MK5 Golf GTI

All Things Mk5 => Mk5 General Area => Topic started by: Duffy on November 03, 2008, 12:14:36 pm

Title: Error codes
Post by: Duffy on November 03, 2008, 12:14:36 pm
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.
Title: Re: Error codes
Post by: neg on November 03, 2008, 01:05:29 pm
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?
Title: Re: Error codes
Post by: Duffy on November 03, 2008, 05:02:20 pm
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.

Title: Re: Error codes
Post by: Teutonic_Tamer on November 03, 2008, 05:16:22 pm
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?
Title: Re: Error codes
Post by: 182_blue on November 03, 2008, 05:21:13 pm
heres the wiki http://wiki.ross-tech.com/index.php/Category:Fault_Codes

cant seem to find the codes though ?
Title: Re: Error codes
Post by: Duffy on November 03, 2008, 05:26:26 pm
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.
Title: Re: Error codes
Post by: 182_blue on November 03, 2008, 05:29:08 pm
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
Title: Re: Error codes
Post by: Duffy on November 03, 2008, 05:34:48 pm
looooove it.

think the novelty may wear off after a few months.  :jumping:
Title: Re: Error codes
Post by: Teutonic_Tamer on November 03, 2008, 05:37:57 pm
hmm. i cant seem to find them either.

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

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.  :wink:  :smiley:
Title: Re: Error codes
Post by: Teutonic_Tamer on November 03, 2008, 05:45:54 pm
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!  :chicken:

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

Title: Re: Error codes
Post by: Duffy on November 03, 2008, 05:50:35 pm
hmm. i cant seem to find them either.

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

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.  :wink:  :smiley:


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.
Title: Re: Error codes
Post by: Duffy on November 03, 2008, 05:51:25 pm
i thought it was VAG-com as thats what they said they were going to hook it up to.

Will need to ask tomorrow.
Title: Re: Error codes
Post by: Teutonic_Tamer on November 03, 2008, 05:54:42 pm
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.
Title: Re: Error codes
Post by: Duffy on November 03, 2008, 05:56:52 pm
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
Title: Re: Error codes
Post by: vRStu on November 03, 2008, 07:21:44 pm
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

Title: Re: Error codes
Post by: Teutonic_Tamer on November 03, 2008, 07:29:56 pm
ah i see. That delay must cost performance time though yes?

Well, you will suffer a slight delay from a touch more turbo lag.

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

Functionwise - no.  Construction - yes.

The OEM one uses a rubber diaphragm, which is reported to be prone to tearing, but the latest releases of the OEM one seems to be more reliable.  Higher boosts from remaps seem to aggravate the life span.

An aftermarket one like the Forge uses a piston with O rings, and is considerably more durable, though still needs "servicing".  The Forge ones look  8)  8)  8)  8) though.  :wink:
Title: Re: Error codes
Post by: Teutonic_Tamer on November 03, 2008, 07:32:36 pm
How do you fit an R32 exhaust to a GTI?  CAT Back only?

Unless it is just the rear box - similar to the way RedRobin has the quad tips on his???


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

Yup, agreed.  But a correct log of the N75 should give a clearer diagnosis.
Title: Re: Error codes
Post by: vRStu on November 03, 2008, 07:45:42 pm
Is it also possible that some of those codes were already present from the Forge fitting?

Have you cleared them off and then checked again?
Title: Re: Error codes
Post by: 182_blue on November 03, 2008, 07:47:10 pm
Is it also possible that some of those codes were already present from the Forge fitting?

Have you cleared them off and then checked again?

i think so, he said "The last code didnt repeat but the top three did after being reset." , still not sure what program there using though
Title: Re: Error codes
Post by: Teutonic_Tamer on November 03, 2008, 07:54:29 pm
Is it also possible that some of those codes were already present from the Forge fitting?

Have you cleared them off and then checked again?

i think so, he said "The last code didnt repeat but the top three did after being reset." , still not sure what program there using though

I agree.

I have had a right nightmare with a £20k Snap-On reader (I think it was Solus) - utter shyte, and grossly over-rated.  Unfortunately, the collegue who owns it has it on the knock, so can't really get rid of it.  It reapeatedly gave the wrong codes on my last S4, failed to interrogate many of the modules, and completely missed a reading from the ESP ECU.

Unfortunately, many of these so called fault code readers, even the professional ones, don't actually read the manufacturer specific codes.  They only read the generic EOBD or OBD2 codes, which are just really basic codes.
Title: Re: Error codes
Post by: 182_blue on November 03, 2008, 07:56:15 pm
perhaps if we know where he is one of us will be able to get him hooked up with Vag com
Title: Re: Error codes
Post by: Teutonic_Tamer on November 03, 2008, 07:59:56 pm
perhaps if we know where he is one of us will be able to get him hooked up with Vag com

I think from his "welcome" thread, he stated he was from Scotland-shire!
Title: Re: Error codes
Post by: 182_blue on November 03, 2008, 08:03:19 pm
perhaps if we know where he is one of us will be able to get him hooked up with Vag com

I think from his "welcome" thread, he stated he was from Scotland-shire!

well, we must not hold it against him  :laugh: :laugh:
Title: Re: Error codes
Post by: Duffy on November 03, 2008, 08:04:45 pm
With regards the exhaust system, its and r32 Style system created by Milltek for the GTi. Its cat back yes but you can get a turbo back system from milltek aswell.

Im from not so sunny or warm glasgow. The place i go to is called Drivers ltd. There supposed to be best in the city and when i spoke to them said they were going to put it on the VAG-COM system.

Title: Re: Error codes
Post by: Duffy on November 03, 2008, 08:05:23 pm
perhaps if we know where he is one of us will be able to get him hooked up with Vag com

I think from his "welcome" thread, he stated he was from Scotland-shire!

well, we must not hold it against him  :laugh: :laugh:

 :jumping: Were not all crazy!!
Title: Re: Error codes
Post by: Teutonic_Tamer on November 03, 2008, 08:12:00 pm
perhaps if we know where he is one of us will be able to get him hooked up with Vag com

I think from his "welcome" thread, he stated he was from Scotland-shire!

well, we must not hold it against him  :laugh: :laugh:

 :jumping: Were not all crazy!!

Ahh, but do you have ginger hair and drink Special Brew - or is it McEwans?  :wink:  :evilgrin:  :evilgrin:  :evilgrin:  :evilgrin:
Title: Re: Error codes
Post by: Duffy on November 03, 2008, 08:31:41 pm
lol i do not have ginger hair nor drink that stuff. Truth be told after a holiday away i am not hooked on Corona. Random i know.