Diagnostic Expert Hamburg: Find the Best!

Since my Audi workshop can only read the error codes, I'm looking for a professional in Hamburg who can do more.
Does anyone there know someone?
Audi A6 2.5 TDI 110 kW AFB.
Regarding my issue, I received a new ESP (Electronic Stability Program) about 3 months ago.
I didn't install them myself because of the warranty.
Now, when I turn on the auxiliary heating, I'm experiencing starting problems.
I initially requested a dynamic ESP check, and you said everything was fine.
No errors.
I then checked myself and found that the MSB4 field 4 indicates a key press ratio of 100.2%.
lag.
This, however, doesn't indicate that the ESP is optimally configured.
I then adjusted it myself, and now all the other values are also within the optimal range.
Which was not the case before.
But there's no improvement.
I proactively replaced the temperature sensor used for calculating the preheating time, because...
If I disconnect it, it pre-glows, and then it turns on immediately.
I believe that if the device is no longer providing accurate readings, it could lead to starting problems.
If I don't turn on the standby function and it's already in preheating mode, it turns on immediately.
I think it's related to the fuel injection quantity setting for diesel engines.
I'm not sure.
It's incredibly frustrating when the engine has starting problems when it's cold, but starts perfectly fine when it's already warm.
I also don't want to mess around with the default settings myself, or does anyone have any tips on that?
Also, the diesel filter and recirculation valve are new. The fuel tank vent is also okay.

Check starter speed!
Best regards, ammerlaender.

In my opinion, there are only two possibilities. Either the starter motor is not getting fuel properly, meaning there's a tiny leak somewhere and air is getting into the fuel line towards the ESP, or your battery is not in the best condition, which is causing a reduced starter motor speed.

Hello, the STH is an original part from the manufacturer and has a separate diesel supply.
The Varta battery is one year old, and I connect it to a trickle charger once a week (to prevent sulfation).
Even if I leave the charger plugged in while the car is in preheating mode and then start the car.
It doesn't start, or it starts poorly.
Okay, I can measure the idle speed.
How high does it have to be?
Do you still have the MWB (Mean Well-to-Brake) value in mind, or am I seeing that in the engine speed? I'll try it out.
Best regards,

Are there any anomalies detected in the temperature sensor?

No, I replaced the temperature sensor without any compromises.
That was only 20 euros.
I measured the idle speed after 30 minutes of auxiliary heating, and it was 149 RPM.
I'm sorry, I don't understand what you mean by "sollwer???". Could you please rephrase your question?

If the auxiliary heater is original, it has a separate fuel pickup, and the injection pump cannot draw in air. By the way, there is much more information on this topic in the search function. Regards, ammerlaender.

Hello, Ammerländer.
That was a great tip to check the initial speed and then refer to the search function.
Let me try entering that, but it's showing zero results.
Then it's best not to write anything at all, or is it too difficult to type a three-digit number?

Thank you.

'150 RPM seems a bit low to me, even though I don't know the exact target values... but if I had to guess, I would say at least 100 RPM higher.'

Starterdrehzahl sollte min.300 U/min betragen (lt. Bosch).
I found this for you using the search function.
Best regards, ammerlaender!

Hello.
I now used VAG-COM to check the engine speed and observed what was displayed before the engine started.
Furthermore, it was very sluggish; the 149 RPM reading didn't appear until a few seconds later.
I'm not entirely sure if this can be considered a correct value.
How do you measure the starting speed?

ammerlaender Sorry for my sharp reply.
I probably messed up the search function.

ammerlaender wrote:

Starterdrehzahl sollte min.300 U/min betragen (lt. Bosch).

I am also familiar with this starter speed for the four-cylinder TDIs.

Without knowing it, I would have expected the V6 to have a lower RPM, as the idle speed is also lower. However, this is just my gut feeling.

I also think 150 is too low. I believe anything below 200 is definitely too little, even for a V6 engine.

Regards,
Guste.

Was du geschrieben hast: "Ist die Messung, die ich mit VAG-Com durchgeführt habe, so in Ordnung?"
I'll also keep an eye on the battery voltage when starting it up. It's new, and the resting voltage is fine, but... well, you know.
Best regards,

Yes, that's correct. After approximately 5-6 seconds of the startup attempt, you should be able to read a stable value using VAG-COM.
Best regards, ammerlaender.

Okay, I'll definitely test the contacts for corrosion.
Then, also, have a second battery connected while starting.
Best regards,

Hello A6 Andreas!
Could you please provide more details about the relay circuit used to bypass the temperature sensor?
"befriend?" Often, what's perceived as problem-solving by Bosch services is actually just a way to build rapport.
Has this been discussed in this forum before? I think it might have been by Ulf.
Best regards, ammerlaender.