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Dead battery locks security system

My nearly new Hyundai Sante Fe sat in the garage for 18 days while I was away. On return the battery was dead. The auto assistance truck came to restart the car. His portable charger did nothing except make the emergency horn honk continuously while connected to the battery. We rolled the car back to the truck and hooked up to the big charger on-board. This, too, caused the emergency horn honking for several minutes until the key start worked. The explanation suggested was that the security system drained the battery, and that locked the security system. The dealer’s maintenance supervisor said “all new cars do this” and suggested I could disonnect the battery while it is parked for a “long time” and then reconnenct. Maybe, but what a hassle and what if you can’t open the electronic door lock to get to the hood release, to proceed. Is this really the state of things now?

“Maybe, but what a hassle and what if you can’t open the electronic door lock to get to the hood release, to proceed.”

You mean to say that Hyundai has stopped using key locks entirely? Is the ignition keyless too? ALL the ones I’ve seen have a key lock in the drivers door.

Yes! Anyone who owns a newer vehicle should read this.

You’re lucky you were able to get the vehicle to start! Some vehicles require a dealer scan tool to reprogram the computer so the vehicle can start when the battery is disconnected or goes dead.


Having this issue after a measly 18 days is ridiculous. When I worked for the National Park Service I was routinely sent away from home for 3-4 weeks at a time and my car would sit either at my work or in the airport parking lot, never did I have issues as you report.

Can you disable the security system while you are away for that long? I’ve never had an alarm installed in my car or come from the factory since most of the time they are only good for letting you know that; a) there was a loud thunderclap a second ago, or b) someone with a loud stereo just drove past.

Thanks for responses. The “tester” link is helpful, alarming, and discouraging. Not sure about the consequences of disconnecting the security system, but will ask dealer. (I agree it is a kind of false security nuisance.)

Does it not have a key operated lock on at least the drivers door?