The invention relates to a cleaning system suitable for being mounted on a motor vehicle and comprising at least one first and one second cleaning devices, each cleaning device comprising a cleaning liquid reservoir, at least one cleaning nozzle for spraying the cleaning liquid, a fluid distribution circuit arranged to convey cleaning liquid from the reservoir to the cleaning nozzle and a pump arranged to inject the cleaning liquid contained in the reservoir into the fluid distribution circuit, the cleaning system further comprising a bypass device connecting at least two cleaning devices by their respective fluid distribution circuits, comprising a backup line and a solenoid valve placed on the backup line, controlled as a function of the failure state of a pump, and arranged to supply the cleaning nozzle of one cleaning device from the reservoir of another cleaning device, each cleaning device comprising a non-return member between its reservoir and a point of connection to the bypass device.