PLC fails to enter emergency mode

Hello,

I have a one-bedroom apartment.


"After I was unsuccessful in increasing the boost pressure by adjusting a resistor in the control unit, I took it for a test drive yesterday without the pressure hose connected to the control unit. Normally, it should immediately go into limp mode, right?"
"But I didn't experience anything like that. I was able to drive normally, and I just kept an eye on the LD display so I wouldn't damage the turbo."
The car had plenty of power and ran perfectly, but I just couldn't give it full throttle...

Is this now considered normal behavior for older TDI engines, or is it not?


Best regards,
cksIT

Hi,
It's unclear where and how you took the test drive.
The anti-slip function (ASR) didn't activate until around 80 km/h, even though there was a weasel bite in the pressure hose leading to the control unit. Before that, it worked perfectly fine, even with full acceleration. That's why the damage caused by the weasel wasn't immediately obvious in the city.

Best regards,
Karsten.

Okay, I can also tell you that it takes quite a significant amount of unmetered air for the engine control unit (ECU) to go into limp mode. In my case, it only went into limp mode after a leak that was about three-quarters the size of the diameter of the turbocharger intake pipe. And even then, it only happened with a few seconds of full throttle – not even with a short burst of full throttle.

"No, I drove with the control unit without the hose connected, so there was boost pressure."
I was also driving around 80 km/h, I just fully accelerated and then took my foot off the accelerator slightly to avoid over-revving the engine.
Does the 1Z system go into emergency mode in such situations?
"Or could there be something wrong with my engine control unit (ECU)? That would also explain why I can't increase the boost pressure..."