Originally Posted By: mva
The reason I asked is that I couldn't find anything in the manual on how to check cold or hot.
I just did a drain and refill (the Sienna has a drain plug on the tranny and recommends changes every 48,000 km).
Although the manual says nothing about how to check the level it does give the volume for a drain and fill as "up to 3.5 litres".
I drained it hot, added 2.6 litres and it showed at the bottom of the "hot" range (with engine idling) after a good drive to warm it back up. This morning I checked it before starting the motor and it read full on the "hot" range. I started it up, went for a short (2 km) drive and checked it with the motor idling and it read at the low end of the "cold" range. So I added 0.4 more for a total of 3 litres, started the motor and now it reads at the top of the hot markings!
I still need to take it for a longer drive and check again.
As part of the drive to warm up the tranny, make sure you go through every gear for 10 seconds including reverse. Every path needs to be filled with ATF to get a good reading.