So I scanned a friends truck (60,000 miles 6.4 2009) that had P2291 low ICP and wrench light on also it was derating, would only go 10 MPH. I cleared the code and it ran good. I know there is a problem and the code is coming back. I have a scanner and can read the data stream. I've done plenty of 6.0's with their ICP problems but this fuel system is a little different than the 6.0. This is first 6.4 for me so I'm wondering what to expect.

 

Injection control pressure too low.

Check batteries, FUP sensor, wiring to the sensor or it maybe related the the HPFP.

Check the fuel filters as well. When were they changed last and were they OEM.