I need to disconnect by battery on my focus,but reading the manual,it says about losing the data in the ECU?and then having to be re-programmed.Does anyone know if this is true.I have a T reg focus.Thanks
Some of the older cars with the aldl system had volatile memory. You had to keep power on the system or it had to be towed to a dealer for reprogramming.
Most of us made a unit from a lighter plug and a transistor battery. Plug that into the cig lighter and then disconnect the battery. It was enough to prevent a dead computer. Newer cars do not require this.
That is the case if you disconnect it with the engine running or maybe with the ignition on.
Disconnect with ignition off and you will have no problem. car batteries have to be disconnected regularly for various reasons throughot a cars life. If the ECU needed reprogamming everytime it really would be a big pain in the proverbial
