Trajet automatic transmission issues

I had a similar issue with my Trajet a while back. It sounds like the transmission is not correctly registering that it's in Park or Neutral, hence the no-start condition. The slipping could also be a symptom of the same problem. Has the check engine light just come on, or is it flashing at all? How unclean are the shifts?

Thanks for the quick reply! The check engine light is constantly on, not flashing. The shifts feel jerky sometimes, especially going from 2nd to 3rd. Could a faulty transmission sensor cause all these symptoms? I'm trying to figure out if it's worth trying to replace the sensor myself or if I should just take it to a mechanic.

Yes, a faulty transmission sensor can definitely cause all those symptoms. It's possible the sensor is sending incorrect data to the control unit, which is causing the shifting issues and preventing the engine from starting in Park. Honestly, given the error code and the other symptoms, it does sound like the control unit itself could be defective as suspected. This could be causing issues with the sensors and shift solenoids. In my case, it turned out to be the control unit. I recommend taking it to a reputable workshop for diagnosis. In the end my transmission repair cost about 1000€.

Thanks a lot for sharing your experience! It's really helpful to know that someone else has dealt with a similar issue. I think I'll take your advice and bring it to a workshop to avoid further damaging something. I'll post the diagnosis when I get it.