2000 c5 key fob
 

i have 2 key fobs the #2 fob works fine the #1 fob will not hold memory i changed the battery it still will not hold memory first i tried holding the unlock lock keys in for 7 seconds the horn blows and it works but in less than 10 seconds it lost its memory. itried going thru the rest and option on the dash th reprogram the #1 and the # 2 fobs they both say progamed succesfully the #2 fob works great the #1 fob works once and then looses it memorry any ideas larry