Citroen C3 Transmission Fault

I encountered a similar predicament with my old Volvo V70. The symptoms you describe – engine failing to start, check engine light, and erratic gearbox behavior – resonate with my experience. Although the makes and models differ, the underlying cause might be comparable. What error code was stored? Have you noticed any correlation between temperature, humidity and the issues?

The error code points to a general transmission fault. I haven't noticed any pattern with the weather, but it seems to happen more often after the car has been sitting. What was the issue with your Volvo?

In my case, the diagnostic process revealed a defective transmission control unit. This resulted in comparable symptoms, including an inability to start the engine and shifting irregularities. The Volvo required a replacement of the affected control unit. Given your Citroen's symptoms and the error code indicating a transmission fault, it is plausible that the control unit is compromised. I would advise consulting a certified mechanic to conduct a thorough assessment of the transmission system. Be prepared for a repair bill in the region of 1000€.

Thanks so much for the advice. Sounds like I'm heading to the shop. I'll post what I find out.