🔐 PCR2.1 IMMO OFF and VAG IMMO OFF Solutions for MED17 / EDC17 / SIMOS / DSG

1) Overview of IMMO OFF services 🔓

Immobilizer off (IMMO OFF) disables the immobilizer function inside the ECU or TCU so that the engine or gearbox can operate without a coded key or matched module set.

When IMMO OFF is useful

This is especially useful when:

• 🔧 Replacing a defective ECU or TCU – Use a donor unit without complex adaptation procedures
• 🔄 Performing engine or drivetrain swaps – Move ECUs between different vehicles or engine families
• 🏁 Building motorsport or off-road vehicles – Eliminate OEM immobilizer systems for race/track applications
• 🛠️ Workshop efficiency – Reduce diagnostic time and avoid costly dealer programming

How immobilizer systems work

In modern vehicles, the immobilizer chain typically involves:

🔑 KEY → 📊 CLUSTER → 🔌 BCM (Body Control Module) → 🖥️ ECU/TCU

Each component must recognize and authenticate the others. IMMO OFF modifies the ECU/TCU to bypass this authentication requirement.

⚠️ Important: On newer vehicles (MY2009+), a full IMMO OFF can allow the engine to start but may affect body functions (e.g. windows up/down via BCM) and generate immobilizer messages on the cluster. Always verify behavior on the specific vehicle.

2) PCR2.1 IMMO OFF (Flash-based) 🎯

PCR2.1 IMMO OFF is one of the most requested solutions in the VAG world, especially for PCR2.1-based 1.6/2.0 TDI engines where standard ECU cloning is often complex or blocked by security.

What makes PCR2.1 special

• 🔒 High security – PCR2.1 ECUs have strong immobilizer protection and tuning lockouts
• 🚗 Wide usage – Found in millions of VAG 1.6 and 2.0 TDI vehicles across multiple brands
• 🔧 Difficult adaptation – Traditional cloning and EEPROM methods often fail or trigger errors
• 💰 Cost-effective – Enables reuse of donor ECUs instead of expensive dealer replacements

How PCR2.1 IMMO OFF works

The patch is applied directly in the FLASH memory, providing a total IMMO OFF state suitable for ECU replacement and engine swaps.

Common PCR2.1 applications

• VW Golf, Passat, Tiguan 1.6/2.0 TDI
• Audi A3, A4, A6 1.6/2.0 TDI
• Seat Leon, Altea 1.6/2.0 TDI
• Skoda Octavia, Superb 1.6/2.0 TDI

3) MED17 / EDC17 EEPROM IMMO OFF 💾

This service disables the immobilizer and corrects checksum directly in the EEPROM for older-generation ECUs.

Supported ECU families

Technical details

• 📍 Patch location – Applied in EEPROM area only
• ✅ Checksum – Automatically handled by the solution
• 🔧 Output – Ready-to-write file for supported tools
• ⚡ Speed – Fast EEPROM programming (minutes vs hours for FLASH)

💡 Advantage: EEPROM IMMO OFF is faster and simpler than FLASH-based solutions. Ideal for older ECUs where EEPROM access is straightforward.

4) MED17 / EDC17 FLASH IMMO OFF ⚡

This option provides a total IMMO OFF in FLASH only for MED17 / EDC17 ECUs used by VAG group. It does not require EEPROM modification and is designed to avoid DTCs or immobilizer error messages on the cluster.

Key features

• 🎯 Automatic detection – Algorithm automatically detects ECU type and applies correct patch
• ✅ Tested extensively – Validated against thousands of MEDC17 files from multiple models and years
• 📊 No EEPROM needed – Works with FLASH-only read/write
• 🚫 Clean operation – Designed to avoid DTCs and cluster warnings

Supported ECU examples

⚠️ Important: MED17 / EDC17 FLASH checksum correction is not performed by the IMMO OFF logic itself. Your writing tool must handle FLASH checksum when programming the ECU.

Special highlight: Audi RS3 2.5T MED17.1.62

🏎️ Performance application: The MED17.1.62 IMMO OFF is particularly valuable for RS3 engine swaps into other vehicles (Golf R, S3, TT RS, etc.). This ECU controls the legendary 2.5T inline-5 engine and is frequently used in performance builds.

5) SIMOS FLASH IMMO OFF 🚀

This is a full IMMO OFF solution in FLASH for SIMOS ECUs, including checksum correction. The generated file is locked to the specific ECU.

Requirements

• 📖 Full BSL/BOOT read required – No virtual read accepted
• ✅ Complete solution – IMMO OFF applied in FLASH + checksum calculated and corrected
• 🔒 ECU-specific – Output file is ready to write back to the exact ECU

Supported SIMOS variants

Common applications

• SIMOS 18.x – Modern VAG petrol engines (1.4 TSI, 1.5 TSI, 2.0 TSI EA888 Gen3)
• SIMOS 12.x – Mid-generation TSI/TFSI engines
• SIMOS 10.x – Older TSI/TFSI platforms
• SIMOS 8.x – Legacy VAG petrol engines

✅ Complete solution: SIMOS FLASH IMMO OFF is the most comprehensive option – everything handled in one step, including checksums. Just read, send, flash back.

6) VAG DSG TEMIC IMMO OFF 🔄

For VAG DSG TEMIC gearboxes, the IMMO OFF solution provides total immobilizer bypass for the TCU (Transmission Control Unit).

Supported DSG variants

Technical requirements

• 📖 Full EEPROM read required – Complete EEPROM dump needed
• 📖 Full FLASH read required – Complete FLASH dump needed
• ✅ EEPROM checksum – Performed automatically on EEPROM
• ⚠️ FLASH checksum – Must be managed by your writing tool
• 🔧 VIN editing – Allows VIN modification where supported

When DSG IMMO OFF is needed

• 🔧 TCU replacement – Replace defective transmission control unit with donor
• 🔄 Gearbox swaps – Install DSG from different vehicle
• 🏁 Motorsport builds – Eliminate immobilizer for race applications
• 💰 Cost savings – Avoid expensive dealer adaptation procedures

📌 Note: DSG TCU and Engine ECU often share immobilizer data. For complete IMMO OFF in a swap scenario, you may need to address both ECU and TCU.

7) Complete list of supported ECUs and TCUs 📋

The IMMO OFF logic supports a wide range of ECUs and TCUs. The following families are supported:

🔴 Bosch ME(D)C17 / MG1 / MD1 (VAG Group)

🔵 Bosch EDC17 (Diesel ECUs)

🟢 Siemens / Continental

🟡 Delphi ECUs

🟣 Valeo ECUs

⚙️ Other ECUs

📌 This list is representative, not exhaustive. Coverage extends to many additional MEDC17, MG1, MD1, Delphi and SIMOS file variants within the same families.

8) Pricing and quotes 💰

💬 Request a quote

For pricing and specific project evaluation (especially for PCR2.1 IMMO OFF and complex VAG platforms), please submit a request via TuningBot.com → Quote task.

Please provide:

• 🔧 ECU/TCU type – Exact model and version (e.g., PCR2.1, MED17.1.62, SIMOS18.1, DQ250 MQB)
• 📖 Read method – EEPROM only, FLASH only, or both / BOOT/BSL read capabilities
• 🚗 Vehicle details – Make, model, year, engine code
• 🎯 Use case – ECU replacement, engine swap, motorsport build, etc.
• 📋 Special requirements – VIN change, specific checksum handling, etc.

This information allows us to guide you to the correct IMMO OFF option and provide accurate pricing.

9) Frequently asked questions ❓

When should I use an IMMO OFF solution?

IMMO OFF is typically used when replacing a defective ECU or TCU, when performing engine or drivetrain swaps or for motorsport and off-road projects where the original immobilizer system is not required. It is not intended to bypass security on otherwise healthy vehicles for theft purposes.

What is special about PCR2.1 IMMO OFF?

PCR2.1 ECUs are widely used on VAG 1.6 and 2.0 TDI engines and are often difficult to clone or adapt due to security and tuning protection. A dedicated PCR2.1 IMMO OFF flash solution lets you reuse donor ECUs for engine swaps or replacements without needing a full immobilizer adaptation procedure at the dealer.

Do these IMMO OFF solutions cause DTCs or cluster immobilizer messages?

The MED17 and EDC17 FLASH IMMO OFF, PCR2.1 IMMO OFF and SIMOS FLASH IMMO OFF solutions are designed to provide a total immobilizer-off state on supported ECUs without immobilizer DTCs or cluster error messages. However, behavior may vary by vehicle configuration and instrument cluster, so real-vehicle testing is always recommended.

Do I need a full BSL/BOOT read or is virtual read enough?

For PCR2.1, SIMOS FLASH IMMO OFF and many MEDC17 solutions, a full boot or bench read is required. Virtual read is not sufficient, because the patch must be applied to the exact file that belongs to the ECU on the bench, including its specific software version and checksums.

Are checksums handled automatically?

It depends on the solution:

• ✅ Automatic: EEPROM-based IMMO OFF, PCR2.1 IMMO OFF, SIMOS FLASH IMMO OFF
• ⚠️ Tool-dependent: MED17/EDC17 FLASH IMMO OFF, DSG FLASH memory – your writing tool must perform final checksum

Is IMMO OFF legal for road use?

Regulations vary by country. In many regions, altering the immobilizer system may not be allowed on public-road vehicles. These IMMO OFF solutions are offered for ECU replacement, engine swaps and motorsport or off-road applications. It is your responsibility to ensure compliance with all local laws and regulations.

Can IMMO OFF affect other vehicle functions?

On newer vehicles (2009+), while the engine will start after IMMO OFF, some body functions may be affected because the BCM (Body Control Module) still expects proper immobilizer communication. Examples include power windows, central locking, or comfort features. The extent varies by vehicle and model year.

What’s the difference between EEPROM and FLASH IMMO OFF?

EEPROM IMMO OFF: Applied in the small EEPROM chip, faster programming, suitable for older ECUs (ME7, EDC15, EDC16, MED9).

FLASH IMMO OFF: Applied in main program memory, requires full boot/bench read, suitable for newer ECUs (MED17, EDC17, SIMOS, PCR2.1) where EEPROM-only solutions don’t work.

Can I use IMMO OFF for theft recovery or lost key situations?

IMMO OFF can technically allow engine starting without coded keys, but it’s not the recommended solution for legitimate ownership situations. Proper key programming through dealer or locksmith is the correct approach. IMMO OFF is intended for ECU replacement, swaps, and dedicated motorsport/off-road builds.

Conclusion 🔐

TuningBot’s comprehensive IMMO OFF solutions cover the most common scenarios professional tuners and workshops face:

• ✅ PCR2.1 IMMO OFF for difficult-to-adapt TDI ECUs
• ✅ MED17/EDC17 solutions for VAG petrol and diesel platforms
• ✅ SIMOS FLASH IMMO OFF for modern TSI/TFSI engines
• ✅ DSG TEMIC IMMO OFF for transmission swaps
• ✅ Wide ECU coverage across Bosch, Siemens, Delphi, Valeo families

🎯 Professional approach: Whether replacing defective ECUs, building engine swaps, or creating motorsport projects, proper IMMO OFF solutions save time, reduce costs, and eliminate dealer dependency. Always verify local regulations and test thoroughly before delivery.