Hi Scotty, I have an 08 Yaris, 177,000miles, bought new. All maintenance done by me. The only thing I didn't do was change the ATF fluid. Like you say the owners manual says nothing about it. Rrecently, the check engine light has been coming on for a day or two then goes out and all is well. Twice now when the light was on the car wouldn't shift into 4th gear, even after it's warmed up. Fluid level is fine. The code says "knock sensor". Could that be why it won't go into 4th gear? It's too late to change the ATF fluid right? Maybe drain a quart out and put some "snake oil" in it? Change the knock sensor? The only other issue with this car was a dome light!
In term of P0XXX, what was the code that came out?
So, you haven't changed the AT fluid in nearly 200,000 miles? Why do you think there is a problem?
The OBD system wasn't designed to be a catalog of parts to change. There's no such diagnostic result that just says "knock sensor".
Wipe your ATF on a piece of white towel or paper and post a photo of it. Compare it to the ATF pictures in our FAQ.
