BMW MHD Flash Tunes for BMW N54, N55, S55, B58, & N13 Engines

MHD offers flash tunes for the turbo BMW N54, N55, S55, B58, and N13 engines. Their app is easy to use and makes tuning your BMW a breeze. However, the app is only available on android devices. Unfortunately, Apple prohibits the use of 3rd party USB cables, so iOS is out of luck (not completely). Worry not – we’ll touch on this throughout the post. Let’s jump in and discuss the MHD tuning app, features, and how to flash tune your turbo BMW.

MHD Engine Specific Guides

This specific post will cover the basics/general info about MHD tuning. Engine specific guides may be found at the below links (guides are in the works).

N54 MHD Tuning Guide

N55 MHD Tuning Guide

B58 MHD Tuning Guide

S55 MHD Tuning Guide

N13 MHD Tuning Guide

MHD Tuning Background

Early in the N54 days, the tuning community was largely focused on piggyback tuning options. Flash tunes were less common and there were even fewer off the shelf solutions. Enter MHD. The MHD flash tuning maps are easy to install and uninstall. MHD’s app also allows you to data-log and ensure your BMW is running at its prime. Additionally, you can work with tuners to create custom flash maps. MHD offers the following custom flash options, too:

• Exhaust burble (we do NOT recommend this)
• Cold start noise reduction
• Kick-down deactivation
• MT shift bog fix
• Waste-gate rattle fix
• Limit power per gear

These are just a few of the many options that may be used with MHD flash tunes. We also touch on these options a bit more in the engine specific guides linked above. For the remainder of this post we will cover how to flash your BMW ECU and what is required.

How to Install MHD Flash Tunes

Regardless of whether you are installing an MHD flash tune on your N54, N55, etc the process remains the same. We will start with the required items to flash and move on to

Wireless Adapter or K+DCAN Cable

As stated, due to 3rd party USB cables, iOS is not supported with a standard K-DCAN cable. However, there is a solution (also works for Android users, if preferred):

MHD Wireless Adapter – E Series (N54, early N55)

MHD Wireless Adapter – F & G Series (Late N55, B58, S55, N13)

The orange, E chassis wireless adapter is also compatible with the F & G chassis’. However, the black model offers quicker flashing for F & G so is likely the best option for those BMW’s. Both of these cables allow flashing with iOS and Android. For android users, you may opt for a traditional K+DCAN cable if preferred:

K+DCAN Cable

Some of these cheaper K+DCAN cables may be hit or miss. We’ve used the above one for years and dozens of flashes without issue. Keep in mind, the K+DCAN cable features a USB so you will also need a USB converter unless your android device supports USB cables directly.

MHD Tuning Flash App

As you likely guessed, you will need to download the MHD app on your device. This is an easy step as you simply need to pick the correct app for your specific engine. MHD offers 3 separate apps depending on your BMW:

• MHD Flasher N54
• MHD N55 E-Series
• MHD F+G Series

All N54’s should use the top app. E-Series only N55’s should use the second app. The remaining F-Series N55’s and all B58, S55, and N13 engines will use the third option.

Purchasing MHD Flash License

Once the app is downloaded, you will need to establish connection to your BMW with your device and wireless adapter/K+DCAN cable. From there, access the “MHD License Store” to purchase the MHD flash license. The cost of the licenses are as follows:

• N54 – $99
• N55 E Series – $199
• N55 F Series – $249
• S55 – $249
• B58 – $249
• N13 – $249

Next you will need to pick the map pack best suited to your specific BMW. E Series map packs are $49 each while map packs for F+G Series are $99 each. The map packs must be purchased individually, however you do not need to purchase all of the available map packs. Generally, we advise starting with the following maps:

• Tune or Tune + Intake – Stage 1 maps
• Tune + DP(s) + FMIC – Stage 2 maps
• FBO – Stage 2+ maps
• E85 – pick appropriate map for your mods

Flash Your ECU with MHD

Now that you have selected the appropriate map for your engine it is time to flash. A battery charged is REQUIRED for flashing your ECU. The initial flash may take anywhere from 15-40 minutes and you do not want your ECU voltage dropping. Please read the following flash steps:

1. Put device in airplane mode
2. Ensure connection to DME is established
3. Ignition should be ON, but engine OFF
4. Battery charger connected
5. Ensure all cabin accessories (lights) and climate controls (A/C or heat) are all turned off
6. DOUBLE CHECK ALL OF THE ABOVE
7. BACK-UP YOUR ECU/DME in app
8. Click into the map you are flashing
9. Choose transmission
10. Select full write
11. Once flash is complete app will give final instructions

It is a pretty straight-forward process, but can be scary when things don’t go well. As such, we recommend double checking the first 5 steps. It is always exciting to install your first tune, and people may rush through the process and miss a step. Again, we cannot stress the importance of a battery charger and double checking everything prior to flashing.

MHD also offers more in-depth instructions FOUND HERE.

After Flashing Your BMW

Congrats on tuning your BMW! Now, it is always a good idea to data-log and ensure your engine is running well following a tune. MHD offers the monitor module (data-logging module) which we highly recommend purchasing. We wrote a post on data-logging for the BMW N54 engine. While MHD uses slightly different parameters and terminology the aforementioned post may assist in reading logs. Additionally, you may post your logs on the various forums for review.

Final Thoughts on MHD Flash Tunes

MHD continues to be a great option for OTS (off the shelf) flash tunes for the N54, N55, S55, B58, and N13. The ease of installation, excellent features, and proven results make MHD a perfect option for many. Click into our engine specific guides up top for additional information on the various maps/stages and expected power gains. We should note – we personally run JB4 + MHD back-end flashes on all of our BMW’s and highly recommend this setup. However, the JB4 adds an additional $500-600 cost and may not be the best option for everyone.