High Boost Pressure BKD: Causes & Solutions

Hello everyone,

I'm having a small problem with a Golf 5.

The car occasionally enters limp mode. Interestingly, this happens without the warning light illuminating or any other noticeable indications on the instrument cluster. When checked with the diagnostic tool (01), the only error code recorded is "boost pressure exceeded."

Please find attached 3 files.
1. Autoscan (yes, the mileage is correct).
2. 3-8-11 in 3rd gear, with the emergency system activated at just over 4000 RPM.
3. 3-8-11 im 4. Walking without a run.

Unfortunately, I don't know as much as I'd like to.
To me, it looks like a VTG clamp, but the AGR valve is also giving me some trouble...
Does the car have two problems?

Can the log file be used to identify the most likely cause of the error?

I read in the thread at /viewtopic.php?t=27741 that the hoses appear to be in good condition visually... Should I just replace them as a precaution?

Thank you very much for your help!

Marco.

(I'll be in the Netherlands this weekend and will probably be able to respond again on Sunday.)

Hello,

It's normal for the AGR (Abgasrückführung) valve not to operate at full throttle. However, your boost pressure control system is concerning: It's not just a minor issue, it seems to be permanently set to "high boost"! The diagnostic value of 2601 mbar (the maximum value for diagnostic readings in your system) is consistently displayed across almost the entire RPM range, which could quickly damage the turbocharger at higher RPMs (around 4000 rpm).

You should check...
- Whether the VTG (variable turbine geometry) is actually working or is "stuck". For example, by performing an actuator test via the engine control unit.
- Whether the vacuum system can be vented, meaning the canister on the charger can eventually close again, or whether the vacuum remains. -> Check for blockages in the ventilation system, and inspect the solenoid valve block.

Best regards, Rainer.

Hello,

If it really has 512,000 km on the clock, then it will probably need a new turbocharger... mine had the same issue at 190,000 km; ultimately, the variable turbine geometry (VTG) adjustment was stiff and was closing "too slowly."

Unfortunately, replacing the turbocharger on a Golf is a tricky job.

SG
Alevuz.