Please can anyone tell me how to reset the computer so no tyre fault comes up? I changed a flat tyre and there was a faulty monitoring valve that also need changing but the fault light still comes up on display. Mechanic has reset and diagnosed no error but light comes up. Display shows 3 tyre pressures but an arrow flashes on the one we replaced. Mechanic has checked and all tyres,monitoring and pressures are ok. No errors on diagnostics machine. Pls advise. Thanks George