Laguna Automatic Transmission Issue

I had something similar with my Laguna: slipping transmission and the light. Have you checked the hydraulic fluid level? It could be low and affect performance. Just a thought based on my own transmission problems. I'm curious if that makes a difference.

Thanks, I'll check the hydraulic fluid. But could undervoltage cause these symptoms? Was your issue voltage-related, or just the hydraulic fluid?

I didn't look into voltage much, but your symptoms match what I saw. Low fluid and pressure loss led to erratic gearbox operation. Voltage is possible based on the error, but if it continues, get it diagnosed at a workshop. Just my experience.

I checked and the low voltage was from bad earthings to the gearbox. Cleaned the connections and it's fixed. Cost 240€.