Our n16 almera stalled at 30mph, the light came on so I got it on the diagnostic.. Standard dealer answer is timing chain so I stripped the engine myself. Ours was the crank position sensor needed cleaned. Fixed for £5 for a tin of electrical contact cleaner. If you know your radio code leave the battery disconnected a few hours/overnight to reset the warning light instead of getting fleeced for £30. I hope yours is something simple too. Try a reset and use proper contact cleaner on all the engine plug ins (wd40 is no good,the propellant stops good contact) or go the money for a diagnostic