RX Transmission Oil Temperature Sensor Issue

Sounds familiar. I had a similar issue with my RX, though I can't remember the year. The symptoms you're describing, especially the rough shifting and error codes related to the transmission, definitely ring a bell. Have you checked the condition of the transmission fluid itself? Is it dark or burnt smelling?

Good shout! I haven't checked the fluid condition, just the level. Where's the best place to check it, and what am I looking for exactly? Is it a dipstick job, or do I need to get under the car?

On my RX, there wasn't a dipstick for the transmission. You'll likely need to get under the car. Honestly, if you're seeing those symptoms and suspect low fluid plus a bad sensor, I'd strongly recommend taking it to a workshop. Messing with the transmission without proper tools or knowledge can be risky. They can properly diagnose the issue and replace the sensor.

Thanks for the advice! You were spot on. Took it to the workshop, and turns out the gearbox oil level was indeed too low, plus the temp sensor was kaput. 365€ later, she's shifting like new. Appreciate the help!