Error codes

[Duffy]

Big problems with my gti just now. if anyone can offer advice would be great. basically got an r32 milttek exhaust fitted along with a forge DV atmospheric dump valve around a month an a half ago.
The other day on the motorway felt a sudden loss of power and engine management light comes on. No dumping of air froom dump valve and feels lik im getting liittle or no boost from turbo. Take it to place got all work done and the comp reads following error codes:-
001092 - Evap Purge contnrol valve (N80) Circuit open
000579 - Solenoid Valve(a) for boost pressure control (N75) Malfunction
000051 - Turbocharger bypass control valve - open circuit
000256- Mass air flow sensor (G70) supply voltage.

The last code didnt repeat but the top three did after being reset. Called dealer and they ve said its the dump valve and to get it removed. but garage that carried out the work say it isnt the dump valve and the dealer are just saying this to void the warranty for this part.

Any advice / comments? im getting well annoyed, just want it all fixed.

[neg]

Must be a problem with the Forge one you have fitted.  Are you sure its been fitted correctly?  no leaks, loose connections etc.

The ECU thinks this is faulty/not working so will put you into limp mode which will feel like no turbo at all as it only boosts to 5psi.

When you say atmos valve, is this just the spacer on the OEM DV?

[Duffy]

i have absolutely no idea. The garage i got to fit it are really reputable in glasgow. on the receipt sheet it says 1 Forge Atmospheric Dump Valve - VW 2.0 T.

Any advice? the DV is getting removed tomorrow.

[Teutonic_Tamer]

I would personally ditch the atmospheric DV, and go for a total recirc DV - as the GTI was never designed to have an open vent for the turbo boost.

What is the battery voltage, because low voltage can give spurious readings on other unrelated sensors too.

Oh, and check any vacuum pipes for the inlet manifold, and look for damaged wiring too.

Finally, have you looked on the RossTech Wiki for further clues on the fault codes?

[182_blue]

heres the wiki http://wiki.ross-tech.com/index.php/Category:Fault_Codes

cant seem to find the codes though ?

[Duffy]

hmm. i cant seem to find them either.

Does the Recirc Valve have the same noise and job as the Atmospheric ?

Well annoyed, the car is like a shadow of itself performance wise.

[182_blue]

hmm. i cant seem to find them either.

Does the Recirc Valve have the same noise and job as the Atmospheric ?

Well annoyed, the car is like a shadow of itself performance wise.

do you like the phhsssssshhhh sound

[Duffy]

looooove it.

think the novelty may wear off after a few months. 

[Teutonic_Tamer]

hmm. i cant seem to find them either.

Quote from the Wiki - "Additional codes are beeing continously added." 

Does the Recirc Valve have the same noise and job as the Atmospheric ?

They both do the same job (well sort of), but they do it slightly differently, and can actually have very different effects on the actual driveabilty.  Basically, they both limit the upper level of turbo boost.  When actually operating by limiting boost, the standard recirc valve simply sends excess "air" back to the low pressure side of the turbo (this then keeps the turbo at maximum spool, therefore max efficiencey), whereas the atmospheric simply "dumps" the excess air into the atmosphere (this is then wasted, and will allow the turbo to slow dowm, creating a delay when boost is again requested).

So basically, if you want to sound like a Chav, and actually loose performance - keep the atmospheric DV.  But if you want the "mature" sound, and maintain max performance, then keep the OEM or aftermarket closed recirc valve.   

[Teutonic_Tamer]

What kind of codes are these - were they off VAG-COM, or some independent fault code reader?

Because from my tabels, using VAG codes - "00579 Knock Sensor Control - Cylinder 3" ????

And "01092 Convertible Top Open Position Switch -F171"

001092 - Evap Purge contnrol valve (N80) Circuit open
000579 - Solenoid Valve(a) for boost pressure control (N75) Malfunction
000051 - Turbocharger bypass control valve - open circuit
000256- Mass air flow sensor (G70) supply voltage.

I'm looking at other tables though . . . . confused! 

EDIT: I'm looking at a Bentley table, and they don't match that either!

EDIT2:  looking at a third source:

P0256 Injection Pump Fuel Metering Control "B" Malfunction (Cam/Rotor/Injector)

P0579 Cruise Control Related Malfunction

[Duffy]

hmm. i cant seem to find them either.

Quote from the Wiki - "Additional codes are beeing continously added." 

Does the Recirc Valve have the same noise and job as the Atmospheric ?

They both do the same job (well sort of), but they do it slightly differently, and can actually have very different effects on the actual driveabilty.  Basically, they both limit the upper level of turbo boost.  When actually operating by limiting boost, the standard recirc valve simply sends excess "air" back to the low pressure side of the turbo (this then keeps the turbo at maximum spool, therefore max efficiencey), whereas the atmospheric simply "dumps" the excess air into the atmosphere (this is then wasted, and will allow the turbo to slow dowm, creating a delay when boost is again requested).

So basically, if you want to sound like a Chav, and actually loose performance - keep the atmospheric DV.  But if you want the "mature" sound, and maintain max performance, then keep the OEM or aftermarket closed recirc valve.   

I have been llooking for a description like that for ageees. I didnt know that the Atmospheric DV lost you boost pressure and therefore performance. i thought if anything it helped protect the turbo from the air being pushed back in against it, my bad.

thanks for the advice. I shall get a recirc valve ordered tomorrow.

[Duffy]

i thought it was VAG-com as thats what they said they were going to hook it up to.

Will need to ask tomorrow.

[Teutonic_Tamer]

Duffy, the atmos DV won't actually loose any peak turbo boost, but what it does is allows the turbo to slow down too much.  Then when you get on the gas again, there is a delay in getting the boost again.

[Duffy]

ah i see. That delay must cost performance time though yes?

Is there any difference between an OEM recirc valve and an aftermarket one?

Thanks again

[vRStu]

How do you fit an R32 exhaust to a GTI?  CAT Back only?

I don't have time to pull up the CFD's at the moment but I don't suppose they are all on the same fuse are they?  That wiring seems to be all around the same place to me, wonder if the cable to the forge DV has been damaged/melted?

If indeed your car is a GTi then the Forge DV is doing the work of the Turbocharger bypass control valve, or not in your case