Okay so there's a series of test modes in the Cmax Hybrid I've discovered from browsing here and experimenting on my own, but none of them seem to accomplish what I'm looking for.
What I have found is the basic engineering test mode where you hold the left OK button on the steering wheel down when you start the car and hold it until the menu pops up on the left display, and a couple of engine test modes.
From what I can tell there are 3 engine test modes you activate the exact same way but using 3 different gears in the gear selector.