Turbo Overboost p0234

jwilds

New member
Joined
Sep 25, 2009
Location
Kingsville, Ont
TDI
2002 Jetta
I just fixed the intercooler pipe from the intercooler to the EGR valve. I also had a vacuum leak to the EGR Valve. Since I have done that, I am getting a P0234, turbo Overboost condition, and the car goes immediately into "limp mode". If I turn the car off and restart it while coasting, the problem usually resets istself . This condition normally happens while I am passing or reving about 4000 rpm and happens when the trans switches from 2nd to 3rd (automatic).

Sometimes it also happens when I am hwy driving and when I get to the off ramp and turn, I find that it has happened again.

This has gone on for years, but only once or twice a year. Since I have fixed the leak in the vac system and the intercooler pipe, it is now happening a couple few times a day.

Any suggestions.:( :(
 

Dana @ Ross-Tech

Well-known member
Joined
Sep 15, 2009
Location
USA
TDI
Dana Marie ;-)
You mentioned that you repaired a vacuum leak, are all of the hoses to and from the N75 okay? (Basically all of the hoses)
Is this a ALH in a Mk4 body?
Are you using VCDS? If so you should be able to run basic settings and check the N75 and waste gate.
 

jwilds

New member
Joined
Sep 25, 2009
Location
Kingsville, Ont
TDI
2002 Jetta
I'm a neebie
N75?
ALH or MK4 Body?
Waste Gate?

Car is a 2002 Jetta TDI 1.9L

I am using a basic ODB reader and reset, no diagnostics related to it.

There is a bit of gunk in the EGR but it is actuating freely.

As long as I am nice to the accelerator, all is fine but if I get a little aggessive, crap happens.
 

Dana @ Ross-Tech

Well-known member
Joined
Sep 15, 2009
Location
USA
TDI
Dana Marie ;-)
N75 is the Wastegate bypass regulator valve.

ALH is a very common engine used in 99-03 Jetta/Golf/Beetle in the NAR Tdi.
Your engine code is on the timing belt cover, on sticker in trunk, and possibly in owners manual / maintenance booklet.

A Mk4 is the platform / chassis of VW you own.
See this chart for a better description.
http://www.ross-tech.net/VCDS/download/VCDSCompatibilityCharts.pdf

Since you are only using a generic scan tool, there is little you can do except check faults.
I may recommend a fully functional tool such as VCDS found here.
http://www.ross-tech.com/

And a Bentley repair manual for the vehicle. There are several distributors outside of Ross-Tech. Although, there is a discount for registered users.
http://www.ross-tech.com/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=VW
 
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