Will an EVM or HSM Void my CPO Warranty?
I know certain dealers handled things differently and it can even come down to the service rep, but this is only in the situation where things do technically void the warranty.
I also know some brands may be approved and won't void warranties, is there a situation such as that with MB and RENNTech or maybe weistech?
I'm just excited that it is so easy to both be able to control ride height(and not have it be permanent) as well as control how loud the exhaust is so easily and to the fullest extent. So, looking forward to do both these little mods, but want to hold off for a little while if MB will know i used them(as in they leave a trace) and if it'll void my warranty. Also 2nd part of the question, should i stick with RENNtech when buying these 2 items? Or are there other companies that make versions of the same thing for half the price and same quality?
Again I apologize for what may seem like well known questions I am new to MB, I've had several fun german cars, but this is my first MB, and I love it!
Last edited by 964+m157; Jan 15, 2023 at 10:48 PM. Reason: HSM was wrong, it’s DLM
I know certain dealers handled things differently and it can even come down to the service rep, but this is only in the situation where things do technically void the warranty.
I also know some brands may be approved and won't void warranties, is there a situation such as that with MB and RENNTech or maybe weistech?
I'm just excited that it is so easy to both be able to control ride height(and not have it be permanent) as well as control how loud the exhaust is so easily and to the fullest extent. So, looking forward to do both these little mods, but want to hold off for a little while if MB will know i sued them and if it'll void my warranty. Also 2nd part of the question, should i stick with RENNtech when buying these 2 items? Or are there other companies that make versions of the same thing for half the price and same quality?
Again I apologize for what may seem like well known questions I am new to MB, I've had several fun german cars, but this is my first MB, and I love it!
Literally any mod you do to the car from air filters to apparently different size wheels and tires could void your warranty.
if you have a blinker that’s put they’ll probably cover. If your $30K trans takes a poop, you’ll have a fight on your hands.
Pretty sure ASR will not ship these to the USA.
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Not really sure what you mean. ASR will not ship exhaust modules to the US because they have an agreement with Renntech not to do so.
There are ways around it....but no one has been getting these shipped directly from ASR to the US.
In that case though, OP could also order from one of the resellers in Germany or maybe even resellers in Austria. I guess just make sure they are reputable though. Another method which it just randomly came up in my head but not sure if it will work would be to ship to a forwarding service and then have it ship to USA.
there are ways around it, but probably not worth it. You’re going to spend more on shipping, possibly have delays with customs, and at the end of the day save very little, or just order from RennTech, and have the support as well as installation instructions in English.
there are ways around it, but probably not worth it. You’re going to spend more on shipping, possibly have delays with customs, and at the end of the day save very little, or just order from RennTech, and have the support as well as installation instructions in English.
I know certain dealers handled things differently and it can even come down to the service rep, but this is only in the situation where things do technically void the warranty.
I also know some brands may be approved and won't void warranties, is there a situation such as that with MB and RENNTech or maybe weistech?
I'm just excited that it is so easy to both be able to control ride height(and not have it be permanent) as well as control how loud the exhaust is so easily and to the fullest extent. So, looking forward to do both these little mods, but want to hold off for a little while if MB will know i sued them and if it'll void my warranty. Also 2nd part of the question, should i stick with RENNtech when buying these 2 items? Or are there other companies that make versions of the same thing for half the price and same quality?
Again I apologize for what may seem like well known questions I am new to MB, I've had several fun german cars, but this is my first MB, and I love it!
buyer beware with mods.
Last edited by PeterUbers; Jan 9, 2023 at 03:20 PM.




once your car is flagged, every repair from changing a wiper blade to swapping engine mounts must be approved by the supervisor.
All SA’s are under intense pressure to report any mods, their jobs depend on it. Yes of course you can be really cool with your SA but your yearly Christmas bottle of wine will not carry weight when they find out your SA has been approving $$$$$$ of repairs on a modded car. Also, my understanding is that the techs have a duty to look for software updates/tunes. They too must report to the system and upload readings.
bottom line, if your car is flagged your warranty is basically worthless and to complicate matters, every repair is scrutinized and the dealers just really don’t want to deal with it.
The good old days are gone boys. These new computers can read everything. Even if you take tune off before going to dealer, they can read that changes to software was made, and even gather history of afrs/boost/etc. so even with no “detectable” tune, they’ll see that something was off coincidentally between service visits.
One hack I have though about is third party warranty. The dealers get paid in the repair regardless, and with the car sales game in the dumpster any income is better than no income. My read is that SA’s and dealers would be more open to completing repairs on tuned vehicles IF that repair bill is paid by a third party and not the hand that feeds them. I haven’t tested the theory and don’t really understand how it all works, but once my OEM expires I’ll explore a third party before extending OEM.
All the module does (I think) is that it intersects and tells the actuator to fully open the exhaust valves, there is no hardwiring to the SAM or anything but I guess according to other forum members it may be possible to be detected and it is a YMMV with dealerships.
My final advice on this based on what everyone else mentioned is, keeping things stock especially if you have a factory warranty. I never had experience with the suspension module you talked about hence why I said what I said in the initial post.
but I was told by several people including ReNNTech that both these items, the ELM and EVM don’t leave a trace in the computers.
so as long as I return it to stock (both through stock selections and removing the devices) before bringing it in I believe I should be fine. I understand there is a risk, and I’m taking some other measures and precautions as to be extra careful, but I think I’ll be fine using these and removing prior to service/warranty work.
but I was told by several people including ReNNTech that both these items, the ELM and EVM don’t leave a trace in the computers.
so as long as I return it to stock (both through stock selections and removing the devices) before bringing it in I believe I should be fine. I understand there is a risk, and I’m taking some other measures and precautions as to be extra careful, but I think I’ll be fine using these and removing prior to service/warranty work.
that’s amazing advice. Did you ask if they’ll cover the cost of your repair if they’re wrong?





