could damp or cold cause transponder problems?

For the benefit of anyone who may have (had) a similar problem:-
I am now convinced that my problem was caused by having 2 transponder keys in the van - the second one for locking the driver's door when leaving the engine running to defrost vehicle (which I know is wrong but sometimes "needs must"). I was carrying the extra key in my pocket and it was corrupting the code being transmitted to the engine management system which would not then unlock.

robert logan
December 2010