Automatic Windshield Defogger Information?

[jda8]

Hi all. Just bought a 2009 Genesis 4.6 with Tech package. I assume that means it's fully loaded and has the automatic windshield defogger (it definitely has automatic windshield wipers). Anyway, tonight while driving the windshield got very fogged up as it was raining, and the front defrost never automatically came on. It was as if the moisture sensor wasn't working or wasn't detecting the fog/moisture on the inside of the window. I read and re-read the automatic windshield defogger section in my owner's manual but it didn't help me at all. Is the sensor and automatic defogger system always on no matter what?

I have a service appointment tomorrow for other matters. Should I ask the service department to try to check the sensor/system to make sure it's working? I even kept an eye on the screen to see if the air flow arrow ever changed to defrost on its own, or if the "auto defrost" icon ever showed on the screen, but neither happened. I just manually pushed the front defog button when needed. Meanwhile, the automatic wipers were working just fine. Advice please!

 

[shagnat]

Not sure about "automatic" defrost/defog. Maybe the "auto" button feature is what would take care of your issue..... but, I really don't know. I'll be curious as to the responses on this one.

 

[mikec]

If there is an upside-down plastic funnel/NACA duct shaped piece between the windshield and rear-view mirror then your car has the sensor for the AUTO defog function. When the A/C system is ON or in AUTO mode it may switch to window defog if/when this sensor deems it necessary. It won't detect the fog/mist that often builds up at the base of the windshield when you restart the car after it's been parked a short time - at least mine doesn't. When the system decides it needs to auto-defog, it pretty much won't let you switch to some other mode - it just blinks lights at you.

There is also an "override" procedure you can enter into the control pad to disable that blinking-at-you response:
1: ignition ON (engine need not be started/running)
2: Select the front windshield defrost ON via the "FRONT" button.
3: while holding the A/C button down push the air source button (the fresh-recirculate one) at least 5 times within 3 seconds.
The A/C display will blink 3 times in half second intervals when the sequence is recognized/accepted. Doing this sequence will kill the auto-defrost function, or restore it from a killed state. (and so will disconnecting the battery)

I don't remember the details on my 2009/V8 Tech - when the auto-defog kicked in. I just remember I hated it - and that I argued with the control panel on more than one occasion, getting that stupid blinking light response. I haven't seen it in a long time now so I probably did the override procedure (page 4-97 in the owners manual) long ago... I generally find most "auto" functions in cars don't work the way I'd like them to, or quietly switch modes without an obvious annunciation leading to "why are my feet suddenly getting warm?" surprises, so I rarely use auto settings.

mike c.

 

[jda8]

Well, I took my car to the Hyundai dealer yesterday for unrelated matters, and while I was there, I asked about the automatic windshield defogger sensor/system to my salesman as well as another salesman who is said to know a lot about the Genesis. Both of them told me that the system is designed to work when it is cold out, i.e. in the winter months, and not in the middle of summer when it merely rains and the windshield fogs up on the inside. One of them told me to have my climate control system set on "Auto" in order for the automatic defogging system to work, but again, it works when it's cold out. So, assuming that's true, I'll have to wait till winter time here in northern Indiana to see if the system actually works! But I sure don't mind waiting for winter to come.....

 

[WowCool]

What do you know! this morning (5am/Temp 64f) when I started my car I set the heat to 75f..And the Auto Defrost Activated itself..Never seen it before.
Usually I manually select my settings............

 

[DRS]

If there is an upside-down plastic funnel/NACA duct shaped piece between the windshield and rear-view mirror then your car has the sensor for the AUTO defog function. When the A/C system is ON or in AUTO mode it may switch to window defog if/when this sensor deems it necessary. It won't detect the fog/mist that often builds up at the base of the windshield when you restart the car after it's been parked a short time - at least mine doesn't. When the system decides it needs to auto-defog, it pretty much won't let you switch to some other mode - it just blinks lights at you.

There is also an "override" procedure you can enter into the control pad to disable that blinking-at-you response:
1: ignition ON (engine need not be started/running)
2: Select the front windshield defrost ON via the "FRONT" button.
3: while holding the A/C button down push the air source button (the fresh-recirculate one) at least 5 times within 3 seconds.
The A/C display will blink 3 times in half second intervals when the sequence is recognized/accepted. Doing this sequence will kill the auto-defrost function, or restore it from a killed state. (and so will disconnecting the battery)

I don't remember the details on my 2009/V8 Tech - when the auto-defog kicked in. I just remember I hated it - and that I argued with the control panel on more than one occasion, getting that stupid blinking light response. I haven't seen it in a long time now so I probably did the override procedure (page 4-97 in the owners manual) long ago... I generally find most "auto" functions in cars don't work the way I'd like them to, or quietly switch modes without an obvious annunciation leading to "why are my feet suddenly getting warm?" surprises, so I rarely use auto settings.

mike c.

Great post. Appreciate you posting the method to shut this off. When it is turned on, and the compressor starts, you know how things work on a gray day. The inside fog up once the compressor is shut off. Had this happen a few times already. I prefer when not in auto to control everything on the HVAC. Which includes not running the compressor much of the time.

 

[G-297124]

Good day. My heater works on my 2013 genesis 3.8lt sedan. But when I switch to windshield mode (defrost) I do not get any air flow to the vent for the windshield. Any idea to fix my issue. Thanking you very much.

 

[Gunkk]

Lots of these failures posted lately (must be winter time!).

The external temp sensor in front of the condenser, mode control actuator and heater mode control module are the places I would start a troubleshoot. If you can't DIY, then pay the best automotive electrician in your area $250 or so for a proper electrical diagnosis. Some diagnosis professionals may discount part of that cost into the fix if you proceed with them.