My transmission has shifting-problems. Sometimes it works well and sometimes it does not. Sometimes it just remains stuck in one gear and I have to turn it off, wait a while and then turn it back on. Sometimes it gives this strong 'jump' and then it begins working again but eventually the gear-shifting problems resurface. After experiencing this for over a year, eventually the band (chain) in the transmission broke-up and the vehicle had to be repaired. So I got the band replaced, the mechanic also checked the gears in the transmission and reassembled - but again I am still experiencing the same shifting problems. So the root of this problem is not yet determined. We don't know if it is actually the transmission or the computer or some sort of bad wiring sending wrong signals to the computer. Have you ever come across this concern with the NISSAN SERENA? Any suggestions?
It is possible that this is a transmission control module issue. As you may already know the transmission control module provides direction to the transmission as to shifting points, clutching and a wide variety of other control related transmission functions. Check to be sure there is a proper amount of transmission fluid in it. I would suspect that based upon your descriptions there is most likely a Check Engine Light on in your dash. This will register a fault code in the car’s computer which will provide detail as to the specific problems the transmission may be having. You will need a specific type of scanning tool that works directly with the transmission ECM rather than your car’s main computer. I would recommend having an expert from YourMechanic come to your home to diagnose your possible faulty transmission and make repairs.