Err 01

[sparklie223]

So I have a canon 24-105L that I got from a friend. I'm now getting an err 01 message. Something about faulty lens connections. But I only get the error message when I use an aperture other than 4. Does anyone know how I can fix this?
Thanks

 

[unpopular]

Blow on the contacts...

Oh wait, that's for the Nintendo.

 

[Forkie]

I don't know much about Canon lenses, but do you need to lock that lens at it's widest aperture?