Manufacturers: Ford, Mazda
Brand: Siemens
Model: SIM21
Function: Immo off
Emulator: No
Siemens SIM21 Immo Off: Ford ECU Immobilizer Solution
The Siemens SIM21 is an engine control unit (ECU) found in selected Ford petrol vehicles, including the Ford Fiesta Mk5 1.3 Duratec. Its immobilizer system controls engine-start authorization by checking the communication between the ECU and the vehicle’s security components.
A Siemens SIM21 immo off solution disables the immobilizer authorization requirement within the ECU. This modification may be useful for authorized ECU replacement, electronic repairs, or diagnostic testing when immobilizer synchronization prevents normal engine operation.
Before requesting an immobilizer modification, technicians should identify the exact Siemens SIM21 hardware and software version. Compatibility must be confirmed using the ECU identification rather than the vehicle model or engine specification alone.
Siemens SIM21 Immo Off with CK Decode
CK Decode provides automotive technicians with ECU file processing solutions through its online immo off service. For Siemens SIM21 applications, technicians can check whether an immobilizer-off modification is supported for their specific ECU software.
The immo off procedure is different from an immo virgin operation. Immo off removes the immobilizer authorization requirement, while immo virgin prepares an ECU for initialization or pairing with a vehicle’s immobilizer system.
Ford Vehicle Applications to Check for Siemens SIM21 Compatibility
The following Ford petrol models and engine variants are included in the supplied application list. Their individual Siemens SIM21 compatibility must be verified before ECU file processing.
Ford Fiesta Mk5
- 1.25 16V – 70 CV (51 kW) / 75 CV (55 kW)
- 1.3 8V – 60 CV (44 kW) / 70 CV (51 kW)
- 1.4 16V – 80 CV (59 kW)
Ford Ka (First Generation)
- 1.3 8V – 60 CV / 70 CV
- 1.6 8V – 95 CV (70 kW)
Ford Fusion (First Generation)
- 1.25 16V – 75 CV (55 kW)
- 1.4 16V – 80 CV (59 kW)
Compatibility note: The project ECU database explicitly identifies Siemens SIM21 applications for the 2002 Ford Fiesta Mk5 1.3 Duratec. The other listed variants require individual ECU verification. Vehicle model and engine specifications alone do not guarantee compatibility.
How to Perform Siemens SIM21 Immo Off with CK Decode
To process a Siemens SIM21 immo off file using CK Decode, follow these steps:
- Download CKDecode through this link
- Click on the Functions Tab and select Manufacturer – SIEMENS – SIM21 – Immo off
- Read Flash with your interface and upload the file
- Click Process button
- Write the file processed by CKDecode
