Why Originals Matter
Every JB Remap calibration is built on top of the factory map data. When we receive a genuine original file, we can identify the exact ECU software version, verify the checksum, and calculate precise offset adjustments. This guarantees that the final calibration is mathematically correct for your specific ECU variant.
Risks of Submitting a Modified File
A file that has already been tuned by another provider contains unknown changes to map data, limiters, and checksums. Writing a new calibration on top of those changes introduces compounding errors — the result may run rich, lean, or hit safety limiters unexpectedly. In the worst case, it can cause engine damage.
How to Verify Your File
If you are unsure whether your file is original, our engineers can check it during the review stage. Common indicators of a modified file include mismatched checksums, non-standard map values, and calibration metadata that does not align with the ECU software version. We will let you know if a fresh original read is needed.
Related Resources
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Read via OBD, Bench or Boot
Vehicle Details
Model, year and specification
Fuel Information
Fuel type and octane rating
ECU Identification
Hardware and software version