Citroen Saxo KM Calibration 1.0 — service tool for NEC-780826-GC dashboards
Compact Windows utility that communicates over a standard COM port to set a calibrated mileage value on Citroen Saxo instrument clusters based on the NEC-780826-GC MCU.



What it does

• Direct write — enter a new KM value and press Write KM.
• Serial connection — simple Open COM port / Close COM port workflow.
• Focused target — designed for Saxo clusters with NEC-780826-GC electronics.
• Lightweight — portable EXE, ideal for quick bench jobs after cluster repair/replacement.

Typical use cases

• Restoring correct mileage after EEPROM/MCU corruption
• Preparing a replacement cluster for the same vehicle
• Workshop service after instrument panel refurbishment

Quick start

1. Connect your interface and select the correct COM port in the drop-down list.
2. Click Open COM port, enter the New KM value.
3. Press Write KM and wait for confirmation.
4. Click Close COM port and verify the value on the bench/vehicle.

Compatibility
Tested on Windows 10 LTSC (2019). Also runs on Windows 7 / 8 / 10 / 11 (x86/x64).

Minimum system requirements

• OS: Windows 7 or newer (32/64-bit)
• CPU: Dual-core 2.0 GHz+
• RAM: 2 GB (4 GB recommended)
• Storage: <50 MB free
• Extras: Serial/USB-COM interface, stable 12 V bench power

Best practices

• Keep a verified backup of the original data when possible.
• Use a battery support/bench supply to avoid voltage dips during writing.
• Tool is intended for Saxo NEC-780826-GC clusters; other dashboards are not guaranteed.

Legal notice
This tool is for legitimate service tasks only (module repair/replacement and restoration of accurate data). Regulations may apply in your region — ensure full compliance and proper documentation.

Disclaimer
Details are based on the provided screenshot and public information for educational/archival purposes. Any files, if referenced, are hosted by third parties; our forum does not host or distribute software and is not responsible for external content.