Pre Sale Question MS45.1

[DrexelLake]

Is the tune done with the file still in the ECU on the car? Then using the GUI make the changes, or download the file, make changes, then upload to the ECU?

Does anybody have the location for coding out the SAP and O2?

[Renovelo]

Usually the first step is to read the tune which already exists on the DME. This allows you to make a backup if you ever want to revert your DME back to the way it was before ByteTuner. If the tune you download from your DME is one of the HW variants supported by ByteTuner, then you can tune this file directly and flash it back to your DME. If it's not one of the supported HW variants, then you can use any of the stock tunes or modified tunes which are compatible with your DME as a starting point. Make sure to reference this page to determine which ZB/HW/SW variant you need for your specific vehicle.

Our software does not require you to know the addresses of any parameters. We provide you with all of the map packs ready to go so all you need to worry about is tuning.

[DrexelLake]

Thanks. I've been having a problem with my tune after installing a supercharger. The issue is when the custom tune hits around 300 miles there's hesitation and break up on light acceleration. Seems to run fine other than that. It returns at around the same mileage after resetting adaptations. I went back to the tune that came with the supercharger from VF Engineering and it runs fine. Just has the check engine light because that tune doesn't do away with the O2 and SAP codes being that it has catless headers and a SAP delete. So I got refunded for the custom tune because they couldn't figure it out. Found out the tune shop has some guy in Egypt remoting in to tune for them.

So all I really need to do is code out the O2 and SAP. I have a HEX tuning cable and software to download and upload the file. This appears to me exactly what I need. I'm assuming I can open the file with this software and select or deselect options for SAP and CO2, correct? If not I can use the info from the MS45 Wiki.

My hardware and software don't seem to match up exactly with your list. 7561519 shows as 330i, I have the 330ci auto.

ECU Type : Siemens DME MS45.1
Vehicle Manufacturer Ecu Hardware Number : 7561382
Vehicle Manufacturer Ecu Software Number : 7561519

[Renovelo]

It's impossible for us to guess to what could be causing this behavior with your tune. However, in the hands of a qualified tuner, ByteTuner can be used to tune for nearly any modifications. We've heard several success stories with customers and supercharged MS45 setups, so it's definitely possible.

As for removing CELs, you can see the post to your question from another member: viewtopic.php?t=1786

Since your HW variant matches what ByteTuner supports for MS45.1, we can build a *.dme2 file for you with the proper SW variant if necessary. This will ensure that you're using the exact same stock base tune.

Note: Some tuners have mechanisms to protect their IP. Don't expect ByteTuner to be able to circumvent these protection mechanisms if they're in place with your existing tune. In some cases, you may need to start tuning from scratch (100% bone-stock file).

[DrexelLake]

I talked to you a while back about the VF Engineering tune file being encrypted. It's only encrypted for emailing to you. It is decrypted when uploaded to the ECU using their HEX Flash cable and software. It can then be downloaded again and edited as needed. I plan to edit their file so the supercharger parameters are already there. Just need to code out the SAP and O2 using the MS45 Wiki. Thanks

[Renovelo]

Protection mechanisms can be more than just OBD2 read locks. Tuners who really know how to disassemble DMEs can move the parameters around to different places in memory. This is actually quite easy to do. We've done this before to add bigger tables to some DMEs. If you read the tune and edit a certain parameter, the DME may not even be using that parameter any longer and you'll wonder why your changes have zero effect on the engine.

It's also possible to "encrypt" certain parameters such that only the DME can interpret them. If you read the tune via OBD2, the maps will look like garbage in any editor. Big tuners will go to extremes to prevent their IP from being stolen.

[DrexelLake]

I verified with them before deciding to take this up on my own. But if we have to start from scratch that's fine too. I'm retired, so it will give me something to do.

[Renovelo]

Understood. We just like to be very thorough and transparent such that customer expectations are properly met. We've sometimes had very disappointed customers when they realize they can't modify their existing tuned DME and must start from scratch.