Start/stop off

Start/stop is not a button: it is a stop condition evaluated continuously. The ECU looks at engine temperature, the state of charge measured by the battery sensor, brake pressure, steering angle, air-conditioning demand, and then cuts. And it rearms at every ignition cycle, because the mode homologation depends on is the one at start-up.

We make the deactivation permanent in software, without touching the rest: the dashboard, the button and the diagnostics stay coherent, the system simply behaves as if it had been switched off, every single start. Turbocharged engines gain one hot shutdown less, the uprated starter and the AGM battery one wear cycle less, and the driver one restart lag less in traffic. The button itself stays where it is and keeps its indicator: what changes is that the engine no longer shuts itself down at a standstill.

The deactivation is software: the hardware stays in place. The uprated starter, the AGM battery and its charge sensor keep existing and keep being monitored — they simply work less.

Nor is it a cure for a weak battery. A start/stop system that had already stopped cutting the engine often pointed to a battery at the end of its life or a faulty sensor: neutralising the function removes the symptom, not the cause, and the charging circuit deserves a check first.

Two last points: on mild hybrid platforms the engine cut is part of the drivetrain and cannot be treated as mere comfort; and the vehicle's homologation cycle was measured with the function active — switching it off does not change what is written on the certificate.