BMW started using the newer CAN communication protocol on the E60 chassis for the MS45.1 DME. On the E46, E83, and E85/E86 chassis, they used the older K-line communication protocol. Since we developed MS45.1 support for ByteTuner around the E46 chassis, we only focused on the older protocol. We've determined that the MS45.1 DME will respond to either the older K-line protocol or the newer CAN protocol. Therefore, you just have to configure everything to use the older protocol which is just a single wire!
All you have to do is run a single wire from the back of your OBD2 port (pin 7) to your DME (plug x60004, pin 32). If you have any wires in your OBD2 port populating pins 6 and 14, you might have to temporarily disconnect those.
Once you make these modifications, you should be able to successfully license your vehicle in ByteTuner. If you don't, or your modifications are incorrect, you will get errors during the licensing process.
After you successfully license the vehicle, you can then read the tune from your DME. It's always a good idea to make a backup copy of your DME before you flash anything. ByteTuner allows you to flash this backup copy back to your DME if you ever want to revert back to the stock condition. Next, you can either use your backup copy (if its the same HW variant supported by ByteTuner) or pick one of the included stock tunes in the library. Make the modifications to the tune and then flash it to your DME. As always, make sure your batteries (laptop too!) are on suitable chargers as the first flash could take a while.
After flashing the DME, your engine should crank and idle without any issues. If you encounter any issues with starting, here are some things to try:
- Read/clear DTCs
- Reset throttle adaptations using ByteTuner
- Disconnect main battery for a few minutes and reconnect
- Try manually resetting throttle adaptations
- Make sure ignition is turned off
- Press the throttle pedal down all the way to the floor (again while ignition is still off)
- Turn ignition to 3rd position (position before cranking; don't crank the engine!) for 30 seconds while holding throttle down the entire time
- Turn ignition off and remove key while still holding throttle down
- After the key is removed from the ignition, release the throttle and wait 30 seconds
- Try starting the car again