DBW maps now carry the patch..

[Mertz]

If you have a non- recirculatory dump valve that will 100% be your problem as it needs the boost to be dumped back into the inlet other wise your in for a world of trouble

[RTechUK]

If you have a non- recirculatory dump valve that will 100% be your problem as it needs the boost to be dumped back into the inlet other wise your in for a world of trouble

Not for 17705?  The BOV brings up fuel faults ADD and MULT fuel trims.