I scanned a members car today which had an overboost and an EGR faults logged:

2 Faults Found:
000564 - Boost Pressure Regulation  
               P0234 - 000 - Limit Exceeded (Overboost Condition) - Intermittent
             Freeze Frame:
                    Fault Status: 00110000
                    Fault Priority: 0
                    Fault Frequency: 1
                    Reset counter: 255
                    Mileage: 209465 km
                    Time Indication: 0
                    Date: 2000.00.00
                    Time: 10:43:03
 
             Freeze Frame:
                    RPM: 3402 /min
                    Speed: 69.0 km/h
                    Load: 100.0 %
                    Voltage: 14.29 V
                    Bin. Bits: 11000000
                    Absolute Pres.: 2029.8 mbar
                    Absolute Pres.: 2499.0 mbar
 
001025 - EGR System  
               P0401 - 000 - Insufficient Flow - Intermittent
             Freeze Frame:
                    Fault Status: 00110000
                    Fault Priority: 0
                    Fault Frequency: 9
                    Reset counter: 255
                    Mileage: 209469 km
                    Time Indication: 0
                    Date: 2000.00.00
                    Time: 11:03:45
 
             Freeze Frame:
                    RPM: 1554 /min
                    Speed: 46.0 km/h
                    Load: 14.1 %
                    Duty Cycle: 14.6 %
                    Duty Cycle: 100.2 %
                    Mass Air / Rev.: 220.0 mg/str
                    Mass Air / Rev.: 440.0 mg/str
 
Readiness: 1 2 0 0 0

So we did a log of boost and to me it looks like the actual is running too high compared to the requested.  Below is a link to the log file and I would appreciate if someone what knows could have a look and see what they think

 

https://dl.dropboxusercontent.com/u/19442742/VCDS/LOG-01-001-011-003.CSV

 

 

 

Sounds like a sticky turbo to me

Sounds like a sticky turbo to me

 

That's what I was thinking.  It didn't go into limp whilst we were driving, but apparently it does when cold, but is OK when warm.  It's an ex ambulance service car which has done 130k.

 

Looking at the log file it seems to be overboosting but not quite enough to trigger a fault.

ive had same issues on my mk5 golf 2.0 tdi, even after fitting a recon turbo from reputable company, , new maf ect

 I had egr insufficient flow fault, so I had it mapped out altogether and it is blanked at exhaust manifold just to be certain lol

and my overboost was an chaffed wire in map sensor loom under airbox/fuseboard in engine bay, 

all ground points in car where oxidising up, so cleaned those and greased them to prevent further corrosion

I sorted that and was resolved temporarily,

overboost came back, 

till I also replaced the map sensor, now the faults are eradicated, and it boosts fantastic  and mpg back up to 50mpg, as I was down to 38mpg prior to resolving the troubles I mentioned

Edited 4 September, 20169 yr by moiloon