Random shutdown

[KME625]

2016 Expedition XLT EL. It will randomly shutdown on hot days. Usually 85 or higher. I can't find the exact codes it sets but they're for the fuel pump. The HP and LP pumps have been replaced as has the module. The 2 common denominators seem to warm ambient air Temps and AC on. Never happens on 80 or lower days. Can go months without it happening. Mechanic is tired of looking at it because it can't be replicated and doesn't have real time data. I'm ordering a Blue driver to be able to get real time data. Does anyone have any suggestions what to look for in the meantime? I feel like something electrical is failing when it gets hot. It also drops from 6th to 4th right when it starts to happen.

 

[Dennis_H]

Don't know the wiring for sure, but I had an old Honda that did the same thing with its fuel pump relay. Had bad solder joint internally that would open up when it was too hot outside and it had been sitting in the sun. Had to open doors and let it cool down and would eventually cool down enough to start. (Relay was under dash) Sounds similar and maybe there is a relay or module not allowing current through?