my 2005/2006 Ford focus hatchback car developed a stalling, jerking and sudden stop problem for 3months now. I have changed the spark plugs, ignition coil, fuel relay, used 9fuel pumps, changed slow jet, changed air collector, used 2 fuel pump casings, inner & outer fuel filters and changed the brain box all to no avail. I have also washed my fuel tank from clogs. Diagnosis displayed error code PO230. Please, what could be the possible element that reduces voltage to the pump thereby damaging it 20 minutes after installation/change. Thanks
You need to check the fuel pump relay, as well as the inertia "crash" switch in the rear of the vehicle. Those are the likely things that can cause a P0230 on a Ford focus.
The only other possibility is the crank shaft sensor, which pulses the ECM and causes the fuel pump to be kept "live" and running. I doubt the problem is here, as the vechicle would not run well at all with a failed CPS crankshaft sensor. While it's possible this sensor is overheating and causing the problem, I would look at the fuel pump relay and inertia switch first.