2018 Hyundai Sonata won't start, everything comes on when the key is turned but no starting action occurs

2018 Sonata SEL 42K miles

Lately it doesn’t always start even 'tho everything else comes on when I press on the start button. If I try a bit later, it starts fine. Do I need a new battery or is it the keyfob? I don’t think it’s covered by the warranty because it just passed 5yrs since the purchase.

You can try a new battery. Most fobs use a common CR2032 battery.

Or try this: (see page 5-13 of your owner’s manual)


If the good idea above doesn’t work, ask your shop to measure the voltages at the two starter motor terminals during a starting attempt. That should provide a clue to what’s wrong.

Just to add that five years on the original engine battery might mean it is time to replace that too before winter.


If you are the 1st owner, is it not still under warranty??

How long do Hyundai warranties last? This car is on the order of 5 years old. Is warranty still in effect at that age?

I have to say, that’s a pretty good warranty they offer. 10 years to original owner for parts & labor (I presume) for any problem that caused by a defective powertrain part. Seems like this would apply to OP’s problem, provided they are the original owner.

But 2nd buyer is cut in half to 5y 50K miles…

Seems like pretty good terms for the second owner too. I wonder if they classify the starter motor as a wearing part?

Unlikely the problem is a broken crankshaft, so the powertrain warranty won’t apply.

The new vehicle basic warranty is 5 years/60,000 miles. If the vehicle was sold before October 25, 2018, the warranty has expired.

The warranty for the battery was 3 years/36,000 miles.

The powertrain 10 year warranty only covers a broken crankshaft? hmm …a broken crankshaft seems a pretty unlikely event, so it seems the car owner has to carefully read the fine-print details of these long-term warranties, very carefully.

…and not rely on your interpretation of a powertrain warranty.

Normally… yes… However, I knew a guy who bought an Austin Marina circa 1976, and it suffered twice from a broken crankshaft. While both catastrophic failures were covered by warranty, the dealer took pity on him after the second crankshaft snapped, and gave him a decent trade-in allowance on a new Plymouth Volare (or, was it a Dodge Aspen? They were identical cars.)

As you might recall, the Volare/Aspen was perhaps Chrysler’s worst-ever car. After nobody could cure that car of its habit of stalling on the merging lane of the interstate, he dumped it and bought a used Caddy, which was actually a decent car.

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This reminds me of your problematic 70’s Volvo. On a recent podcast a mother of a college age daughter asks which used car to purchase for her daughter, budget $1500. Daughter wants a VW Microbus, but the only one available, its engine has a tendency to fall out … lol … Ray says this can be fixed, but the Microbus is too unsafe even if the engine didn’t fall out, so recommended a late 70’s Volvo for the daughter … Engine doesn’t fall out, has seat belts and pretty safe, solid body construction, but from what you say , this era of Volvo may not be particularly reliable … lol …

Not at ALL reliable!
Yes, Volvos were much more protective of their occupants in the event of a crash than other marques were back in those bad old days, but the number of electrical/electronic, fuel system, and mechanical problems were so numerous that I could only recommend that someone purchase a '70s era Volvo if he/she was an avowed masochist.

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We had a member whose fob battery died and he also could not open the doors because he had not tried the manual locks, if ever… Pull the door key out of your fob and make sure it still works, because all the advice and graphics that @Rainflurry provided are useless if you are locked outside your car…

If the key battery were dead, the ignition would not respond at all. If you fail to press the brake pedal hard enough, the ignition will switch to accessory mode, but the engine will not start.

My first car was a used 1979 Plymouth Volare. Piece of junk.