AC motor controller on it?
pretty sure its a motor controller overheat code

Status Code 41
Traction Motor Controller Overheat

- Pushing or pulling loads can be a cause for overheating the controller
- Stalling the motor too long
- Not enough heat sink grease between controller and heatsink panel.
- cooling fans not operational (if any are installed)

Make sure on this controller model, there are other trucks in this range that have EV100ZX, SEM controllers and EVT100.