2015 5.3 P0089 and P228C low fuel pressure

[AMPPPerf]

Hey everyone, I installed a blower on a 15 Yukon. Worked great up to 100 MPH. Then limp mode and low fuel pressure faults. GM dealer diagnosed bad HP fuel pump, pump has been replaced twice now. Now the truck idles for 10-20 seconds and sets P0089 and P228C. Limp mode. All wiring has been checked, service letter for the connector at the back of the intake has new pins according to the service letter. The customer is thinking he needs to tow it back to me, 2 hour drive, I'm trying to help the dealer tech try to figure out whats wrong. I cant see two bad pumps off the parts shelf at the dealer. Stuck for ideas??? Has anyone come across this? The coil for the FPR tests good, wiring checks out, now what?? Diver in the PCM? Problem is that it drove to the dealer just fine, now it won't barley move. Their scan tool show that the PCM is commanding fuel pressure, but only getting .5 Mpa. I'm out of ideas. Please help.

Thanks.

[Ben Charles]

Any tuning done??

[AMPPPerf]

yes, anything specific you want to know?

[Ben Charles]

If anything was changed in the fuel system tab, double check units on everything, HPFP I typically look at in Mpa... if that was changed could be simple as y it?s of measurement changed commanding the low Fuel output