Siemens SID803A ECU Tuning

Engine control unit used in 13 supported models from 4 makes.

Citroen with the Siemens SID803A

Fiat with the Siemens SID803A

Lancia with the Siemens SID803A

Peugeot with the Siemens SID803A

About Siemens SID803A tuning

The Siemens SID803A engine control unit is supported in 13 models from Citroen, Fiat, Lancia, Peugeot. We read, modify, and flash it with AutoTuner, then verify the result on our Dynojet 424xLC2 in Jenison, MI. A custom calibration optimizes fueling, ignition timing, boost, and torque limits for your exact build.

Browse all supported ECUs and TCUs

Don't See Your Vehicle?

These lists cover off-the-shelf tuning platforms. We also do standalone ECU installs and custom calibrations, so reach out and we'll tell you what's possible for your build. Compatibility data last updated 2026-09-24.