Ive got an 08 ext that every once in a while the smart key wont open doors. Ill skip to the chase. If I open the hood and disconnect and the reconnect the battery every thing works fine, and yes its a new battery, and yes the connections to the battery are clean and tight. It seems like a relay is stuck closed and when the battery is disconnected and reconnected the jolt from the reconnection opens a relay and all is good. This seems to happen once a month. I have noticed that leaving the heater on when I tern the car off has been one symptom that I have notice when the problem reoccurs. however don't know if its linked. if I turn the car on no power to anything at first. If I cycle the key on and off and on and off some of the lights on the dash will start to come on but never will allow the car to start. until the battery is disconnected and reconnected. Ill save the embarrassing commits about the GM junk. I will say I miss my stolen 03 ford f150 Harley Davidson. HELP.

 

there should be code(s) stored. you will need to go to GM dealer to find out what they are. You could try auto parts store free scan but they only scan pcm. code could be in different module

 

Thanks slowroll. I will try this. When it dose it, I never have the time to allow the car to be towed to the dealer. I've been trying to gather information so I can try to explain it to a tech with as much info as I can. intermittent problems are the worse. hard to fix something that isn't broken when you take the car in. Again thanks for your time.

 

Hi shackallic,

Looks like you got some good feedback from slowroll already. Let us know how things go, and if you need additional assistance don’t hesitate to reach out to us.

Austin J.
Cadillac Customer Care