Guide
E85, checksum and restoration files explained
This guide covers three services that do not fit a performance category: the E85 flex-fuel conversion file, the checksum-only file, and the back-to-stock restoration file.
E85 flex-fuel conversion
Pricing: Master file price €110 ex VAT · slave (Tier E) €67.
E85 is a blend of ethanol and petrol. It has a higher octane rating but needs roughly 30 per cent more fuel by volume to produce the same energy.
The E85 file adjusts fuelling and timing for the blend. It can only work on a car whose fuel system can supply the extra volume. Injectors, pump and fuel lines must be suitable for ethanol. We cannot fit or check these parts remotely.
Check that the car's materials are ethanol-compatible, and that you can source E85 where you drive. Using the wrong blend is a common cause of lean running and fuel-system faults.
Results vary by engine, fuel, condition and supporting hardware, and no gain or outcome is guaranteed.
Common codes
P0087Fuel rail or system pressure too low. Rail pressure fell below the value the ECU asked for.P0088Fuel rail or system pressure too high. Rail pressure went above the commanded limit.
Checksum only
Pricing: Master file price €26 ex VAT · slave (Tier E) €15.
A checksum file corrects the checksum of a modified binary so the ECU accepts it. It does not change the calibration, so it adds no performance.
Checksum-only is the right service when you have modified a file yourself, or when a tool has changed the binary and the ECU rejects it.
Common codes
P0601Internal control module memory checksum error. The ECU found a checksum error in its own calibration memory. This is common after a file is flashed without a valid checksum.P0606Control module processor fault. The ECU reports an internal processor fault.
Back to stock and original rebuild
Pricing: Master file price €40 ex VAT · slave (Tier E) €24.
This service rebuilds the original factory calibration from your read so the car can be returned to its standard software. It is used before a sale, before a warranty visit or after a trial file.
Keep the original read safe. A rebuild is only as accurate as the source data, so send the clean read you took before any change.
Common fault codes
Codes vary by make, model and ECU. Read the stored codes on your own car before and after flashing.
P0087Fuel rail or system pressure too low. Rail pressure fell below the value the ECU asked for.P0088Fuel rail or system pressure too high. Rail pressure went above the commanded limit.P0601Internal control module memory checksum error. The ECU found a checksum error in its own calibration memory. This is common after a file is flashed without a valid checksum.P0606Control module processor fault. The ECU reports an internal processor fault.
Questions about e85, checksum and restoration files explained
Do I need to change injectors for E85?
Often yes on petrol cars, because E85 needs more fuel volume. Check the fuel system before ordering. The file cannot supply missing fuel.
When do I need a checksum file?
When the ECU rejects a binary you have modified, because the checksum does not match. A checksum file corrects it.
See emissions-related files All questions
Emissions-related files are supplied for off-road, competition, agricultural and export use only, and must not be used on public roads.