[mike@x-ph.com]

Originally Posted by BigSky702

Isn’t piggyback still a risk? If the computer logs you running outside of stock parameters doesn’t that get flagged??

That's not how it works. Your warranty could not be denied by law unless your mod caused damage that you are asking the dealership to repair for free.

In theory, any modification can be a risk as it can lead to some damage that the dealership can use to deny the warranty, but that's not the case in practice. If you damaged your engine and have a tune and upgraded turbo, don't go to the dealership for a free repair.

If something unrelated stops working, your dealership will honor your warranty no matter what mods you have on your car.

All my cars are fully built, and they are all leases. I get my warranty work done at the dealership without any issues.

Originally Posted by xnick101

Correct. Any time it sees boost over stock parameter threshold it will flag the car.

Piggyback works by tricking the ECU into thinking the car is running stock. Your boost value will all look normal.

[carguy19]

Taking a piggyback tuner or a flash out of your car before going in for service will not prevent the dealer from knowing that the car is tuned. The DME records data, especially when a check engine light comes on, and the dealer/BMW can tell if the parameters of the car's boost, fueling, and timing were altered. Even with the piggyback fooling the car to think its at a stock boost level, the data will show the data being altered from normal. I worked in a BMW store and they know immediately when they plug the car in if it was tuned.

There is a more technical explanation on the mission tuning thread about how the DME records the parameters that BMW can see if the car is tuned. Alex goes into detail about the fact that it can not be hidden anymore.

[carguy19]

Void Warranty Vs "Detectability"
There are quite a few manufactures of aftermarket tuning products claiming that their product is not detectable to a dealer. Yes, that can be very much so as dealer won't be able to tell you what product you had installed (unless of course you left the product in when you took the car to dealer) at the time of failure, but what the dealer WILL in all certainty be able to tell is the fact that your vehicle was performing above preset parameters at time of failure.

As of later 2019, BMW no longer checks your Engine or Transmission modules for checksums/CVNs and other fingerprints of modified files. What they do now is check your acceleration, boost, airmass, and 20+ other parameters. They read those values from few modules around the car, one of them is being ABS.
One of the most important parameters ABS records now is air mass flow and acceleration values. Each time the vehicle is plugged into the dealer tool (ISTA), all of these values are read out and compared against a database values for specific chassis. If these values pass the preset parameters (of course account for % of error), ISTA throws an internal error code "Suspected Engine Tuning" and flags your vehicle on internal database. Of course BMW will not use this as a reason to void your navigation, headlights or most body parts warranty claims, but rest assured that if your turbo fails, you will be presented with a fat bill and warranty be denied based on that flag along.

But what about piggyback boxes that claim undetectable????
Ask yourself this simple question: "By installing this box, did my vehicle become noticeably faster?"
If you answered "YES", then congratulations, your box works as advertised but you just passed acceleration threshold and now you are flagged.
If you answered "NO", then congratulations, your warranty is probably still intact, but you paid $$$ for a useless gizmo box.

Either way you turn it, remember that BMW is smart and has teams of engineers working on detecting any tuning or modifications. And no, a piggyback can not trick or block acceleration reading since ABS picks up that data directly from speed sensors in each wheel as well as uses GPS to eliminate false positives readings, such as dyno runs. If anything, unlike proper flash tuning, piggy back leaves minor evidence of being plugged into the wastegate/boost sensors. Those small traces/marks on physical sensor (and fact that now BMW is starting to mark these sensors with dab of paint) is usually enough for a dealer to know that the car was modified, way before they pull acceleration data.

Moral of the warranty story: Got to pay to play. The moment you made your vehicle accelerate faster, by any means, then it is supposed to, you get flagged. So in the end of the day, forget about warranty question and assume your warranty VOID. For a vehicle that is used like it is supposed to and does not get transported from dyno to dyno, your real question should not be who makes the most power, but instead "who did Toyota TRD choose to tune the first pre-production Supra and most importantly, Why."

Here is the explanation about the DME and how BMW can see if your car is tuned or not. There are no work arounds anymore.

[TruthOne]

lol I think people were just in denial about piggy backs and detectability. Obviously if you're getting 50-70 more HP and TQ the dealer will see that spike.

[Big_red015]

To add I'm running e50 with the kagan salsa catless dp and 225/255 Goodyear exhilarate tires and also xhp stage 3 on my awd m340 and I can say it's very quick only issue is can never hook seems I need to mess with the LC settings with xhp or slight brake boost with dsc completely off. I'm not the best in softwares and kagan helped me a lot and gave me step by step instructions how to load up the tune/software but well worth the investment
Lastly can definitely upgrade to the Visconti flex fuel but that's 2k with the canbus controller and the rest of the kit can well worth put your car on higher performance but at my level I can say I have traction issues which sometimes isn't a bad thing either

[FellowM3]

Has anyone here who was tuned actually been denied.

I fully understand that the dealer sees this and it is flagged. I want to know if anything went in for somethin unrelated to the tune, and if the dealer honored the warranty (like they should)

[mike@x-ph.com]

Originally Posted by FellowM3

Has anyone here who was tuned actually been denied.

I fully understand that the dealer sees this and it is flagged. I want to know if anything went in for somethin unrelated to the tune, and if the dealer honored the warranty (like they should)

Per the data, we have from years on this forum, very close 0% chance of getting denied

[Antares713]

I used JB4 on my E90 N54 335i and Bootmod3 on my N55 F30.
For my G20 M340i I'm thinking either Bootmod3 again or DME