What's the mercedes Sprinter fault code 43c0?

Code 43c0 in a Mercedes sprinter means that the voltage supply is too low. It's often associated with the pump power supply. Check fuse F4 40 amp. These are known to blow.Remove the fuse from its holder. In some cases You may need a small screwdriver to unscrew the fuse holder cap. Look at the fuse wire. If there is a visible gap in the wire or a dark or metallic smear inside the glass then the fuse is blown and needs to be replaced. Many local parts stores such as Advance Auto Parts and Auto Zone carry a wide variety of fuses. Just make sure to match the correct amp and size fuse that You are replacing.