Originally Posted by wstar

You can't technically, reliably, refill the 7AT at home. The fill level is like most gearboxes/diffs: it's set by a fill hole level, you fill till the hole barely overflows. However, the Service Manual gives very explicit instructions that the fill level from that hole is only correct in a narrow range of transmission temperatures as monitored by the TCM, and unfortunately only the dealerships' Consult-III tool can see the temp numbers from the TCM.

In the real world, most likely it's pretty easy to get this close enough with an IR thermometer on the transmission's pan, but I haven't seen anyone with the right equipment or expertise confirm the correlation between pan temps and Consult-III temps, or confirm how precise the fill level really needs to be. GTM mentioned publishing some info about this once, but never heard back on it.

For the time being, it's better to have the dealership refill. It's not that expensive anyways. All things considered, I'll be swapping my fluid out every 20-30K miles just as an insurance policy. That's nothing compared to e.g. gas costs over the same timeframe, so it's just smart maintenance policy.