A few VAG-COM errors...

[paradigm]

Hi guys,

I know I could search for each individual code and try and work out what they mean, but I'm in a huge hurry (car is meant to be getting traded in soon), and need to sort the following out ASAP:

5 Faults Found:
17608 - Boost Pressure Control Valve (N249): Mechanical Malfunction
P1200 - 35-00 - -
17544 - Fuel Trim: Bank 1 (Add): System too Lean
P1136 - 35-00 - -
16622 - Manifold Pressure / Boost Sensor (G31): Signal too High
P0238 - 35-00 - -
17705 - Pressure Drop between Turbo and Throttle Valve (check D.V.!)
P1297 - 35-00 - -
16490 - Manifold / Barometric Pressure Sensor (G71) / (F96): Implausible Signal
P0106 - 35-00 - -

Now, what is the N249, I hear it mentioned a lot, but don't actually know where it is in the engine bay, how much is it to replace (just the part), and does anyone know the VAG part number for it?

Fuel Trim: Bank 1? is this referring to the pressure in the rail, or the pressure for injector 1? If its the rail, would this indicate that the rail has a pressure leak, or that the fuel pump needs replacing?

Sensor G31, where is this, would this be caused by the next fault (pressure drop?), or would it more likely be a failed sensor?

Pressure drop between turbo and throttle, check DV. Well I've "checked" the DV, it isn't loose, I also get the same error if I use a forge 007p or the stock DV, so could something else be causing this (the N249 issue perhaps?)

The final error I assume is a sensor failure, which sensor would this be?

Any help is much appreciated guys, I'll owe you all big time after this!

 

[skahigh]

Does the car drive normally? If so why not trade it in as is and let the garage deal with it? That might seem harsh but it really is a case of buyer beware.

 

[paradigm]

Does the car drive normally? If so why not trade it in as is and let the garage deal with it? That might seem harsh but it really is a case of buyer beware.

No it doesn't, it is very hesitant on the throttle (ok when rolling and if you don't use WOT). It is driveable, and nothing sounds amiss until you try and plant the throttle pedal.

I'd rather get the problems fixed if possible, I'm honest like that

 

[paradigm]

Thinking about it, I shouldn't need to buy anything, I have a full engine + ancillaries sat here in the garage, and I've just found all the DV & attached pipework still intact (inc what I assume to be the N249).

 

[edmong]

I would have to say you have a boost leak and the codes point out the dv and surrounding hoses. Check all hoses for splits. How old is your 007p?

 

[paradigm]

I would have to say you have a boost leak and the codes point out the dv and surrounding hoses. Check all hoses for splits. How old is your 007p?

12 months ish old, but only been on the car for maybe 2 months, I reverted back to the stock DV.

As I say, fortunately I have all the boost hoses, so might just swap them all over.

 

[paradigm]

Well, I found a spilt hose between the N249 and the intake manifold, so now the car idles correctly, but is still hesitant under wide open throttle. It's definately down on power and not boosting properly.

I've checked all the major turbo pipework, no splits or cracks, so now I'm at a loss?

Any ideas?

 

[paradigm]

Just need to know where the G31 sensor is now, only fault I have left.

 

[Muttley]

G31 is in the aluminium pipe that connects the two intercoolers.

F96, the altitude or barometric pressure sensor, is integrated into the ECU.

 

[paradigm]

Are you sure, is it not in the top hose between the passenger side intercooler and the throttle body?

As I have found that this sensor is cracked (across the connector, and as such the connector wobbles around), so have a feeling that it might be this!

Part number: 038 906 051 D ?

If I unplug it, I don't get any more errors on the VAG-COM, but the G31 error changes to "open circuit", so can only assume that this is the G31 sensor.

 

[Muttley]

Sorry, misread the diagrams, it is as you say in the top pipe, from the intercooler to the throttle body/inlet manifold. There is only one other sensor in the pressure side of the inlet, the temperature sensor G42, and that's in the manifold itself.

 

[Lodgey180]

Are you sure, is it not in the top hose between the passenger side intercooler and the throttle body?

As I have found that this sensor is cracked (across the connector, and as such the connector wobbles around), so have a feeling that it might be this!

Part number: 038 906 051 D ?

If I unplug it, I don't get any more errors on the VAG-COM, but the G31 error changes to "open circuit", so can only assume that this is the G31 sensor.

part number 038 906 051 d comes back as your g31 fault
boost preasure sensor.. could have something to do with the n249 and dv faults

 

[paradigm]

part number 038 906 051 d comes back as your g31 fault
boost preasure sensor.. could have something to do with the n249 and dv faults

I've got all the other errors cleared (and staying cleared now), after finding a vac leak in the manifold (small pipe that goes between intake plenum and N249 had a split), and replacing the N249 with a spare one I had lying around.

As I say, the only error I have now is the G31 error, and given that the connector on the sensor appears loose (and the casing looks cracked), I'd say its a pretty sure thing for it to be a physical issue with the sensor.

At least, I hope so, given I've just ordered one (at £72!!!!).

Back on the Forge DV at the moment too.

 

[Lodgey180]

yeah it could be picking up a leak if its cracked

 

[paradigm]

Would this be causing my throttle hesitation on wide open throttle though?

It happens from idle, but not above 3,000RPM (although there is no hesitation above 3,000RPM the car is still evidently down on power).

What else could it be? I've changed the coil packs, changed the injectors, and changed the FPR.

 

[skahigh]

I'd have thought it could do. Is the error intermittent? Perhaps the crack is causing it to over read and cut boost without need to.

 

[paradigm]

The problem is consistent, cold, hot, first run or last run of the day. Always stuttery on WOT so long as the engine is less than 3,000RPM.

The crack is actually across the plug, so it wouldn't be causing an air leak, just means that the potential for the plug connections to be broken is high, infact I'd go as far as to say that the plug connections will most likely not be actually connected to the sensor internally.

 

[Gubien]

Is the problem fixed?

 

[James.Judd.1]

This is exactly what is happening to my car at the moment G31 falt that wont clear missfiring under 3k fine over 3k.. i know its an old thread but its so frustrating when people dont post up the solution.. i can only assume that the new g31 fixed the problem as it all went quiet after he ordered that.