# Writing a tune to the ECU failed
If the write process failed after reaching the erase step, then the ECU is in a partially programmed state.
- DO NOT TURN OFF THE IGNITION SWITCH
- DO NOT DISCONNECT THE BATTERY
These actions could cause the ECU to stop responding and it will need replacement.
- Determine why the write failed. Sometimes the error message will tell you why.
- Fix the problem that caused the write to fail.
- Run the
Tuning → Writecommand again to complete the write.
- Battery voltage too low
This is most common cause for a write to fail. If this happens you should:
- Turn off any unnecessary electrical loads such as the blower fan and headlights.
- Connect a battery charger or jumper to another battery to bring the voltage back within requirements.
- Flash voltage out of range
TOO LOW - You may have forgotten to plug in a flash connector. Some tuners have been known to cut or remove the flash voltage pin from the ECU.
TOO HIGH - You probably have a battery charger connected. Set it to its lowest current charging mode. Turn on the headlights if it's still too high.
- Random glitch during the erase step
A rare occurence, but it has happened. Try the write again and it will usually work the second time.
- Software bug
Sorry about that! Please let us know if this happens so that we can fix the problem. If you were using the Beta version, switch back to the regular version for now and retry the write.
# Engine won't start after writing to the ECU
Do you hear the fuel pump prime when the ignition is switched on?
- YES - Some settings are incorrect in the tune. You'll need to investigate further.
- NO - The ECU is either still in flash mode or the flash memory has been corrupted by an incomplete write.
Tuning → Readto see if you can connect to the ECU. If you can connect, then the ECU is still in flash mode. You may need to unplug a flash connector before cycling the ignition switch to exit flash mode.
- If you can't connect, the ECU memory may have been corrupted. Try the
Tuning → Recovercommand to see if it helps. If it doesn't, contact support for assistance.
# ECU was powered down in a partially programmed state
OOPS! You really shouldn't have done that. Contact support for assistance.
There is a chance the ECU is recoverable, but the right steps need to be taken in the right order to get it working again. Randomly trying different things may turn your ECU into scrap.
# Failed to connect to [DEVICE NAME]
- The tuning device is not powered on.
- The wrong tuning device is selected in
Tuning → Device Info.
- Power was interrupted to the tuning device while Bluetooth was connected. Windows forces a 20 second delay before it can reconnect.
# Error messages while opening a tune
[SOME ERROR] while loading map: [MAP NAME]. Using factory values instead.
- The tune was created in another version of the software, either older or newer.
- The tune file was edited outside of projectLAMBDA.
- The tune file is corrupted.
As a workaround, the original stock settings will be used instead for that particular map. If you're not okay with that result, you will need to investigate further.