Check Engine light at 36000 miles

My '04 Sonata hit 36,000 miles today, and when it did, my Check Engine
light came on (Not sure if it was exactly at 36000) When I noticed the
light, I had 36,003 miles.

Is this normal and will it go out on it's own, or is this yet another
trip to the Hyundai dealer, and if I do need to go to the dealer, is
it something that is covered under warranty?

 

It isn't normal. I don't know of any MIL code that is mileage based.
Something is amiss, but the only way to know is to read the code. Since
the car is under warranty, I'd suggest having the dealer read the code.

Matt

 

Did you recently put gas in your truck?

Chris

 

Definitely not normal. If it's something that's defective, it should be
covered by your warranty-- I cannot think of any maintenance related
issues that would cause the lamp. On the other hand, if the car has been
damaged in some way or you (or another person) did something that caused
the lamp to illuminate (such as leaving the fuel cap loose), the problem
wouldn't be covered by the warranty. Either way, if the problem goes
away, the lamp should eventually turn off. But, if you've not done
anything that could cause the lamp to come on (or if you're unsure), you
should definitely take it in. If it's warrantable, the dealer should be
happy to repair it and bill Hyundai.

 

If you recently filled up and then the light came on and otherwise the
car is fine. I would tighten the gas cap and give it a few days.

It's happened to me three times since Nov.

Chris

 

What part of installing a gas cap don't you understand?


Matt

 

I've never seen a car before where the Check Engine light was so
touchy.

Chris

 

Then you haven't drove a Chevy lately.

JS

 

I haven't drove one lately, but I've driven one lately. I drive a Chevy
quite often as I own a K1500 pickup. And I get Chevy and Pontiac cars
often as rentals on business trips. I've never had a light come on due
to the fuel cap. It really isn't hard to put a fuel cap on correctly.
If it is cross threaded, it is pretty easy to feel that. And the new
"quarter turn" caps make it even harder to get it wrong.

Matt

 

Loose gas cap causing "check engine" ??
what's next, cigarette lighter not properly pushed in???damn

 

It's been that way for a few years on almost all cars.

 

The gas cap is an emissions related item from the Feds perspective. The
cigarette lighter isn't, but should be! I'd rather smell gas any day
than a cigarette.


Matt

 

Those of us who know how to screw in a gas cap wouldn't even know that!

Matt

 

Which presumes that the rest of us don't? Here's to hoping you never find
yourself fallen prey to a simple mistake.

 

Sorry, but I just can't imagine being unable to screw in a gas cap
properly, unless you are 90 and have severe arthritis. And when the one
poster said he'd mess it up 3 times in a fairly short time span, that
is simply ridiculous.


Matt

 

A few months ago my extended warranty company rented me a Grand Am for
almost a week. The "CHANGE OIL SOON" light came on about 30 seconds
after starting the car, extremely annoying at night, and the oil had
just been changed (and was light and clear) before I picked it up.
Checked the manual, it explained how its a completely automatic sensor,
not just a mileage counter anymore. Guess its another piece of high
quality Chinese-built GM electronics.

(Now ex-)Girlfriend had a 95 Crapalier that she managed to wreck before
any of the GM dealers had even heard of Dexcool yet. They refilled with
normal green stuff... 20k miles later every 'soft' part in the cooling
system started failing repeatedly. Heater cores, water pumps, head
gaskets... Thousands of dollars pissed away in an entirely lousy
vehicle. Nobody wants to mention mixing dex-cool and regular antifreeze
makes a strong acid, they just "suggest against mixing due to
unpredictable performance". Is it any wonder why GM can't sell cars?

There are two Santa Fes in my driveway, an 01 and 03, with a total of
180k miles on the pair, and neither one has ever had the CEL lit except
for the normal flash when starting up. We've poured a lot of gas into
them over the years, so if it was anal about the gas cap I'm sure I
would have found out by now (I'm not the only one that pumps gas on
these cars...)

My 99 Dodge 1500 won't fire a CEL with a completely clogged cat and the
front oxygen sensor disconnected and sitting in the passenger seat
(absolutely clogged cat, drove 17 miles to the dealership that way, in
5th just a hair off idle it'd do about 37 mph). I've driven it >100
miles non-stop with the fuel cap off without the CEL going off... It
will throw a CEL if the fuel tank purge solenoid is disconnected, but it
doesn't throw a CEL if you disconnect the vacuum hose for the tank vent
or if the gas cap is left off. Very weird stuff...

JS

 

Hyundai's are notoriously touchy about having the gas cap not just
properly screwed back on but CRANKED.

Chris

 

Buddy

This has nothing to with properly screwing the gas cap back on. On my
'99 Hyundai Accent you have to CRANK the gas cap. Like 12 clicks or
the light will come on.

Chris

 

Have you tried a new gas cap? I've never heard of this before. 12 clicks
should not be getting you any tighter. The clicks you're hearing are the
cap slipping after it reaches its seat.

 

My Sonata has a built-in "clutch" so you can only crank it so far. Once
it clicks, you are done.

Matt