# Boost pressure Vag-com fault /N249 fault: UPDATED



## mikesimbo (Aug 21, 2009)

Hi Guys,

*SEE MY UPDATE BELOW*

I've just got hold of a vagcom cable and scanned the engine as I'm still experiencing some boost troubles (doesn't seem to be much there!) even after I spent about £150 on diagnostics and pressure tests, and the only thing they found was a loose pipe that they replaced the jubilee clip on, and also fastened all of the other pipes.

However, as I said, I just scanned the engine wth vag-com and got an *N249 fault*. My pc battery ran out before I could save the log but do any of you have an idea what it is and what the N249 valve does, and whether replacing that will solve the problem?

Another little question about vag-com...how can you get the graph or something to long how much BHP she's outputting?

Cheers,
Mike.


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## mikesimbo (Aug 21, 2009)

No ideas?


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## ecko2702 (Jan 26, 2009)

The N249 valve controls the Diverter valve it tells it when to open and close. It's like a fail safe really. What variant of the TT do you have 180 or 225? The 180's N249 valve is by the dip stick under the inlet manifold. the 225's is located on/above the cam cover. Replacing it should sort you out if you got a fault for it.


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## mikesimbo (Aug 21, 2009)

Hi,

I'm getting these faults:

2 Faults Found:
17608 - Boost Pressure Control Valve (N249): Mechanical Malfunction
P1200 - 35-00 - -
17963 - Shareware Version. To Decode all DTCs
P1555 - 35-00 - Please Register/Activate
Readiness: 0000 0000

*And from the ross tech website:*
*17608*/P1200/004608 - Boost Pressure Control Valve (N249): Mechanical Malfunction 
Possible Symptoms 
Power Loss 
Possible Solutions 
Check Boost Pressure Control Valve (N249)

*17963*/P1555 - Boost Pressure Control: Upper Limit Exceeded 
Possible Symptoms 
Reduced power output 
Limp mode 
Possible Causes 
Boost Pressure too High 
Hoses/Pipes incorrect connected, disconnected, blocked or leaking 
Charger Pressure Control defective 
VNT (variable nozzle turbo): nozzles stuck 
Solenoid Valve for Boost Pressure Control (N75) defective 
Possible Solutions 
Check Hoses/Pipes to/between Components 
Check Solenoid Valve for Boost Pressure Control (N75) 
Check / Clean / Replace Charge Pressure Control 
Check / Clean mechanism for variable nozzles

Does anyone have an idea what I should be checking? Or should I just take it somewhere like star performance will they sort it?

By the way I logged this rmp and maf from vag com - can anyone decipher?

Engine RPM	Air Mass Flow	Throttle Opening	Ign. Timing

/min g/s	% °BTDC

4080	108.06	100	17.3
4480	114.08	100	21
4880	139.44	100	15
5280	159.58	100	13.5
5680	174.92	100	11.3
6000	185.92	63.1	2.3
5600	52	7.1	35.3
4760	133	100	21.8
4360	123.47	100	10.5
4520	106.39	31.4	8.3
4480	15.08	5.9	3.8
4040	10.97	6.7	3.8

Cheers,
Mike.


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## Nick225TT (Oct 13, 2004)

Replace the Valve, they aren't expensive - that would be my first step.

You need to log boost - demand and actual

P.S. MAF values look good.


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## ecko2702 (Jan 26, 2009)

yup it seems as your n249 is at fault. I do have one laying around from my TT if you want it it's yours


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## ecko2702 (Jan 26, 2009)

They are pretty much a dealer only item. I thought mine was faulty so I got one from a Golf and and put that it. Turns out there wasn't anything wrong.......ever. Never had any codes either but I still thought something was up. I have since swapped the valves a few times and it's still the same so they are both working. I don't want anything for the valve. Just pay postage.


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## Grahamstt (Jul 22, 2008)

Or you could try a n249 delete - posted elsewhere on the forum, something I havent tried so cant comment on the results
Cheers
Graham


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## TT51 (Feb 28, 2009)

Grahamstt said:


> Or you could try a n249 delete - posted elsewhere on the forum, something I havent tried so cant comment on the results
> Cheers
> Graham


+1

Give it a go as its free :wink:


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## mikesimbo (Aug 21, 2009)

*UPDATE:*

I took my TT to A4 Audi Specialists in Glasgow today as I was still getting the boost pressure exceeding maximum fault on vag-com, and also an intermittent N249 mechanical fault.

It turns out the guys I got to diagnose the problem at Lavender Motors in Haywards Heath, West Sussex, put a non-return valve back incorrectly when they re-assembled my vacuum system, causing the N249 fault, and also the over pressure as the diverter valve could not be controlled correctly! They also put some other pipes back in the wrong place, jamming them and crushing them behind some clips that keep the engine cover on! Can't believe it - don't use them!!

Here's a pic of what was causing the problem (the pic has it installed incorrectly - how they left it!)









If you have this fault and have had work done, check this valve and any like it to make sure they have been installed the correct way round!

Cheers for all of your help guys, Mike.


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## Grahamstt (Jul 22, 2008)

Thats not good is it :x 
At least its sorted  
Graham


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## tony_rigby_uk (Nov 27, 2008)

just strip the N249 out... no more fault codes... apparently it's a good mod to do...

i'm thinking of doing mine !!


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## mikesimbo (Aug 21, 2009)

PROBLEM SOLVED!

Eventually decided to buy a new N75 from Audi stealers (£70.31!!) and fitted it tonight - seems to have solved the problem and boost feels a lot more punchy :>

finally happy!! thanks everyone for your help / suggestions!!

Mike


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## Matt P (Jun 22, 2010)

Sorry to necro this thread, does anyone have a pic of the NRV referred to in the previous pic the CORRECT way round? i'm getting an intermittent N249 fault and just replaced my N249 with no resolve (and my N75) and am wondering if this is the same?


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## Matt P (Jun 22, 2010)

Never mind, found some and mine is on right


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