projectLAMBDA Tuner Information

projectLAMBDA Tuner is map editing software for tuning your stock Subaru ECU. It can also reflash the ECU using BlueSSM.

Download is provided free of charge. All map editing functions are available. License purchase is only required to reflash ECUs.

Getting Started

The first step is to download and run the installer. The software requires Windows 7 or newer to run. It has not been tested on older versions.

Read Factory Calibration

The first step after software installation is to read the factory calibration from you ECU.  It is always recommended to read the factory calibration and save a backup of it for future reference. No flash license is required for this operation. Also, if you haven't setup your BlueSSM device yet, now would be the time to do so.

All ECU operations require the vehicle ignition switch to be turned to the 'ON' position. Do not start the engine, the read may fail if the engine is running. Select 'ECU' -> 'Read' from the menu to begin the operation. A progress window will notify you when the read is complete.

After reading, the factory maps will be loaded for editing. Save this stock calibration so you can come back to it if you need to. projectLAMBDA Tuner calibrations will have a '.tune' file extension.

If your ECU has an aftermarket reflash or your ECU is not yet supported by projectLAMBDA Tuner, you may get a message saying that a 'Full Read' is necessary. This operation will take 2 - 4 minutes to complete. On completion, you will be asked to save the calibration file. Please e-mail this file to so that we can add support for your ECU and get you tuning as quickly as possible.

Any ECU tuned using projectLAMBDA Tuner can also be read using this method.


Create a New Calibration

 The next step is to create a new calibration file. Select 'File' -> 'New' from the menu. This will bring up the 'New Calibration' window.

On the left you will see a list of vehicles. On the right you will see a list of ECU calibrations.


Map Editing

In the main Tuner window, a tree list of available maps is displayed on the left. Click on a map to open a map editor tab for it. Holding shift while clicking a map in the tree will force a new editor tab to open instead of reusing the current tab.

To set the value of multiple cells at once, select the cells then begin typing the new value. Simple math operations (add, subtract, multiply, divide) are also available from the toolbar.

Some maps allow editing of the index values. This can be used to extend the range of the map, for example for higher RPM or boost.

Reflash Operation

The 'Test Write', 'Write', and 'Verify' commands under the 'Tuning' menu are used for reflashing. Any time a flash command is run, the ECU will enter flash mode. This causes the ECU's learned memory to be reset (such as fuel trim, spark trim and idle control, live tuning maps). To exit flash mode, power cycle the ignition switch after any pending commands have completed.

The following should always be checked before running a flash command on your ECU:

  • Car battery is in good condition and charged
  • Laptop battery is charged or plugged in to AC power
  • Turn off any accessories that draw current from the car battery (headlights, ventilation fan, etc.)
  • Green 2-pin test connectors are plugged in (located under the driver side dashboard)
  • Ignition switch is in the 'ON' position, engine is not running
Flash Test Write

If this is the first time flashing your ECU, perform a 'Test Write' first. This will simulate the write operation and is strongly recommended to check that the data link is working correctly. If you haven't reflashed your ECU in a while it is also a good idea to 'Test Write' to check that everything is still working.

Flash Write

After a successful 'Test Write', you can proceed with a full flash 'Write'. If your ECU does not contain a projectLAMBDA license, you will be asked to confirm that you want to add a license. Licenses are not refundable or transferable so use them wisely!

When the 'Write' is complete, turn off the ignition switch and disconnect the green test connector to exit flash mode. You can now proceed to start the engine as normal. Cranking time may be slightly longer the first time after a reflash.

Flash Verify

The 'Verify' command is used to compare the currently loaded calibration to the calibration stored in the ECU's flash memory. This will tell if the current calibration matches or needs updating through a flash 'Write'.

Flash Troubleshooting

If the flash 'Write' operation fails during or after reaching the 'Erase' step, then specific instructions must be followed to prevent 'bricking' the ECU or rendering it inoperable.

  • DO NOT disconnect the battery or allow the ECU to lose power
  • If the write operation failed due to low battery voltage, connect a battery charger or connect an additional battery using jumper cables
  • Retry the flash write operation
  • If the flash write works, run the flash verify command to make sure the ECU flash memory matches current tune

If you still cannot resolve the problem, please contact for assistance.

Live Edit

Live tuning is supported for some ECU types. When you load the calibration of an ECU that supports live tuning, you will see a lightning icon on some of the tree list of maps. These maps can be modified while the engine is running without having to use any flash commands. This convenient feature greatly speeds up the tuning process and reduces wear on the ECU's flash memory. Please note that maps without the live tuning icon will still need to be reflashed using the flash 'Write' method to be updated.

To enable live tuning on an ECU it must first be reflashed with projectLAMBDA Tuner to add the live tuning feature. Then the live maps can be read or written using the 'Tuning' -> 'Live Read' and 'Live Write' commands. The ECU will be running on the newly load maps as soon as the operation completes.

It is recommended to have the vehicle come to a stop before running a 'Live Write' in case you have made a mistake that will cause the engine to stall out.

Live-tuned maps will revert back to the maps stored in flash memory if the ECU is reset either by diagnostic tool or by disconnecting the battery.