Method for controlling the functioning of two heat engines connected to a torque distributor (5) in a fire-fighting vehicle, each engine being provided with automatic transmission and with a first clutch (K1) connecting the first (A) of said engines to a delivery pump of a liquid; with a second clutch (K2) connecting the first engine (A) to the vehicle's traction; with a third clutch (K3) connecting the second engine (B) to the vehicle's traction. The control has an activation or a deactivation step of said delivery pump, by closing or opening said first clutch (K1) at a vehicle speed lower than a threshold higher than zero, and in a condition of decelerating vehicle, with the simultaneous opening or closing of said second clutch (K2), and if said conditions are verified within an interval of time from an activation or deactivation request.