Help With 2015 Tiguan - low throttle position and boost at high RPM

[5GChris]

Hoping someone here can help with a problem on my wife's car. I do some tuning on LS platform stuff, but never anything on VW so I am not familiar with what is "normal". I am just trying to troubleshoot our personal vehicle; 2015 Tiguan 2.0tsi.

It just started today and she complained it has no power. She said "It is like I lost my turbo". I immediately figured that was the case.

However, I did some datalogging and found that desired boost and boost pressure follow each other, but it is limited to around 3psi. I also found that when going to full throttle the throttle position flashes up to 100% and then immediately drops down to the 20-30% range and slowly increases to around 50% at 5500rpm. Timing is 15-20 under power and fuel trim is 10% or less, so I don't feel like I have a fuel delivery issue. It seems the PCM is reducing power for some reason.

Car has no power to accelerate but will rev to 5500RPM range. It also has no CEL. Car shifts normal for the RPM, but power is just greatly reduced.

I do have a datalog I could send if anyone could help.

Any help in what direction to look is greatly appreciated! 25-01-07 10-54-43.hpl

[aaronc7]

Looking at "log details", it does say: P0301 - Cylinder 1 Misfire Detected (Current).

[5GChris]

Looking at "log details", it does say: P0301 - Cylinder 1 Misfire Detected (Current).

I have had misfire codes in the past(before replacing plugs and coils) but never had the reduced power situation. It did do a couple of strange misfire type events at wide open throttle one time, but it was not on this log. Coils and plugs have less than 10k on them. Any other feedback on the misfire?

[aaronc7]

Nah, no other ideas. I'd be inclined to think something like, the WG actuator is out of range and putting the car into a limp mode of sorts. But I'd expect there to be a DTC/CEL for that. It's possible maybe that it's a VAG specific DTC and hptuners can't see it AND it's one that won't illuminate the CEL? Seems unlikely to give you the CEL though if it's causing limp mode and doesn't have a corresponding universal DTC that any reader can see.

Without a code it's definitely hard to get started