N75 valve question

What are some symptoms of a faulty N75 valve?

I still am having trouble with limps. It seems to be worse with cruise like descending a hill and starting up the next hill and about part way up and then derates. It seems to me it is something to do with the turbo upgrade acts like it building boost fast enough. Is it a mechanical failure or a tuning failure?

CarlosVW said:

What are some symptoms of a faulty N75 valve?

I still am having trouble with limps. It seems to be worse with cruise like descending a hill and starting up the next hill and about part way up and then derates. It seems to me it is something to do with the turbo upgrade acts like it building boost fast enough. Is it a mechanical failure or a tuning failure?

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Need to run some VCDS logs to know. If you went through a dealer for your tune I recommend contacting them for guidance. If not, drop me an email (click on my logo in my sig and then "Contact") and I will help guide you.

When was the last time you changed your fuel filter? I had the decelerate on hills problem when I was running around Indiana a while back. Changing the fuel filter cleared up that problem.

Find someone who has VCDS and can do a scan for you. If it is going into limp mode there is a code stored even if you don't get a CEL. If you can't find VCDS locally, any auto parts store can do a generic OBDII scan for you. Post the codes here.

I have an RC2 tune on my Passat and had a rash of limp episodes. Jeff suggested that it might be a dirty EGR Valve so we put a temporary block-off plate in and the problem went away. I cleaned the EGR Valve and took out the plate and haven't had the problem since.

Ok, I got a VCDS and the code is a P0299.

My fuel filter has roughly 5-6k on it.


I have Mark Malone doing my tuning and right now I got tune slightly more than his stage 2. The over all summary is that my BV43A is responding slow.

Same code that I was seeing. As I said, cleaning the EGR valve fixed it.

VCDS can do more than spit out trouble codes. One can easily compare the boost ECU is asking for vs. what it delivers with N75 duty cycle showing the ECU's effort to try and make the two match. Very telling data about the turbo and the system controlling it.

I offered to help as a courtesy because you are a Malone Tuning customer already, not to try and win your business away. It was an offer of service after the sale as an act of good will even though you didn't buy your Malone tune from me. Mark gives me excellent support as one of his dealers, I like to return the favor whenever I can.

Anyway, back to regularly scheduled programming...

It seems that this is a tune issue, regardless of whether if it is Malone or RocketChip. The tune changes the parameters of acceptable "control ranges" and when those parameters are not met, the ECU dumps it into limp mode. Jeff pointed me in that direction, I cleaned the EGR, and I have not have one limp mode episode since then. If it does reoccur, however, I will probably relocate the EGR.

Mark Malone has fixed my limp problem with his tuning. Thanks for your help.