So is the turbo behaving as it should then? And something else (like a leak) is causing the underboost rather than a part of the turbo not responding correctly Like the actuator or waste gate for example?
Would sticky vanes show in that data ?
Well, wish I could say something for sure.
The confusing part is that the pressure build-up lags full time. I was a kind of expecting to see the pressure keep up with commanded value up to some point and then just flat out. So can't rule out sticky vanes yet I'm afraid.
For comparison below a plot of a working system - though a bi-turbo. The deviations/dips on specified values here are when foot is off the throttle - engine braking.
What is the valve that looks just like the n75 valve which is located right along side the n75 valve? Looks like two of them?
"Intake manifold flap air flow control valve - N316"
Wonder what it is and if we can test this with another live log ?
VCDS can run quite a few turbo related tests. Unfortunately I haven't tried them enough to understand what to get and how to interpret results.
VCDS > Engine > Output tests
Also under Basic Settings there are quite a few related tests. E.g. as below
VCDS > Engine > Basic settings
IDE00457-Test of turbocharger
IDE00459-Test of transfer fuel pump
IDE00460-Test of intake manifold runner flaps
IDE00891-Test of charge air pressure control
IDE07136-Test of wastegate actuator
IDE07464-Turbocharger recirculating valve test
IDE11075-Adaptation of turbocharger recirc. valve
NOTE: Probably prerarable to avoid running anything named as "reset" or "adaptation" as the result might be something not desirable.
To get ideas how to set up VCDS for testing e.g. below - of course the measurement values etc. need to adapt.
So it seems - inevitable P0401. Well, visited a VW garage to be tested - the van had accumulated 30 events in ECU's memory since July 2021 (since 20 months now). Eventually managed turn on the emission light at event number 31 - thus had a priviledge to have EGR flow tested. The result -...
www.t6forum.com
So, I've been getting the all too common P046C fault code along with P2457 (Insufficient EGR Cooling Performance). Neither alone will flag a check engine light but combined they sometimes seem to. To try to figure out what is going on, I ran an EGR Flow test on VCDS using instruction from @mmi...
www.t6forum.com
Wonder what it is and if we can test this with another live log ?
Let me look into my own logs...