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Instructions for Activating the Inertia Switch

Model: Ford Focus MK 3 - Years 2011-2018
Part: Onboard computer

After a collision, the engine generally cannot be started because a special device, called the inertia switch, disables the fuel pump. This is a safety precaution as the collision could generate sparks or expose the vehicle to the risk of fire; therefore, the fuel pump is deactivated. To start the engine, it is necessary to reactivate the switch to restore power to the fuel pump: turn the ignition on and off at least three consecutive times, after which it will be possible to start the engine.

Updated on 17 February 2026 by ScegliAuto

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