By the sounds of all your problems, it is the Pressure Sensor that has gone, which is a common fault on Scenic Aircon systems.
Renault quoted me £142 to supply and fit the part, but I will be fixing myself as it is just a case of taking off the plastic engine cover underneath, locating the aircon tubes and unscrewing the part and putting the new one in.
The guy who was quoted around £800, don't pay it! They are ripping you off!
The guy who said Heater setting 4 doesn't work, this is another known fault of the Scenic. It's a connector that needs replacing which, although a bit fiddly to change, can be done by yourself. It's located behind the tiny storage space infront of the steering wheel, next to the dash layout. That cubby hole pops out and you can see it from there. Change the connector and away you go.
For great advice on Scenic's you can go to www. renaultforums.co.uk as there is a mind of useful information on that website.
Anyone had the light disappear where the heater controls are? Renault want £200+ to replace a circuit board behind the controls to illumiate everything again. It takes 5 mins to take everything off so you can gain access to it!
Don't believe everything Renault tell you. I've just changed the EGR valve as it was causing no end of problems on my 4-yr old Scenic with 84k on the clock. Was quoted nearly £300 to replace it. A Renault mechanic replaced it for me in 30 mins for £45 plus the part cost of £100. Renault quoted 2.5 hours to repalce it!
The garage is targeted on costs, not on the service they provide you. Remember that when they try to charge to £850 for an aircon system when it's probably the pressure sensor that is faulty!
www.breakeryard.com will supply you 2nd hand parts at very reasonable prices!
All that glitters is not Renault! lol
Hope all that information helps!
Steve Mason, January 2009