I have a 639 vito with a 646 982 engine. The engine will not rev past 3000rpm-limp mode. Engine light is on and I am getting the following fault codes: boost pressure sensor signal is incorrect fuel rail pressure sensor signal pedal position sensor signal cyl 4 glow plug I have replaced the boost pressure sensor and rail pressure sensor signal with second hand sensors and the code still does not clear. I have tested the wiring for continuity to the cdi control unit plug.I have also checked for short circuits between the wires and earth and all tests ok. The engine harness is still stock and hasnt been tampered with. I am getting 4.9 volts to the boost pressure sensor and there is no voltage at the rail pressure sensor connector pins. Could this likely be an issue with the CDI control unit?