You need to escape the non-ASCII characters in your hardcoded URL as well:
//localisationName is a arbitrary string here
NSString* webName = [localisationName stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSString* stringURL = [NSString stringWithFormat:@"http://maps.google.com/maps/geo?q=%@,Montréal,Communauté-Urbaine-de-Montréal,Québec,Canadae&output=csv&oe=utf8&sensor=false", webName];
NSString* webStringURL = [stringURL stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSURL* url = [NSURL URLWithString:webStringURL];
You can probably remove the escaping of the localisationName since it will be handled by the escaping of the whole string.
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