what do i do if i cant turn key to start it and security lite is flashing?
on 2002 GMC Yukon XL 1500

i got in it turned key and it sounded like battery was low it clicked...then when i turned key to stop it i got out to open hood n tried to turn key again and key would not turn and i was jump starting it and security lite came on n key would not turn?

Wrong key used the second time or steering wheel needs to be rocked back an forth to take pressure off key cylinder while turning it.