2003 Sonata Keyless Entry

I read that after about 3 years the battery may need to be replaced. It will
be obvious when you have to press the lock button more than once. I replaced
the battery when I had to press the button more than once. Actually, I was
buying a Seiko watch and asked the sales person to replace the battery. Even
with a new Seiko battery, I still have to press the lock button several
times to lock the car. This isn't all of the time. But, maybe once every 3
or 4 times. I have noticed that it's more frequent after I walk through the
security sensors in malls. What do you think? Is this a conspiracy theory or
have you had problems getting the remote lock to work?
Thanks for reading,
John D.

 

First off, the Hyundai remotes have about half the range of the other
remotes. Second, many, many things can interfere with proper remote
operation.

That being said, it's possible you have a problem with your remote itself.
If the battery tests to 3V, it should be okay. If you think you have a
problem with your remote, ask the dealer to have a look at it on your next
trip in.

 

Thanks! You know, I didn't think about the remote... I was thinking it was
the receiver except that the trunk and open buttons work fine.
John D.

 

Why is that. My Sonata remote has longer range (100' at least) than my
Chrysler minivan. My Chevy truck don't use no steenkin' remote controls!

Matt

 

Wow! I've never seen a Hyundai remote even approach 100 feet before. It's
usually about 50 feet, tops, with an advertised range of 25 feet. Most
other manufacturers I've seen advertise the 50 foot range.

Obviously, the more powerful the transmitter, the better the range. Some
transmitters use two 3V batteries instead of one. I haven't opened one of
the newer-model remotes, so I don't know whether that's the case with them.


If you're in an area with strong rf signals, then you're more prone to
interference. I saw some poor technician try to diagnose a customer's
intermittently inoperative keyless entry over about three or four service
visits until he happend upon some papers under one of the seats with a
television station's letterhead. Turns out the problem only ever occurred
at work. Whaddaya know? I've heard some stories that there are areas in
southern Maryland where car remotes won't work for a few days. I'd
suspect this may be related to military testing. There were verified news
reports of people's garage door openers not working in Frederick, MD due to
military operations at Fort Detrick. Bottom line, these frequencies were
intended for military use, and these devices are simply allowed to borrow
the frequency when the military is not using it. The devices just operate
at a low enough power that they aren't strong enough to interfere with the
military uses of the frequency.

 

I get about 600' LOS range with my 01 Santa Fe's (annoying 2 button
remote). The 03's gets about 100' (more annoying 3 button remote).

Must be a little lithium cell? My Explorer used a 12v lighter battery,
they lasted years. One of my 01's has started to fade a bit. Should I
(can I) replace the battery or get a new fob?

What frequency do the key fobs use?

I've got all the ISM 915/2.4/5.3/5.8 spectrum in use here. Doesn't
appear to be any of those.

JS

 

I was in our church building one Sunday after services and the kids were
out by the Sonata in the parking lot. I was probably 25' from the
window of the church and the car was parked 75-100' from the church
building. I didn't figure it would work, but I thought I'd surprise the
kids by opening the doors and flashing the lights. I hit the button,
and the lights flashed and the doors unlicked. I haven't tried to find
the absolute max range, but I know it will do 100' all day long.


Matt

 

JS writes:
Must be a little lithium cell? My Explorer used a 12v lighter battery,
they lasted years. One of my 01's has started to fade a bit. Should I
(can I) replace the battery or get a new fob?"

If it's fading, try a new battery. There's a quite large chance that's
all the issue is.

Can't tell you what the specific frequency range is. I never particularly
cared what the range was, so I never tried to hunt it up.

 

Probably not the fob...
I found out yesterday that the door lock button on the driver's arm rest is
also intermittent...
It's a warranty problem!
John D.

 

Where is the remote located on the car? My remote key seems to be working but the car not responding.. Thanks