sid, did you fix this? i have a similar problem with a kangoo van and renault are taking about a faulty receiver which is in the steering columb around the ignition switch. It apparantly "sees" the key and decides if it is the right one for the vehicle!
it can be either the ke or the sensor and only renault can test I have asked auto eklectricians but they say they can't help.
Originally Posted by SiD the Turtle
Thanks for the welcome! Useful stuff in the FAQ for the future.
I think I've narrowed the problem (hopefully) down to the key. Every battery I buy works okay for about half an hour then the led on the key goes really weak and the key only works with the central locking intermittently. I'm going to trundle down to the garage at the weekend and see about paying for another. It may not be the answer, but as the car only came with the one key I think I should get a spare anyway.