Lexus RX Keyless Entry Malfunction

Sounds bothersome. Start by inspecting the door wiring harness where it passes from the body to the door. Repeated opening and closing can fatigue the wires. Also, inspect the plug connections for corrosion or damage. A loose or corroded connector can cause intermittent electrical problems. Have you checked the fuse for the locking system? Though, if it was a fuse, I wouldn't expect it to be only one door.

Thanks for the suggestions! I'm not very technically inclined, so how exactly would I inspect the wiring harness and plug connections? Any specific tools I might need, or precautions to avoid causing further damage?

Electrical work can be tricky without proper tools and knowledge. Given the error code and your discomfort with electrical troubleshooting, take your Lexus to a trusted mechanic for diagnosis. Considering your description and the stored error, the likely cause is a defective cable or plug connection, which can hopefully be resolved with a repair costing around 95€. This is better than potentially causing further damage or injury by attempting a repair yourself without the proper expertise.

Thanks so much for your advice! I brought my Lexus to the workshop, and you were spot on! It was a faulty connector in the door wiring, which they repaired for a reasonable price. Everything is working perfectly again now. I really appreciate your help!