Rear fog light/body control module issue - Scenic II 2004

Hi,



Hoping someone has experience of this!



Failed MOT on rear fog light not working, switch works (indicator on dash lights up), bulb is fine, bulb holder terminals and multiplug terminals are immaculate so not an earth problem.



I only get 6v at bulb holder when measuring across terminals, with bulb out. When you insert the bulb and measure again it drops to nothing, tried another buld to check this, the same.



I have traced the wire back to the body control module behind the glovebox, where the wire comes from the BCM I have measured the voltage again. I get 6v (7v when engine running, so giving half of power in to power out) when switching rear fog on, and still get 4v when it is switched off!



So I guess the BCM is the faulty item?



For MOT the rear fog indicator on the dash must come on with the rear fog lamps, so I cannot simply rig up a separate switch as it needs to control the bulb and the dash LED too. Bugger.



Biggest question...If I purchase a new BCM of the same part code, can I simply swap them out? Or will they have to be "coded" into the car?



Thanks



Jamie