# P0234 Leaving me stumped....



## Phasma (Jul 20, 2011)

So I've been having surging / limp mode issues ongoing for a few months now. The car is completely stock motor wise. After I purchased the car roughly 20k ago I was having similar issues and VW replaced the following parts:

Camshaft
Follower
DV
PCV

So it ran great for a while but Im running into the same issues again in regards to heavy surging in 5&6th gears on the highway, eventually sometimes sending me into limp. I changed my follower last week even though the one I pulled out seemed to be wearing correctly and had a few thousand left on it. Pump and cam looked fine as well. 

I finally threw a CEL this week and it's reading as a P0234. I pulled the PCV just to take a look around and see if it had blown again but it seems fine. 

WHATS NEXT!? 

Is it safe to say that this is indefinitely a N75 issue? Fuel Rail possibly? I dont have a VAGCOM and I want to avoid the dealer at all cost.

:beer::beer:


----------



## Phasma (Jul 20, 2011)

Bump, Can anyone shed some light?

After doing some daily research it seems like a failing N75 would cause an Underboost code, correct me if Im wrong.

I guess this feels more like fuel cuts to me - VERY similar if not the same feeling as when my PCV and DV needed to be replaced. I'm assuming this could be happening because of the following assuming I've replaced PCV and DV with newest revisions:

-LPFP
-FUEL FILTER
-HPFP Thrust Sensor

UGH I just want my car to be running right! 

:beer::beer:


----------



## TCFGLI08 (Apr 6, 2011)

Sounds like an over boost situation.
Has n75 been checked , could be wrong.
Boost frequency switch
Terry
PS Just read your post that's funny my thoughts
exactly.


----------



## Phasma (Jul 20, 2011)

TCFGLI08 said:


> Sounds like an over boost situation.
> Has n75 been checked , could be wrong.
> Boost frequency switch
> Terry
> ...


Thanks for the response, Im hoping its something as simple as the N75 and not an issue with my wastegate. 

Can you elaborate on the "boost frequency switch"? I haven't stumbled upon this part in my searchs. 

Also, does anyone know if they released new revisions to the N75?

:beer::beer:


----------



## TCFGLI08 (Apr 6, 2011)

That is what N75 really is.
If you could borrow a known working
one and try it to see if it cures your problem.
No risk.
Terry

CAREFUL IT BREAKS EASILY


----------



## Phasma (Jul 20, 2011)

TCFGLI08 said:


> That is what N75 really is.
> If you could borrow a known working
> one and try it to see if it cures your problem.
> No risk.
> ...


Ah Ok, thanks for clarifying. There are like 250 names for the N75 apparently. I guess I'll bite the bullet and head to the dealer for a scan - none of my friends have MKV's or a Vagcom for that matter.


----------



## Phasma (Jul 20, 2011)

Alright, FRUSTRATING update / Rant: 

I gave in and brought it to the dealer for a diagnosis scan since I don't have a VAGCOM. The tech was really cool, let me walk into the shop to check out what the problem was. He said the issue was with the "Wastegate Actuator" and proceeded to show me how oil seemed to be coming out of it.... 

I decided to bite the bullet and just have him replace it then since I JUST WANT THIS PROBLEM SOLVED. He takes it out for a ride and tells me its a totally different car so I pay up and leave. 

Car runs AWESOME! I have power back on the highway!! I was so happy despite spending almost $400 for the fix. 

Fast forward to this morning, I hop into the car after not driving it since I brought it home from the dealer. The car proceeds to drop into limp immediately after pulling onto the on ramp. 

:banghead::banghead::banghead::banghead::banghead::banghead::banghead::banghead::banghead: 

I turn the car off and on - limp goes away but its still surging like a BASTARD in high gears. GOD DAMNIT 

I've noticed something though, if I punch it in 6th initial boost hits HARDDD and then falls on its face. It seems to hit harder than normal boost would. I dont have a boost gauge yet but the motor is all stock. It threw a CEL on my way into work and I plan to hit up an auto store for a quick scan at lunch but itll probably be the P0234 again... 

If I'm not mistaken the "wastegate actuator" must be controlled by the N75.... 

UGHHH Im so tired of thisss :thumbdown::thumbdown::thumbdown:


----------



## BlueDevil504 (Jan 19, 2012)

*16618/P0234/000564 - Boost Pressure Regulation: Limit Exceeded (Overboost Condition) 
**Possible Symptoms* 
-Malfunction Indicator Light (MIL) ON 
-Boost Pressure too high 
-Reduced Power Output 
*Possible Causes* 
-Hoses incorrectly connected, disconnected, blocked or leaking 
-Boost Pressure Control Valve (N75) faulty 
-Boost Pressure Sensor (G31) faulty 
-Turbo Charger stuck/faulty 
*Possible Solutions* 
-Check Charge Pressure Control System 
-Perform Output Test (to check the Turbo Charger) 
-Perform Basic Setting (to check the Charge Pressure Control) 
-Perform Pressure Test to locate Leaks 
-Check/Replace Boost Pressure Control Valve (N75) 
-Check/Replace Boost Pressure Sensor (G31) 
-Check/Replace Turbo Charger 

I would go to the dealer and have them check or replace all of this


----------



## Phasma (Jul 20, 2011)

Thanks for the input! I think N75 / checking for boost leak is my next project. The only way to test for a bad N75 is pretty much running logs with Vagcom right? 

Do people usually have problems with their wastegate actuators? I know Forge makes a replacement but I assume those are for cars that are tuned..


----------



## Gogadgetgo (Mar 6, 2021)

I just recently had this same problem, but I was finally able to find the issue. My turbo waste gate actuator was the culprit. It had a hole on the side and was throwing the car on limp mode due to vaccum loss. Got the part replaced by a licence mechanic, cost me $500, but now it’s fixed. Works like a charm.


----------

