[JacobeKenobi]

See Youtube link in attached text file since it won't let me post a link.

Does anyone have a clue what could cause this type of behavior? Every once in a while the alarm goes off when I try to start the car after being locked. Notice the strange pattern of the alarm sound. When this happens, the alarm cannot be stopped by turning the key, pressing the button on the key fob, or inserting the key in the door. However, if I lock the car, walk away for an hour or two and come back, the car usually will start up just fine. Other times, if I put the charger on the battery overnight, it will work in the morning. Other times, it seems like I can start it using the remote start button on the key fob.

Of course the stealership will happily keep collecting my money, but won't do anything to figure out what's going on. First they told me I had something miswired (which could only be their fault since no one else has serviced the vehicle). After they "fixed" that, I noticed that the tone of the alarm changed slightly when it beeps when locking the car. Not sure if that's related but seems like it could be. The next time I took it in, they told me I had a bad battery so I had them replace it, but it has since happened again several times. I have another appointment for it this week, but I'm hesitant to shuck out more cash for more BS answers. Any ideas?

 

[joegr]

I would measure battery voltage when it is happening. Maybe your alternator is failing, or the wiring is loose somewhere...

 

[DarrenBach]

Check for the dreaded poor chassis ground by the battery. :surprise:

 

[JacobeKenobi]

Thanks guys, will check those items. Another question, is this the normal sound my alarm should be producing? I've never heard anything quite like it. Is this what all Sonatas do?

 

[JacobeKenobi]

Hmm, think it could be the infamous hood switch? I "emulated" that scenario by locking the car while sitting in it, pulling the hood release, and sure enough, alarm goes off! However, this time when I unlocked the car and put the key in the ignition, it started up without hesitation. I wonder, though, if the problem lies in the alarm going off repeatedly for say, 2 hours, and draining the battery enough that the car won't start. Does that sound like a likely scenario?

 

[joegr]

.... I wonder, though, if the problem lies in the alarm going off repeatedly for say, 2 hours, and draining the battery enough that the car won't start. Does that sound like a likely scenario?

Seems possible. The suggested battery voltage measurement could reduce the guessing. (A good reading, 12.6V or higher, would likely rule this out.)

 

[avisitor]

If it is possible to have a small drain on the battery
Then the low voltage can possibly cause all sorts of weird things to happen
Would suggest looking at the battery voltage before starting??
How? Leave that up to your imagination.

 

[JacobeKenobi]

Problem solved. Faulty hood switch. Haven't had this happen again since fixing that.

 

[avisitor]

Problem solved. Faulty hood switch. Haven't had this happen again since fixing that.

Thought you tested it by popping the hood
The alarm went off but you could turn off the alarm with the key??

 

[JacobeKenobi]

Thought you tested it by popping the hood
The alarm went off but you could turn off the alarm with the key??

I thought I had proven that, but I discovered a key difference in how I was "emulating" the scenario. The no-start issue only happens if the hood switch gets released *and then pressed down again* before trying to start the car.

Edit: Also checked the battery voltage and it was fine.

 

[avisitor]

Thanks for the update