Sensitive Turbo: Cold Weather Issues?

Hello,
ich hab seit ca 1 Jahr einen Polo 9N mit ATD Motor 100PS PD. Year of manufacture: 2002.
"During the winter, this device would occasionally switch into emergency mode, and the following error code would appear in the error memory:"
1 Fault Found:
17964 - Charge Pressure Control: Negative Deviation.
P1556 - 35-10 - - - Intermittent

Unfortunately, I was never able to log the error when it occurred because it happened rather sporadically.

Based on my observations, the issue typically occurs when the outside temperature is below 5°C and the engine is still cold, below 90°C, at approximately 2000 rpm.

Based on what I've read so far about turbo problems, it seems to me that the issue could be related to either the mass airflow sensor (MAF) or a sticking variable geometry turbo (VTG) turbo.
Since spring, the control unit has no longer been going into emergency mode, but the engine sometimes has less power available.
Today, I wanted to test the ease of operation of the turbocharger via the vacuum line, but unfortunately, I couldn't find it.
Can someone tell me where I can find the VTG turbo, the adjustment rod, and the vacuum hose?

Here's another log file from my test drive today:
/download.php?id=2121

I would really appreciate helpful tips thank you.

freakyC64 wrote:

Based on what I've read so far about turbo problems, it seems to me that the issue could be due to two things: either the mass airflow sensor (MAF) or a sticking variable geometry turbo (VTG) turbo. Here's another log file from my test drive today: /download.php?id=2121

Hi,

Your log (5th gear) seems to indicate a severely jammed VTG (Variable Torque Gear), and strangely, it's stuck somewhere in the middle position.
The LMM values look okay to me.

Quote:

Can anyone tell me where I can find the VTG turbo, the adjustment rod, and the vacuum hose?

Behind the engine, above the right drive shaft, you will find the charging reservoir with its rod (at the top) and hose (at the bottom).

You can also feel it from above, or use a small mirror and a flashlight to peek around the corner (you'll need to remove the engine cover for this).

Once you've found the can, immediately check if your VTG rod is actually at the closed stop position when idling. Otherwise, follow the articles by Rainer and Ulf about VTG. Then you'll know if that was the problem.

Best regards, Poldi.