Emergency Mode at 160

Hello,

I'm participating for the first time today, and I hope you can help me.
I have an Audi A4 Avant 1.9 TDI 90 hp AHU, manufactured in 1997. The following problem occurs with this vehicle:

- The vehicle struggled and barely managed to travel 170 meters downhill with a tailwind.

So, I thought I would get a chip tuning done to get a little more performance out of the car.

Once the chip was installed, and I, of course, wanted to test it immediately, I noticed that when I accelerated to full throttle, ...

- At 160 km/h, the engine immediately loses power (goes into limp mode), but power returns later.

ich auf dem Gas stehen bleibe. Maximum speed: 180.

However, it doesn't happen quickly; it's a slow process.

What could that be?

Mass airflow sensor?, EGR valve?, Pressure hose?, Pressure sensor?, Chip?, Throttle position sensor?, Turbocharger?, Wastegate?, Oil sludge in the intercooler?, etc.

Please help me .

The people at Audi don't seem to know what they're doing, and they want to keep my car for a while.

Hi,

Try using the search function. Even though I drive a 1Z model, it sounds like a problem with the turbocharger's wastegate control (-> possibly a stuck wastegate?). There's been a lot of discussion about this in the forum! A more important search term: "VTG".

Hello,

The box was already damaged before the chip tuning. It's actually logical, isn't it, if you don't reach the maximum speed specified in the vehicle registration document?

Rainer.

@ haehnlein

der AHU hat doch keine VTG !?! Or ???

It's just a "renamed" 1Z.

m;

dieselmartin wrote:

It's just a "renamed" 1Z?

....I thought it was VTG. In any case, it must be located in the area of the magnetic valve for turbocharger pressure limiting (hoses, valve itself, etc.).

"Well, Rainer is probably right. If a car can't even reach its registered top speed going downhill, I'd try to fix the problems with the original setup before even thinking about tuning it."

Matthias.

Hi,

I assume that you have a motor with a VTG (Variable Turbine Geometry).
They have a problem that occurs when they are turned up too high.
'chip that increases the boost pressure. Since the VTG system is designed for...'
If the system is designed for 90 horsepower, VTG can provide the necessary regulation.
There shouldn't be any more pressure on that.
And if the boost pressure cannot be reduced,
Then the control unit switches to emergency mode.

Some tuning boxes have the property that...
it revs up, but it shuts off when you give it gas, and if...
As the speed decreases, it resumes its function.

If I were you, I would first try the car without the chip.
Bring order.
Before starting the work, you should check the diesel filter beforehand.
including checking the diesel lines.
Then:

1. Measure boost pressure, especially if it's too high.
2. Then, connect the solenoid valve to the hoses.
Check the VTG (Variable Turbine Geometry) - new magnetic valve approximately 90 Euros.
The VTG (Variable Turbine Geometry) can also be tested with the engine running.
When idling, the membrane dose rises all the way to the top.
Maximum charging pressure achieved.
Then you can disconnect the vacuum hose to the VTG.
If the membrane bag is now pulled down completely along the VTG rod...
If it's shifting smoothly, you can assume that your VTG (variable transmission gear) is working properly.

3. If everything has been going well so far, then you should...
Have the mass airflow sensor checked.

Hello,

'Thank you for the quick responses. I went back to Audi yesterday, and the master technician took me on a free test drive and measured the boost pressure and mass airflow sensor; everything was within the normal range. He suspects either the wastegate pressure sensor or the AGR valve.'
The error memory is also empty.

I'll check that.

Thank you.

Hmm? What now? Doesn't the AHU have a wastegate?

Just out of curiosity: What is the difference between a 1Z and an AHU engine? Does anyone know? I once looked at an AHU engine at a colleague's place in the 3B department, and I couldn't see any difference compared to my 1Z (except that the AHU was installed longitudinally, which made it much easier to access the turbocharger ).

Wasn't there something about the emission standard? Didn't the AHU engine have different injectors and a different engine control unit to meet the Euro 3 standard, or am I mistaken?

Best regards, WarLord.

Quote:

Yesterday, I went back to Audi, and the master technician gave me a free test drive, measuring the boost pressure and mass airflow sensor; everything was within the normal range. He suspects either the pressure sensor of the wastegate

.

Oh my God, what is this nonsense again?

Either the boost pressure was within the specified range during the correctly performed measurement, in which case the boost pressure control is working properly, or the boost pressure is not correct, indicating a faulty boost pressure control system.

With a faulty wastegate pressure sensor , the boost pressure may not be correct !

I somehow suspected that only nonsense would come out of this, considering the email I received regarding the employee service hotline... Please only ask questions if you a) are able to understand the numerous technical articles on the subject and b) can make sense of the answers provided in the forum.

Repeating something that is twisted, misunderstood, or completely misunderstood in the workshop is unacceptable.

Therefore, this thread will now be closed. Please review the relevant technical articles again and, if necessary, perform the appropriate checks yourself.