MS45 Doubled MAF Sensor Range
Posted: Mon Apr 13, 2020 11:04 pm
We're proud to announce the first publicly available tune to double the MAF sensor range for the MS45 community! We've spent a little time analyzing the disassembly in IDA Pro and came up with a couple of proposals for this firmware hack. The first idea ended up working exactly as expected! A huge thanks goes to forum member snelan who was the first to beta test this for us on his supercharged MS45.1 project!
Now, onto the important details! When applying this hack, we modify the program portion of the binary which usually isn't touched during the tuning process. In doing this, it's necessary to perform a "full" flash which takes a significant amount of time for MS45.x (even when using fast baud rate). Therefore, please make sure both your laptop and vehicle battery are connected to chargers during the flashing process. Also make sure your headlights are turned off and your engine fan is unplugged (some vehicles turn on the fan even if the engine is not running). If your battery voltage gets too low or if your laptop turns off in the middle of the flashing process, you risk putting your DME into a state where it cannot respond appropriately to ByteTuner. It's almost impossible to "brick" these DMEs regardless of what some people online say. However, it's easy to corrupt it such that ByteTuner cannot communicate with it if the flashing process is disturbed. If this happens, you'll have to ship your DME to someone who can recover it using other tools. We have this capability, but it's not free.
The second import thing to keep in mind about this firmware hack is what we didn't change in the tune. The main things we changed in the tunes below are the actual firmware hack and scaling the original MAF sensor curve by 0.5. There are several other parameters which reference the MAF sensor, either as parameters themselves or as the axes of other maps. We did not touch the scaling of these at all! Forum user snelan did a good bit of driving and logging while he was testing this tune. He didn't notice any strange behaviors during all of his testing. However, keep in mind that some of these parameters are not always active. Some of these parameters could become active only during certain situations (such as during limp mode). We've attached a spreadsheet below showing all of the other parameters that reference anything which has units of kg/h. Some of these parameters reference the MAF sensor and some reference other things such as secondary air flow. We will let you judge what is important and what isn't. Please review this document and make your own judgements of what might be important. Also, use good judgement when applying this tune and when testing/logging. If you discover something that should also be scaled by 0.5, please let us know ASAP and we can make changes to the tunes below.
For now, we've only applied this hack to the most popular stock tunes that we include with ByteTuner. If you need a different ZB/HW/SW variant that is not below, please let us know. You will need to give us the ZB number or the HW + SW numbers.
Now, onto the important details! When applying this hack, we modify the program portion of the binary which usually isn't touched during the tuning process. In doing this, it's necessary to perform a "full" flash which takes a significant amount of time for MS45.x (even when using fast baud rate). Therefore, please make sure both your laptop and vehicle battery are connected to chargers during the flashing process. Also make sure your headlights are turned off and your engine fan is unplugged (some vehicles turn on the fan even if the engine is not running). If your battery voltage gets too low or if your laptop turns off in the middle of the flashing process, you risk putting your DME into a state where it cannot respond appropriately to ByteTuner. It's almost impossible to "brick" these DMEs regardless of what some people online say. However, it's easy to corrupt it such that ByteTuner cannot communicate with it if the flashing process is disturbed. If this happens, you'll have to ship your DME to someone who can recover it using other tools. We have this capability, but it's not free.
The second import thing to keep in mind about this firmware hack is what we didn't change in the tune. The main things we changed in the tunes below are the actual firmware hack and scaling the original MAF sensor curve by 0.5. There are several other parameters which reference the MAF sensor, either as parameters themselves or as the axes of other maps. We did not touch the scaling of these at all! Forum user snelan did a good bit of driving and logging while he was testing this tune. He didn't notice any strange behaviors during all of his testing. However, keep in mind that some of these parameters are not always active. Some of these parameters could become active only during certain situations (such as during limp mode). We've attached a spreadsheet below showing all of the other parameters that reference anything which has units of kg/h. Some of these parameters reference the MAF sensor and some reference other things such as secondary air flow. We will let you judge what is important and what isn't. Please review this document and make your own judgements of what might be important. Also, use good judgement when applying this tune and when testing/logging. If you discover something that should also be scaled by 0.5, please let us know ASAP and we can make changes to the tunes below.
For now, we've only applied this hack to the most popular stock tunes that we include with ByteTuner. If you need a different ZB/HW/SW variant that is not below, please let us know. You will need to give us the ZB number or the HW + SW numbers.