How do we know if it's low? Pull the dipstick and check. sheesh, LOL.
It could be, but it seem more times than not when a trans is low it wants to slip.
It could be that the fluid is that dirty and a solenoid is sticking or the torque converter isn't unlocking. Again, both could be caused by dirty fluid.
Happen to be any pending codes?
Is that an easy replacement or better for a shop?I had this once, my check engine light eventually came on and gave me a code (don't remember the exact one) but it told me the sensor that feeds back gear selection information to the BCM was faulty.