Boost Pressure 0 - Troubleshooting?

Hello everyone,

'Since yesterday, I've been having a problem where no boost pressure is being generated.'
The inspection today revealed the following:
- All vacuum hoses are in good condition.
- VTG test performed using a large syringe. OK.
- Replaced the boost pressure control valve with the one used for the EGR system, but unfortunately, there was no improvement.

Beim Starten des Motors konnte ich beobachten, daß die VTG in die Position für max. Ladedruck gefahren wird, dort für ca. 1 Sekunde verharrt und dann schlagartig in die Stellung für min. Ladedruck works.
Wouldn't this suggest that the emergency mode is being activated because some signal appears implausible to the control unit? In any case, the preheating light isn't flashing, and the engine sounds healthy.

Unfortunately, I don't have a VAG-COM to read the error codes. Maybe someone in the Cologne area has one? Otherwise, I'll have to go to the dealership on Monday.
I'm at a loss...

zzzZZ wrote:

Beim Starten des Motors konnte ich beobachten, daß die VTG in die Position für max. Ladedruck gefahren wird, dort für ca. 1 Sekunde verharrt und dann schlagartig in die Stellung für min. Ladedruck works. Wouldn't this suggest the activation of the emergency mode because some signal appears implausible to the control unit? In any case, the preheating lamp is not flashing, and the engine sounds healthy.

Hi.

Spontaneously, I would also suspect something like that... and next, I would read (or have read) the error memory.

Is the engine somehow modified?

You can experience a similar emergency mode with the 1Z if you bypass the fuse for the cigarette lighter.

00schmu wrote:

With the 1Z, you can get a similar emergency mode if you bypass the fuse for the cigarette lighter.

Hi.

if it fails once and, among other things, supplies power to the boost pressure valve, it shouldn't activate briefly every time the engine starts, i.e., move the VTG.
... aside from the turbocharger question, specifically regarding the wastegate and variable geometry turbo (VTG).

Is the engine somehow tuned?

Yup is a box tuning feature that is integrated into the control unit and can be switched on or off. However, it doesn't matter whether it's activated or deactivated - it always exhibits the same behavior.
'Additionally, I've observed that when you turn the ignition key to the preheating position, wait for more than 5 seconds, and then start the engine, the VTG (Variable Turbine Geometry) doesn't move at all. It only moves when the engine is started directly.'
Now, we need to know what checks are performed before the actual start process.

zzzZZ wrote:

Yup, it's a box tuning solution that's integrated into the control unit and can be switched on or off. But it doesn't matter whether it's activated or deactivated - it always shows the same behavior.

Well... if "the box" interferes with the RWG check beyond the tolerance limits (e.g., by activating it too early), at least my AFN responds with a preheating indicator light flashing... and an error entry.
I don't know how it works with the ALH (my wife doesn't let me get involved with things like that regarding her Ibiza ).

Quote:

Additionally, I've observed that when you turn the ignition key to the preheating position, wait for > 5 seconds, and then start the engine, the VTG (Variable Turbine Geometry) doesn't move at all. It only moves when starting the engine directly.

Well, EDC, that (in detail) unknown entity .

Quote:

Now, we need to know which checks are performed before the actual start process.

Exactly - and to do that, one would probably have to break into Bosch...

But at least find out what the error codes indicate.

Hi,

The problem resolved itself for the time being.
After it kept bothering me on Sunday, I removed the control unit and took a look at the modifications, hoping to find any cold solder joints or similar issues on the additional cables. However, I couldn't find anything. Everything was perfectly soldered.
After I had put everything back together, the car started behaving normally again?!? I hope it stays that way. That's also why I haven't driven it to check for any error codes.
If the game starts again, I will get back to you.