So heading home today and all of sudden car has loss of power, I'm assuming it's in limp mode though no light is up on the dash other than esp light which is likely that broken cable again. Recently I'd had issues with smoke and had it diagnosed as MAF which I changed yesterday for the haas one in Euro car parts (followed same fitment as oem one) and the code was sorted. Still a bit a of smoke but I put it down to what's in the system however as stated had this issue on way home. Got home plugged in code reader and get a p0299 turbocharger underboost error code. Knowing not enough about cars to play about with this and that can anyone help me? I was only able to change the maf by following pics on guide here and am not that clued up on what's what under the bonnet as such.

Edited 5 May, 201610 yr by markbob917

Anyone?

Likely to be a vacuum leak from N75 boost control valve, check all your vacuum lines, it's also possible that the turbo vanes are stuck or you have a boost leak.

So heading home today and all of sudden car has loss of power, I'm assuming it's in limp mode though no light is up on the dash other than esp light which is likely that broken cable again. Recently I'd had issues with smoke and had it diagnosed as MAF which I changed yesterday for the haas one in Euro car parts (followed same fitment as oem one) and the code was sorted. Still a bit a of smoke but I put it down to what's in the system however as stated had this issue on way home. Got home plugged in code reader and get a p0299 turbocharger underboost error code. Knowing not enough about cars to play about with this and that can anyone help me? I was only able to change the maf by following pics on guide here and am not that clued up on what's what under the bonnet as such.

 

ESP light - check you brake light switch!

Likely to be a vacuum leak from N75 boost control valve, check all your vacuum lines, it's also possible that the turbo vanes are stuck or you have a boost leak.

Where is that located? Anyone able to give a pic of location at all please? Cheers for reply

Where is that located? Anyone able to give a pic of location at all please? Cheers for reply

 

Follow the vacuum pipe down from the variable vane actuator on the turbo

I had the underboost code showing up about a year ago. Turned out to be collapsed vacuum pipes caused by a split EGR pipe. It was difficult to find as the pipes looked fine at first, but when turned over it was clearly visible.

It really helped logging the boost using VCDS-Lite for me, as I could see that the turbo was not being actuated at all from the requested boost vs actual boost, and the N75 duty cycle was well off.

The N75 is the squarish black box in the top left hand corner if you're looking from the front of the car. It has a few vacuum pipes coming out from one side of it.

Thanks for all the replies guys, finally found the issue which was the pipe coming from the turbo behind the block had a split in it. All replaced now and it's back to normal thankfully not the turbo which was a concern for a while

Just another question regarding the N75, on other cars the N75 looks to be something that can be cleaned whereas it doesn't look like its something that can be cleaned on this? Or if so is there a guide on here?

No the N75 (vac box) cant be cleaned on these, not without major work that isnt really needed i suppose. Its a sealed unit im afraid. 

Hello guy's , i'm new on this forum ( sorry about my english) , i was looking in the past 2 weeks on different forums but I couldn't find nothing.. Right i've got a passat cc 2010 170 bhp and the coil and engine management lights are on and i loss power. I went to a garage and after the check all the pipes and egr etc, they said is the turbo actuator( they change that) but still nothing, forgot to say that the error was p0299 underboost presurre turbo/superchager. The car is the same so i decide to go to vw dealer , there technician said the actuator was not adjust with the car and is gone now , they put new one , still my car si the same , they came now with ideea of new turbo. Can someone please help me because i don't know if i need to replace turbo. Thanks guys