Lexus GS transmission control unit failure

Sounds rough! Slipping and grinding isn't good news, especially with the error code. Has the maintenance been kept up on the transmission? Fluid changes on time? When the paddles stopped working, did it happen suddenly, or was it gradual? The emergency mode thing makes me wonder if it's a deeper electrical issue affecting the transmission control. Honestly, it sounds like the car computer might be at fault.

Yeah, it's pretty bad. The fluid changes were done as scheduled, so I'm not sure what's going on. The paddle shifters failed suddenly without any warning. The car computer, you mean the transmission control unit? Is that a common problem with these?

Okay, fluid changes being done is good, rules that out. Sudden paddle failure points even more to electrical/control unit. And yes, I mean the transmission control unit – basically the computer that tells the gearbox what to do. I've heard of similar issues with other cars, but I don't know if it's common for the Lexus GS specifically. Given all the symptoms, it might be best to get it checked at a shop. If the affected control unit is defective, you should replace it. It will cost around 1000€, but it should solve all your problems. Better safe than sorry with transmission problems.

Thanks a lot for the help! I took it to a mechanic, and they confirmed it was indeed the transmission control unit. They replaced it, and now it's shifting smoothly again. Cost me about 1000€, but it's running great!