https://docs.emtronaustralia.com.au/engine-management/functions/diff-control/index.htmlOverview The ECU can electronically control a Differential by modulating a solenoid at a fixed frequency and varying duty cycle. The Differential Control and corresponding output duty cycle is determined by 3 different operating modes. A flow chart in the next section provides a visual overview of how the system works. 1) Handbrake. When this input is configured and the handbrake is ON the ECU applies 0%DC at its control output to unlock the diff. This overrides all other controls.Hugoen-us