CPC replacement problem?

[JimT]

Sorry if this info is poor or wrong, but I'm posting for a friend who's out on the road.

Friend of mine has a 2015 Freightliner Cascadia, DD15 engine, 10 speed manual eaton fuller transmission. Late last week he had to get the TPS (Throttle position sensor) and CPC ("Common Powertrain Controller"?) replaced (say's it's also known as the PCM?). Anyway, he just messaged me saying that since the repair the engine won't go above 1100rpm's in first gear. Neural and other gears no issue. He's trying to get back to the dealer who did the work (he's in MA right now, dealer was in NJ), but I figured I'd throw it out here and see if anyone has any idea what or why this is happening.

No, he has no laptop/software. Doesn't do much work on his own truck, not demandated or tuned (that I know of). I have no idea what the issue was that led to last week's repair. But, i can relay any questions if needed.