SERVICE · IMMO OFF
IMMO OFF software
Bypass the engine immobiliser so the ECU starts without the original transponder key handshake. For engine swaps, donor ECUs, dead transponders, and lost-key recovery.
Typical symptoms / why workshops apply IMMO OFF
- Engine cranks but won't start after ECU swap
- Lost / damaged transponder key
- Donor ECU from a different vehicle
- Engine swap into a different chassis
What Softechpro V5 actually patches when you select IMMO OFF
- Locates the immobiliser pairing block in the calibration.
- Disables the handshake check at engine start.
- Optionally clears stored EEPROM keys.
- Auto-checksum.
ECU families supported for IMMO OFF
Most Bosch EDC15/16/17 + ME7 + MED17 variantsDelphi DCMSiemens SID
5-step workflow
- Read out your ECU bin file via OBD or bench (KESS3, AutoTuner, MPPS, Trasdata, Flex, FRF flasher).
- Open Softechpro V5 and drop the .bin / .ori / .hex / .s19 / .frf onto the workspace. Softechpro auto-identifies the ECU family from the header signature.
- Select IMMO OFF from the service tab.
- Hit Save patched .bin. The ECU-specific checksum is recomputed automatically.
- Flash the patched file back via your existing flasher. Reset adaptations via the OEM scan tool if required.
Legal notice
IMMO OFF is for legitimate use cases (engine swaps, lost key recovery on owned vehicles). Misuse for vehicle theft is criminal in every jurisdiction.
Frequently asked questions
Will the dash still say "key not detected"?
On most platforms the BCM / cluster still expects a valid key for cabin functions. IMMO OFF only affects the engine ECU's response — the rest of the immobiliser network may need separate handling.