2002 Sonata: Cruise light on but Cruise Control won't engage via steering wheel

So this is a weird one. Just the other night I was on the highway
ready to use cruise control and found it did not want to engage. The
last time I remember using it was in late December or so. The Cruise
button to the lower-left of the steering wheel illuminates but when I
press the Set Coast button on the steering wheel I don't get the green
Cruise Control indicator next to the speedometer. I can't imaging this
being a fuse or something. Anyone got any idea what I should check?

 

Check your brake lights all around to make sure they are working properly.

 

My mother-in-law was tailing me to a restaurant today and noted I had
a couple lights out. If that IS it, it would be really, REALLY dumb
for Hyundai to have tied the circuit for cruise control to a
tail-light. I'll report back when I change them.

 

?

Not so dumb, many (most?) car makers do that including my previous Mercedes.
It is important to have the cruise control kick out when the brake is
applied.

What is dumb is to not have replaced those lights already. It can save you
getting rear ended.

 

?

Yes, having no working brake lights can prevent getting rear-ended but
come on...really? There are three sets of brake lights on my Sonata.
Whether your brake light(s) is out or not, it should not kill
functionality outright. It should still work regardless. It's the
functional equivalent to having a dash light go out and your a/c not
turn on until it gets replaced. Two of my three brake lights were
operational. The system should be designed such as to continue to work
in the event of a non-related function failing. It's dumb. Turns out
it was not a brake light, just one of the regular bulbs adjacent to
the brake light. Again, dumb. How many unscrupulous dealerships or
repair shops do you think would charge hundreds of dollars to "fix"
the cruise control because of this engineering intelligence lapse?
<shakes head>

- Thee Chicago Wolf [MVP]

 

Turned out to be one of the running lights. Thanks for the heads up.

- Thee Chicago Wolf [MVP]

 

I have to disagree. My Chevy pickup is wired such that a brake light
fuse blowing will prevent the interior lights from coming on. This has
happened a couple of times (I suspect from water getting in the trailer
hitch connector, but I am not sure) and I know know that no dome light
means no brake lights.

You can argue if the cruise control was the right choice and I would
have tended to pick something like interior lights as not everyone uses
cruise regularly, but having something obvious that quits working when
something less obvious, but important (brake or tail lights) quit
working is very intelligent engineering.

Matt

 

?

Think of it as nature's way of letting you know you have a light
malfunction. Thank an engineer for the thoughtfulness.

Not the same. The cruise control and the brake system are tied together for
safety reasons. AC is ties to nothing that will affect your life. It is
important that the cruise be switched off as soon as you hit the brakes.
Just ask any runaway Toyota driver

But they are related.


It's dumb. Turns out

Automotive electrical systems are rather complex these days. In many cases,
a switch no longer switches anything, but sends a request to the computer to
perform a function. I won't even guess what happens in that circuit.

How many unscrupulous dealerships or

It can happen, but it can also be a quick way to find out your lights need
work. Given that all the major auto makers use this type of system, perhaps
you should let them know you have a better idea.

 

?

I would not have put bulb out and cruise control not engaging
together. They are mutually exclusive to me. A fuse blow-out I would
have understood.

To me the brake system is the calipers/pads, rotors, and brake
pedal---not the brake LIGHTS. I understand 100% that cruise should be
triggered to shut off if the brake pedal is depressed. That seems like
perfectly normal safety behavior. Additionally, the Sonata has a
cancel button on the steering wheel. The cruise control and brake
pedal should be tied together. Yes, that makes sense. No cruise
engaging because a tail/brake light is out? No, dumb. Remember the
old school Christmas lights where if one bulb burnt out the WHOLE set
stopped working? Today if one goes out...ONE goes out, not the whole
string. It keeps on working because it's not in series but parallel. I
appreciate the debate but I just think it is not smart how it was
designed.

It's not a big deal to have a circuits dedicated to the bulb(s).

True but bulbs have to be on circuits for the same reason household
receptacles have to be on circuits. They are analog safety controls
done, I would imagine, in accordance to common electric wiring code
and standards to keep the system working in the event of a single
point of failure and prevent other sorts of overload or damage.

Save for those who change their oil themselves, most quick lube shops
let you know you have a light out. AT my last oil change I found out I
had a plate lamp out. I'm pretty meticulous with my car in terms of
replacing things at intervals and milestones.

Hyundai being a giant corporation, I would imagine they have elves
working the NGs. Perhaps simply displaying a console error message
when cruise is pressed in the event of a bulb burn-out that says
"Replace "___" Bulb To Fix/Re-enable Cruise."

- Thee Chicago Wolf [MVP]

 

?

They are mutually exclusive to you, but they are integrated to hundreds of
automotive engineer around the world. This happens on US and German cars
that I'm familiar with. No matter what anyone says, you are right and
they are all wrong.

While dumb to you, see above comment about engineers around the world.
Evidently (they think) they know something you don't.

Remember the

Frustrating when those tree lights go out, but they don't crash or run away
or apply power to any moving objects if they fail in any way.

That is possible and cars have had systems that tell you a light is not
working. That comes down to cost. What are you willing to pay for it?

 

It's not even that I am right and they are wrong. I just would not do
it that way because it doesn't make engineering sense to me. I don't
feel one needs to be an engineer to comprehend such a simple system
and my differing opinion is no better than the next guy. I don't think
any engineer is any more or less smarter than I am. I also do not know
if this a legal requirement by the NHSTA or some similar org to be as
it is. If it is, then F me because there's nothing I can do about it.
I went over my owners manual and didn't see any documentation of this
great "feature."

Whether one uses cruise control or drives with the accelerator
depressed to maintain a constant velocity for a prolonged period of
time, if a brake or tail light is out, it still poses *exactly* the
same danger of being rear ended. You do agree this is true?

If I am driving on the highway with my foot on the gas going exactly
60MPH or if I have cruise control on and I am going exactly 60MPH:
they are *exactly* the same thing. The driver behind me doesn't know
the difference. He will only notice I have no brake lights if he
suddenly starts closing in on me. I'm just saying that whether or not
a brake or tail light is out, cruise should still work. The person
driving the car should dictate if a function turns on or not, not a
light bulb. I mean, we now have the ability in some cars to turn OFF
our airbags. Do I think it's a good idea, hello no. But again, it's
there and under the full control of the driver.

- Thee Chicago Wolf [MVP]

 

?

Unless one of the engineers jumps in here and explains the reason, we'll
never know why it is done that way. Years ago, Jaguar used strange
electrical systems and fuse placement, but they were the only ones and
eventually came into compliance with common sense. Evidently, since other
use this system, there may be a very valid reason.

Yes, but cruising is not the question. It is knocking off the cruise when
you need braking. It is not necessarilyh done to prevent rear end
collisions, but to assure the "go" no longer works when you need "stop"

He may notice you have no tail lights (I'm sure that is what you meant) but
unless you apply the brakes, he won't know if you have brake lights. Unless
you apply the brakes, it does not matter.

It is not done to aggravate the driver, it is probably part of a redundancy
system to assure the cruise is not on when you need braking.

 

I'll do my best here. It seems the OP has a 2001-2006 Santa Fe, based
on his description of the switch locations. One of the features of
this vehicle is that it has an electronic LED center high mounted stop
lamp assembly.

The cruise cancel feature is accomplished by monitoring the brake lamp
switch output. When both brake lamps are burned out, this causes a
small voltage on the circuit, thus fooling the cruise control module
into thinking the brakes are applied.

 

Correction-- I see that the vehicle is a 2002 Sonata. Still, it has
an LED center high mounted stop lamp, so the same theory applies.