Skoda Rapid 1.6 2013 CAYC diesel, when you reach 4000rpm the engine light is on and it goes to 'safe mode'.
When you turn off the ignition and start again it is ok, until you reach 4000rpm then the same...

The errors are P0087, U1112 sometimes and P0090

Replaced with used parts the fuel pressure regulator 1, and the two sensors at the injectors.
Opened the hpfp and no metal found.

At the road, the real pressure of high pressure fuel is the same with the corressponding.

Is it possible that the pump at the tank will not working good?
The 16th pin of ECU it seems that maybe something has been blown (not sure)
Can we have an eletric diagram to see the purpose of the 16th pin of ECU?

What is your opinion?