Our 2001 key FOBS were on and off last year and when we left for FOT they just did not work. I asked the tech to look at then. Half and hour later he said he got one working, sort of, intermittently. He recommended a now control box and new key FOBs. Well I went back and checked the battery voltage, one was good, one was low, replaced the weak battery. Same level of performance. So I took them both apart again and checked the now 12 year old contacts. Quite a bit of green corrosion on the neg side spring, a little bit on the positive side. A good polishing with a pencil eraser cleaned them up. Reassembled them and now we have two perfectly functioning FOBs. Letters wore off long ago so I used a paint pen to make one button red and the other green.