Hi I have a qashqai 2011 and am having trouble with the red engine light coming on when I stop at traffic lights when I switch off the engine and start the car again the lights are off 

it only happens on tick over

if anyone has any idea’s I would be very greatfull

Thanks Alan…

The throttle body assembly may need cleaning, quite easy to remove and clean with Carb Cleaner and reinstall.

Alternatively, you can reset the Throttle with a scan tool and also worth checking the throttle pedal connections to ensure they are clean and secure

All of the above can affect the idle speed which may be what is occurring.