Unable to lock car, as red warning light always on?

Red warning light on dashboard is nearly always on, even when driving my Kangoo Dynamique along the road,alarm also sounds. When I park, I'm uable to lock car at all, unless I'm lucky and can catch a moment when the red light flickers out. This car is a 2010 model - I'd change it for a new one, but Renault no longer importing Kangoo cars, and it suits my lifestyle particularly well.