engine fault code p1200 (boost control valve)

[4rings]

hi,

had the car serviced today and the code p1200 (boost control valve) came up. and at partial throttle i do have boost fluctuation at low revs.


where is the boost control valve?? is it an exspensive part from audi?? i will ring them monday but wnat to know if im going to have to be prepared when they tell me a price lol. i will have my own mechanic fit it.


thnaks, rob

 

[4rings]

anyone?

 

[spencer-s3]

Sounds like N249 valve, it's on top of your rocker cover mate

 

[<tuffty/>]

Just because the code came up don't jump to conclusions its faulty...

Get the car scanned with something other than a 'code reader'... something like VAGCOM/VCDS as this will give you more info on the actual fault code than a generic code reader...

17608/P1200/004608 - Ross-Tech Wiki

17608/P1200/004608 - Boost Pressure Control Valve (N249): Mechanical Malfunction

This code is thrown when the N249 can't control the DV and dump boost... sounds like its a prob with your DV and not your N249.... if you are getting a fluttering sound when you let off the throttle this can indicate a dodgy DV (assuming you have a std one and not a Forge or other aftermarket valve)

Not all fault codes are there to suggest the actual component is at fault... some (as in this case) are thrown through faults caused by other components... in this case as a DV is a purely mechanical device it cannot throw a fault code itself but the N249 that controls it throws a code to say it cannot do its intended task...

Fault codes can be vague so you have to think about why they are there...

<tuffty/>

 

[4rings]

ahh ok this is interesting as i have a forge split-r valve on there atm. i presume this is the culprit??

 

[4rings]

and its weird why on partial throttle only under say 2100rpm it dumps the boost and then boosts back up and its fine.

when u full throttle it its fine all the way through the rev range.

 

[<tuffty/>]

You may have another problem... the N249 is the ECU's control over boost pressure already in the system... if it isn't happy with something it can use the N249 to prematurely dump boost which might be what you are experiencing... the code is thrown (IIRC) when the ECU tries to use the N249 to dump boost while the engine is under boost and can't see the boost drop off enough in a timely fashion... it uses the MAP sensor on later cars to see boost...

Don't get me started on Split-R's... I am not a fan...

If the valve is not working properly then it could cause this issue... difficult to tell tbh, what remap do you have assuming the car is mapped?

<tuffty/>

 

[4rings]

i have a stage 1 remap done by amd in woking. i also have a new maf sensor on there which is about 3 months old. and a jextex open intake. ive rang audi and a boost control valve is £25 so will try that first and see what happens i guess. this could get exspensive. i can see it coming

 

[4rings]

and its only at really low revs. surely the boost shouldnt be coming on at all before 2100rpm??