jumper between pins 4 and 13 of OBD2
start car.
P, R, D, R, D a few times
N, D over and over until D sticks (N doesn't show)
Shift to park. Keep engine running throughout
Disconnect jumper pins (important or idle speed might be incorrect)
While in Park, look at dash shift indicator for correct temperature
If no gear shown (it's blank), temp too low. Wait
If D is solid, temp correct. Drain excess fluid
If D blinking, temp too hot. Shut off engine, let cool down, try again.