Peugeot 508 Hybrid Automatic Gearbox Problem

That sounds familiar. I have a 508 too, though not the hybrid. I had similar symptoms a while back - slipping, grinding, and the lights on the dash. Was it diagnosed as a torque converter issue? What codes are you getting?

Yes, the error points towards a defective automatic transmission converter lock-up clutch. I haven't noted the exact error codes, but the diagnosis strongly suggests the torque converter is the culprit. Did you experience similar issues with the torque converter, and what was the solution in your case?

Confirmed. It was indeed the torque converter. It started subtly, but quickly escalated to the point where the car was almost undriveable. I ended up having the entire converter replaced at a workshop specializing in automatic transmissions. There's really not much you can do yourself beyond confirming the diagnosis.

Thanks for confirming. I suspected as much. It's booked in at a workshop; they've quoted 2120€ for the repair. Appreciate you sharing your experience.