Wack

Hi Everyone,
I've been wanting to tune my 2018 C43 cab however it's a lease and I am concerned with the factory MB warranty being affected.

I've been seing some nice posts on the BMS JB1 piggyback which seems to be exactly what I'm in the market for (price and results and easy reversibility), however,
I wonder if it truly is undetectable if I remove the piggyback when I return to the dealer for regular maintenance or warranty service.

If the engine ever had a major problem, would MB be able to know that the car had a piggyback on it even though I would have removed it prior
to taking the car to them with the engine trouble ?

Thanks for your comments

DRLC43

aggies15

Both a piggy-back tune and an ECU tune can be detected by MB if they look hard enough. The main difference is that piggy-backs can be removed by you in 5 minutes, as opposed to a tune where you would need to ship it back to the tuner. Like the above guy said, it wouldn't matter if the car is leased or bought if any issues pop up. The warranty is the same for everyone.

With that being said, most reputable tuners will stand by their product if something goes wrong. Don't be afraid to get your feet wet if you're looking to open up your car a bit more.

18bora

I have actually asked BMS the same question after I bought my unit used from another forum member, and here is their response,
" When you flash the ECU a permanent trace is left behind even if flashed to stock. The internal checksum is changed, the ECU stores the peak target load/torque/boost values in a hidden area of memory, flash counters increment, etc. With a well designed piggyback, the ECU is never aware it's making more than the factory power levels so no trace is left behind when removed. Not all piggybacks are well designed, but the BMS Stage1 is
That said, there are certain risks involved in modifying your car, and if you break something running at higher power levels, wither a flash, or a piggyback, you should pay for the resulting damage."

Basically, if you remove it, MB won't know. However, if you break something (axle, driveshaft, trans, diff, etc...), you should man-up and pay for it yourself.

FTFY

DRLC43

M
My understanding is that is. It true. MB can look at engine parameters that are caotured and recorded and from these they can determined if modifications, including piggyback tunes, were in place at one time.
Again, whether they go to these lengths might be another question, but from what I have read a lot of information is capture which can then be analyzed to determine if the car has undergone a tune.

waisoserious

I dont see how the car can be aware if a piggy back was present, when piggy backs intercept data after the ECU sends them. But then again, I am not the engineer. But...

- AMG Performance Center in town, the sales told me they would not know and they are not able to detect it (a piggy back)
- Dinan told me the same thing
- Racechip told me the same thing
- BMS told me the same thing

However, I put the most stock in the sales at the AMG performance center. He told me this as He was showing me his super super tuned 135i (ecu, headers, intake, meth injection, exhaust, BOV). He and I got into a discussion and I told him I was considering a tune. I asked him the above question and thats what he told me.

18bora

With a full tune, they can tell immediately even if it was flashed back to stock, since the ECU has to be physically opened (broken seal), flash counter, actual boost logs, etc... But with a piggyback, the ECU will see/log factory settings since the piggyback is fooling the sensor to only see factory boost settings. Basically, the ECU sees/logs factory settings. Maybe If they dig-in a little deeper into fuel trims and see how the ECU is adding fuel (AFR correction) to compensate for the extra "Unseen" boost... maybe.... but even then, it could be blamed on a faulty O2 sensor!
I could be wrong, but I can see MB techs looking into ECU tunes for busted axles, driveshafts, trans, etc.. But, I don't see them looking deeper into it unless you blow the engine.
If you're trying to pass a quick one by MB techs, you have a slim chance with a full ECU tune and a good chance with a piggyback.

DRLC43

18bora

A full tune, yes, the dealer will see the added boost, but not with a piggyback.

See the below data from BMS logs:

ECU PSI : is what the ECU sees and records with a piggyback
Target : is what's being requested by BMS and unlike a full tune, the ECU does not see that
Boost : is what you're actually getting, and again..... unlike a full tune, the ECU does not see that either.
Chances of a piggyback car being flagged is very slim, if any vs. a full tune.

DRLC43

threefirs

Some people are giving false information if you are leading people to believe they are 100% safe for warranty repairs with a piggy back. It's misleading and just wrong - because the place you bought it said so is a BS reason to share this. I would say - if you want to mod or tune, you have to pay to play, do not expect MB to take the fault for your hobby. There's a reason people end up back at Dinan for warranty repairs, and there is an increased price with the product. If you buy a JB1, proceed at your own risk. The ECU and modules record and store more than PSI - what about the adjusting fuel/air to compensate for the piggyback's increased boost? MB can see that an ECU has been disconnected. This is not black and white.

MASSC450

There's no way in Hell a dealership would be able to prove I'm running my wimpy Dinantronics Sport...which only connects to the inlet pressure senor and only boosts pressure by 4.0 psi max. I would not feel guilty in the least if something were to blow at only this small increase in pressure.

The only way they'd detect my piggy-back would be if I were stupid enough to leave it connected when I took the car to the dealership. At most, the only case they would have is a malfunctioning inlet pressure sensor.

threefirs

You're right, not very likely as that unit barely produces any power - almost pointless to install. But, if they want to go through the lengths, they'll figure it out.

MASSC450

In fantasy land, maybe...in the real world, they wouldn't waste their time.

DRLC43

18bora

FTFY

MASSC450

Obviously, but I still stand behind my comment about piggy-back tunes...as long as you take them off BEFORE bringing your car to the dealership, it would be tough for the dealership to prove a piggy-back tune was installed...especially if the vehicle never saw track use.

One could counter the issue could have been a malfunctioning sensor or sporadic electrical issue...something ALL make of vehicles are prone to.

Wack

Thanks for your input everyone. Very helpful.
It seems rather clear that the likelihood of them knowing is within an acceptable margin.
I will check out the "warranty friendly mods" section, I did not know it existed.

shardul

iTrader: (1)

Those will be cosmetic mods. Any major power adding mods will not me warranty friendly.

Narry

Generally speaking with a flash there is always a trace left behind, and with a properly designed piggyback like the JB1 there is virtually no way to detect it after the fact. That said you should pay for any damages you cause with tuning.