Thought it was a dead battery

Hello, a few weeks ago our car wouldn’t start (2007 hyndaui sonota), we chalked it up to potentially leaving the lights on and got a jump. About a week later, I ran into a store came out and it seemed like the car had trouble starting- went to the next store, came out about 10 minutes later ,and it wouldn’t start. Okay- new battery time! So, i replaced the battery and all was great for about a week when it died again. I had it towed to the dealer and they said they weren’t sure, everything was fine (alternator, starter, engine etc) suggested a new fuel filter? (whih i have not yet replaced) So the pattern goes… If my car is on and off and on and off back to back it doesn’t start- if it rests for a good hour before being started again- it starts no problem. What is going on? Any advice would help. Thank you!!

Do You Know If The Dealer Checked The Car For Any Diagnostic Trouble Codes ? Did They Check For Technical Service Bulletins ? Has A “Check Engine” Light Illuminated ?

Don’t get too excited because I found a bulletin, but I can’t exactly relate it to the intermittent nature of your complaint ( doesn’t start . . . wait . . . starts).

Some 2006 & 2007 Sonatas have had problems with the signal from the Transmission Range Switch. Then the vehicles won’t start in “Park” or “Neutral”.

The bulletin tells Hyundai technicians how to diagnose this. Problems include corrosion on switch near gear selector, pinched wire in left windshield pillar, and maladjusted range switch on outside of transmission.

Does the engine try to crank over or is totally silent when turned to “start” ?

When it doesn’t start, try moving the gear selector to different positions, including “Park” and “Neutral” and see if it starts.

CSA

P. S. I should have explained that cars have these switches to inhibit their starting up in gear, which could be dangerous, but the switches / circuits sometimes keep it from starting in any position.

Great questions… i will have to ask the dealer… And thanks for bringing this to light for me, if it happens today (which i’m sure it will, lots of christmas errands!) while i twiddle my thumbs until it starts, i will try this. Still will have it checked as well… Thank you for the insight, i appreciate it… :slight_smile: