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How to Flash Your E90 BMW with TRM Flasher | TRM Tuning

Estimated Read Time: 5 minutes

The TRM Flasher supports flashing for E90-series BMWs equipped with N52, N54, and N55 engines, using ECUs such as MSV70, MSV80, MSD80, and MSD81. This includes the 325i, 330i, 335i, and 335is. Follow the steps below to safely read, back up, and write your TRM tune.

Important: Always use a stable power supply or battery charger during flashing. Voltage must remain above 12.0V. Do not open doors or cycle ignition during the write process.

🧰 What You’ll Need

  • TRM Flasher (download from trmtuning.com/downloads)
  • TRM Tuning calibration file (.enc2 or .bin)
  • K+DCAN cable
  • Windows laptop (Windows 10 or 11)
  • Battery charger or jump pack (recommended)

⚙️ Step 1: Install the TRM Flasher

  1. Download the latest version of TRM Flasher from trmtuning.com/downloads.
  2. Run the installer, allow Windows to trust the application if prompted, and complete the setup.
  3. Connect your cable and confirm detection under Device Manager (“USB Serial Port (COMx)”).

📤 Step 2: Back Up Your ECU

  1. Turn ignition to ON position (accessory mode, engine off).
  2. Open TRM Flasher and click “Connect”.
  3. Select your ECU type — e.g. MSD80, MSD81, MSV70, or MSV80.
  4. Click “Read ECU” to create a backup file. Save it as Stock_Backup.bin.
  5. Wait until the software confirms completion. This may take up to 10 minutes.

Pro Tip: Keep your stock file safe. You’ll need it if you ever return to factory software or switch maps later.

🔥 Step 3: Flash Your TRM Tune

  1. Load your TRM calibration file provided by email after your remote tuning purchase.
  2. Click “Write ECU”.
  3. Do not disconnect the cable or turn off ignition during this process.
  4. When complete, the flasher will confirm “Flash Successful”.

✅ Step 4: Post-Flash Check

  • Cycle ignition OFF for 15 seconds, then back to ON.
  • Start the engine and allow it to idle for 1–2 minutes.
  • Verify smooth idle and no warning lights.
  • If prompted, clear DTCs from the ECU using the TRM Flasher or any compatible scan tool.

🧪 Step 5: Optional Logging

Later E90 ECUs can record data directly using the TRM Flasher’s built-in logging mode or external tools such as MHD logger or INPA live data. For remote tune refinement, log these channels:

  • RPM
  • Load / Request Torque
  • Boost or MAP pressure
  • Throttle (%)
  • Lambdas / AFRs
  • Ignition timing
  • Knock correction

📨 Step 6: Send Data to TRM

Email your logs and ECU info to your TRM tuner for analysis:

Email: tuning@trmtuning.com

💡 Tips for Safe Flashing

  • Never flash with a low or unstable battery.
  • Disable all screen savers, sleep timers, and Windows updates during the process.
  • Switch off headlights, HVAC, and accessories to reduce current draw.
  • Always use the latest TRM Flasher build for compatibility and stability.

With TRM’s official flasher, you can reprogram your BMW’s ECU confidently — gaining the performance, smoothness, and reliability our tunes are known for worldwide.

Download TRM Flasher

Tags: TRM Tuning, TRM Flasher, BMW E90, N54, N55, N52, MSD80, MSD81, ECU Flash, BMW Tune, Remote ECU Programming