Lexus RC Transmission Torque Converter Fault

That sounds frustrating, and familiar. I had a similar experience with my previous vehicle, a 2016 Volvo XC60. The symptoms you describe – the slipping, grinding, and those lights – were almost identical. I was chasing ghosts trying to troubleshoot it solo. Did you check the transmission fluid level and condition? What error codes are you pulling?

I did check the transmission fluid, and it seems normal. I'm getting a code indicating a fault with the torque converter clutch circuit. Did the Volvo have the same error code, converter failure? What issues did you experience?

Indeed, the error code was related to the torque converter. Given your symptoms and the error code, it does sound like the automatic transmission converter is the most likely culprit. In my Volvo's case, it progressively worsened. Ultimately, I had to take it to a workshop. I would advise you to do the same; it is unlikely to resolve itself.

I appreciate you sharing your similar experience. It solidifies my suspicion of an automatic gearbox clutch problem. I will schedule an appointment with a trusted mechanic to assess the converter fault. Thanks again for your help!