We had this error P0748 come up on the Doblo whilst en route to Solfest, The car was in restricted performance so was not good. At solfest I found the Bluetooth Elm in the car and it returnded the P0748 code, I had limited internet but the code related to gearbox solenoids , It’s Manual?
Without proper internet I could not delve deper , even when I got home and advanced searches I could not find a sensible answere
Fortunatly we had bought MultiECUScan to do a DPF job. And that gave more helpful information.
P0748 Fule capacity regulator ( High Pressure Pump Inlet )
However, even searching this is likly to draw a blank.
But I had replaced the HP Pump as part of a starting issue, and knew there was an electronic feed to it. Low down on the right of the pump is a 2 wire connector. Looking at it, it looked a little loose and I did my best to try and re-fit it. And the code went away and the power came back! Simples I had not done the job well enough on he replacement. It occured again a week later so I took out the battery and realy so I could remove and get better purchase on the connector, and a squirt of contact cleaner for good measure.