4.0 TDI: Is a Chip Tuned?

Hello,
I recently started driving an A8 4.0 TDI, and it's producing a lot of smoke.
I'm afraid the previous owner might have had the engine performance increased.

How can I tell if a vehicle is original or modified?

Thank you for your help!

Best regards,

Hello,

Please use VCDS to log the parameter blocks 1, 8, and 11 (full load, 1500-4200 rpm) and upload the unaltered CSV file here in the forum.

Best regards, Rainer.

Hello,

While the log file isn't exactly pretty, as far as I can see, the following can be said:
- Turbocharger pressure is original.
- Maximum torque: approximately as expected.
- Performance, based on diagnostic data, approximately 330 horsepower.

In my opinion, it's not original. The increased power likely comes from the standard turbocharger boost combined with a higher fuel injection volume.

Best regards, Rainer.

What should it have had in its original condition? Is there a record of any performance enhancements?

Given the significant deterioration of the vehicle's condition as described, it is reasonable to assume that it would not pass the current emissions test, and that previous inspections may have been falsified.

Quote:

What should it have had in its original condition?

275 horsepower.

Best regards, Rainer.

Thank you!

So, all that's missing now is the air conditioning for the multi-fuel system. Or the retrofitting to the standard trim. }

Stupid question:
Is it possible to query a checksum from these ECUs (I assume EDC16 or something similar?) that can be accessed through any diagnostic tool? I mean, the checksum would be different if a different map was loaded, right?

@Topic starter:
Just go to an Audi dealership and have them update the engine control unit (ECU) to the latest production software; that should remove the modified tuning map. It should be possible to do that without any problems with these ECUs.

Deus Violentia wrote:

stupid question: Can a checksum be queried for these ECUs (I assume EDC16 or?) that is accessible in any diagnostic tool? I mean, it would be different if a different map was loaded....

. . . if you know the checksum of the OEM software

Quote:

@Topic starter: Just go to Audi and have a control unit update performed with the current production data set, which will remove the modified map. That should be possible without any problems with these control units.

AFAIK, authorized workshops don't do updates "just like that," but only with extensive documentation and so on -> which will probably be difficult.

I'm used to it being different; you drop it off, they work on it, and after 20 minutes, you pick it up again for around 25 euros. There was never anything about "extensive documentation" before.

Hello everyone!

Deus Violentia wrote:

I'm used to it being different; you bring it, VAS is there, and after 20 minutes, you take it back for about 25€. There was never anything about "extensive documentation"

.
I'm familiar with this from my T5:
Okay, about a 30-minute discussion about whether or not to proceed with an update, with lots of questions like "why?", "what if?", "who said that?", "how do I know that?", ... "it doesn't exist!" ... "it does exist..." (= we have absolutely no desire to do this!), new appointment scheduled.
Okay, I waited for about 1 hour despite having an appointment, then they connected the VAS, did 10 minutes of "guided troubleshooting," and then waited for about 1 hour for the update (the part number for the MotorStG changed during this process) to finish. The VAS was disconnected, and the soot complaints disappeared IMMEDIATELY - and so did the performance issues .
AND *drumroll*:
3 days later, I received an invoice for almost 140 EUR, including VAT - not bad for 10 minutes of "work," right? ...I wouldn't be so upset if I hadn't been there in person...

By the way, the update was only possible because new software was available for the motor control unit, and it can only be done via an online connection to the VW server, which likely corresponds to the documentation Ulf mentioned.
I don't think the server will allow another update if I try again with the same FIN value, especially if I come back with different data from a different Volkswagen location.

Best regards from Munich!

I've also been through that with the software update. Fortunately, I know someone at the VAG dealership. It's not possible to install another (identical) software update! The control unit already has the latest software.

Rainer K. wrote:

Hello, While the log file isn't exactly pretty, as far as I can see, the following can be said: - Turbocharger pressure is original. - Maximum torque: approximately as expected. - Performance, based on diagnostic data, approximately 330 horsepower. In my opinion, it's not original. The increased power likely comes from the standard turbocharger boost combined with a higher fuel injection volume. Best regards, Rainer

Hi,

If you look at what Rainer wrote, you could almost think that either there's really bad software involved, or maybe there's some kind of hidden "cheating" device connected somewhere!

I'm not really knowledgeable about the technology used in the engine, so I wouldn't know where to look for that information, but it might be worth investigating.

Best regards,

Where exactly is the car located? Perhaps someone could look inside and retrofit something?

Hello.

There are these "cheat boxes" that are plugged directly between the engine control unit (ECU) connector. I had an A4 3.0 TDI with the same symptoms, and it was one of those no-name "cheat" devices plugged in. The connector on the box has the same interface on the back as the ECU, and then the wiring harness connector was plugged into that. We removed it, and the excessive soot was gone. He came because Audi couldn't find any errors, but he was having trouble passing the emissions test .

I'm not sure where the STG is located on the A8, but perhaps someone should take a look there.



Best regards,
Mfg Mpire

Passenger side in the reservoir, both stacked on top of each other .

Hello, even if there were a rigged box inside (yes, there really are people like that), it wouldn't be much better without it.