Bypassed N249 Fault??

[A3 T]

Hi guys

I've fixed a couple of boost leaks but the car only boosts when it feels like it.

I'm suspecting the N75 to be at fault so gave it a quick scan and this showed up:

17608 - Boost Pressure Control Valve (N249): Mechanical Malfunction
P1200 - 35-10 - - - Intermittent


The thing is, bypassing the n249 was one of the first mods i did years ago and have never had a fault show up.

I'm hoping this is just a loose plug but thought i would mention it on here just in case i'm wrong.


What do you guys think?

 

[andrew_wright]

From here I can't see under the bonnet . Check cable/plug and go from there.

Sent from my Nexus 6 using Tapatalk

 

[<tuffty/>]

Just means the ECU tried to operate the DV via the N249 and didn't see the boost drop as quickly as its coded too... sometimes happens on mapped cars with the bypass done..

Clear the code and see if it comes back....

<tuffty/>

 

[<tuffty/>]

If it was unplugged it would throw an open circuit code

<tuffty/>

 

[A3 T]

From here I can't see under the bonnet . Check cable/plug and go from there.

Sent from my Nexus 6 using Tapatalk

Ok sarky

I thought i would ask in case something else is known to throw the same code.

Just means the ECU tried to operate the DV via the N249 and didn't see the boost drop as quickly as its coded too... sometimes happens on mapped cars with the bypass done..

Clear the code and see if it comes back....

<tuffty/>

Maybe its there from when i was trying to find the boost leaks.

If it was unplugged it would throw an open circuit code

<tuffty/>

Good point

While were on the subject...lol

The other fault i had was:

00856 - Radio Antenna
36-00 - Open Circuit


I think this one is the earth track on the aerials circuit board.

 

[S3Powerxz]

About n249 faulth malfunction i have same error since i deleted it. It's electrically connected. The car is running fine though. So i think this error won't affect performance.

 

[<tuffty/>]

About n249 faulth malfunction i have same error since i deleted it. It's electrically connected. The car is running fine though. So i think this error won't affect performance.

It doesn't affect performance....

N249 is one of the ECU's many systems to control the engine under certain conditions... doing a bypass does not mean that the ECU can't continue to protect the engine as it has other ways to do this (N75 cut, throttle cut etc) but all thats happened here is a condition was met in the ECU's software that made it decide to operate the N249 to open the DV using the vacuum store... when this happens the ECU expects to see a drop in pressure from teh MAP sensor in a specified time... as chances are it won't see this due to numerous factors the ECU assumes the DV is faulty and pops this code... the mechanical malfunction relates to the N249's function rather than the N249 itself...

The DV is not an electrical item so the ECU cannot see if its working or not... it has to rely on the result of its function and the sensors are used to back that assumption up..

TFSI's use an electrically operated DV which replaces the mechanical vac operated DV and the N249

<tuffty/>