[KiwiME]

Your advice here seems to be what pretty much every web source recommends for cars in general. Odd that the I5 manual specifically states the opposite order (i.e., EPB last) -- who knows if there's an actual good reason behind this or if it's just careless writing?

After another two hours googling main brake and EPB videos and writeups, I guess my only remaining curiosity is whether or not the I5 EPB is doing its braking via the very same disc brake pads as the main brake system. Apparently the same pads, disc or drum, are activated by both the main and parking brakes in some but not all cars via different activation mechanisms? If they are, then I can see (exactly as you said) that it really makes no difference whether you hit the EPB before or after entering Park mode assuming that you've got your foot on the main brake pedal throughout the whole procedure.

I can see why they recommend Park then EPB, it's logical from a vehicle controls perspective but arbitrary as regards safety. By flipping them around you're reducing the chance of a clunk noise that I think every driver of any automatic car has experienced when shifting out of park on hill.

I believe the EPB on the Hyundai EVs is done by acting on the pads from the back side of the caliper, opposite the hydraulic cylinder, with a motor-driven screw.

 

[rbdavis808]

I believe the EPB on the Hyundai EVs is done by acting on the pads from the back side of the caliper, opposite the hydraulic cylinder, with a motor-driven screw.

Thanks! So then, both EPB and the main brake pedal are using the same rear disc pads, right?

 

[KiwiME]

Yes

 

[rbdavis808]

Very useful to know, thanks!

 

[harshaw]

One thing that is interesting is that for an ICE car with an E-brake, that will mean rear wheels don't turn. However, you also have the engine with the front wheels (thinking of my previous manual transmission car) which also, when left in gear, means the front wheels don't turn. Thinking about this some more - with ICE cars Park means the tranmission is in park so the wheels can't move. But in the ioniq5 (and other EVs???) this has no meaning, so you rely on the brake being engaged - and if that is only the rear wheels, that isn't good enough in some circumstances (although likely rare, I just happened to create one).

I wish I had a video but the explanation that the rear wheels were locked but the front was not would line up with why once the car was turned off the car slid.

 

[Pontanius Black]

One thing that is interesting is that for an ICE car with an E-brake, that will mean rear wheels don't turn. However, you also have the engine with the front wheels (thinking of my previous manual transmission car) which also, when left in gear, means the front wheels don't turn. Thinking about this some more - with ICE cars Park means the tranmission is in park so the wheels can't move. But in the ioniq5 (and other EVs???) this has no meaning, so you rely on the brake being engaged - and if that is only the rear wheels, that isn't good enough in some circumstances (although likely rare, I just happened to create one).

I wish I had a video but the explanation that the rear wheels were locked but the front was not would line up with why once the car was turned off the car slid.

A RWD ICE car would also have the front wheels rolling freely once the car has been parked.
This isn't really a thing with EVs. More like a problem with standard configuration of RWD cars.

FWD cars usually has the parking brake on the rear wheels and you can use the gearbox to stop the front wheels.
Although, some manufacturers have in the past experimented with parking brakes on the front wheels. With how we don't really see that anymore, I'll let you imagine how succesfull it was.

Also.. There is video out there of a Tesla deciding to do a little excursion on an icy driveway, much like your I5 did. So really not a problem for the I5 specifically.
I'm thinking it's more a problem with slippery, sloping driveways in general.

 

[rbdavis808]

Although, some manufacturers have in the past experimented with parking brakes on the front wheels. With how we don't really see that anymore, I'll let you imagine how succesfull it was.

OK, I'm dumb enough to ask: why is it a bad idea to have the parking brake on the front wheels?

Naively, it would seem that having the pawl on one axle and the parking brake on the other is the easiest way to lock all wheels. I've been trying to imagine how this might put more stress on the pawl, but I'm not coming up with anything (assuming that one always depresses the brake pedal, engages the parking brake, and then engages the pawl).

Alternatively, why not have the parking brake lock both axles? If, like I5, the parking brake is electronic and it activates the existing main disc brake pads, seems like it wouldn't require much additional expense or complexity to activate all four disc brakes.

Very likely there are good reasons why both of the above are terrible ideas, but they are well beyond my dim understanding. 😀

 

[Pontanius Black]

OK, I'm dumb enough to ask: why is it a bad idea to have the parking brake on the front wheels?

Naively, it would seem that having the pawl on one axle and the parking brake on the other is the easiest way to lock all wheels. I've been trying to imagine how this might put more stress on the pawl, but I'm not coming up with anything (assuming that one always depresses the brake pedal, engages the parking brake, and then engages the pawl).

Alternatively, why not have the parking brake lock both axles? If, like I5, the parking brake is electronic and it activates the existing main disc brake pads, seems like it wouldn't require much additional expense or complexity to activate all four disc brakes.

Very likely there are good reasons why both of the above are terrible ideas, but they are well beyond my dim understanding. 😀

You could have the epb work on all four wheels. It's just expensive and really uncalled for in most instances.

Friend of mine's younger brother had a fench car with parking brake on the front disc brakes.

One warm summer day, he went for a drive, parked back home on a steep city street. Pulled the hand brake and left.

Brakes cooled over time and brake loosened and car rolled down the hill and crashed into a parked car.

Always makes me laugh when he tells that story.

Mind you, rear brakes also heat up, but front brakes takes the brunt of it all.

Never once seen a car with parking brakes on the front wheels, only heard of them. That's how rare they are.

Regarding the pavl on the gearbox, mamufacturers claim it can withstand just about anything, and yet we sometimes see them fail. Personally, I've always used the parking brake when putting the car in P.

Except when I drove a Mercedes taxi.. but that's because their parking brake system was stupid from A to Z, and would often disintegrate from not being used.

 

[rbdavis808]

I drove taxis too for a few years, but weren't none of 'em Mercedes! On most (usually Plymouth Volare) the steering wheel would free-travel 20 degrees in either direction before the front wheels would start to turn. Fun times!

 

[Pontanius Black]

LOL!
The old Mercedes had a similar tendency because of the steering box they used instead of rack and pinion steering.
Old tech just wasn't as precise, and so the law allowed for more play.

Problem with the parking brake was, you engaged it with a pedal. But the pedal was situated a bit high, so it was troublesome to engage it with your foot. And disengaging it was with a handpull.

The mechanism itself was a drumbrake inside the center of the brake disc, and it would seldom get used or heated through, so it attracted moisture and would often decay from rust.

Seen these discs get pulled off and just bits of rusty metal falling out.

Not a fan of that design.

 

[cmwade77]

Just so you know, the parking brake automatically engages when you put the car in park and turn it off. This is assuming you have all updates and recalls performed of course.

 

[rbdavis808]

Just so you know, the parking brake automatically engages when you put the car in park and turn it off. This is assuming you have all updates and recalls performed of course.

As far as I can tell this is not true for our 22 RWD. When I explicitly apply the EPB prior to shutdown, two things happen: (1) I immediately hear noise (EPB motors?) for a few seconds as the EPB is applied, and (2) after turning off the car and later restarting, the red EPB icon in the lower right corner of the instrument cluster remains lit until I either put the car in gear or release the EPB. When I do not apply the EPB prior to shutdown, (1) there is no EPB motor (or whatever) noise before the car turns off, and (2) said EPB icon does not remain lit for more than a second after the car is restarted.

I'm very annoyed that there seems to be no way to know either what updates (other than infotainment) have actually been applied to the car or what updates (other than recall-level) are available for the car. I specifically told the dealer at purchase to make sure the parking brake recall update was present before delivery and they told me it was, but I have no way to verify. It sounds like a bunch of other stuff was bundled into the recent pre-con update, but as our car is RWD it's never going to get that.

 

[cmwade77]

As far as I can tell this is not true for our 22 RWD. When I explicitly apply the EPB prior to shutdown, two things happen: (1) I immediately hear noise (EPB motors?) for a few seconds as the EPB is applied, and (2) after turning off the car and later restarting, the red EPB icon in the lower right corner of the instrument cluster remains lit until I either put the car in gear or release the EPB. When I do not apply the EPB prior to shutdown, (1) there is no EPB motor (or whatever) noise before the car turns off, and (2) said EPB icon does not remain lit for more than a second after the car is restarted.

I'm very annoyed that there seems to be no way to know either what updates (other than infotainment) have actually been applied to the car or what updates (other than recall-level) are available for the car. I specifically told the dealer at purchase to make sure the parking brake recall update was present before delivery and they told me it was, but I have no way to verify. It sounds like a bunch of other stuff was bundled into the recent pre-con update, but as our car is RWD it's never going to get that.

My car is a 2022 RWD as well, I never set my emergency brake manually.

This is what it looks like when I get back in my car and the car was on for a few minutes.

And yes I hear it engage when I turn the car off as well.

 

[cmwade77]

I also just checked, it doesn't matter if I put the car in park or not, it always engages.

 

[rbdavis808]

My car is a 2022 RWD as well, I never set my emergency brake manually...

And yes I hear it engage when I turn the car off as well.

Interesting, clearly different behavior than mine. Sure wish there was a way to reliably determine installed vs. available updates other than just trusting your dealership.

 

[cmwade77]

Interesting, clearly different behavior than mine. Sure wish there was a way to reliably determine installed vs. available updates other than just trusting your dealership.

If I recall correctly, there is/was a setting somewhere in the infotainment system for this.

 

[rbdavis808]

If I recall correctly, there is/was a setting somewhere in the infotainment system for this.

I've looked to no success (other than finding the infotainment release).

There are threads here on accessing an engineering mode via magic touches and passwords, but I don't recall anything there that listed installed driving revs.

 

[alexw]

A somewhat overlooked point in this thread: it goes to show that the stock tires are optimized for EV efficiency and not at all cold weather performance. Having myself slid sideways at 0mph on a banked curve a few weekends ago, try to remind yourself frequently: AWD doesn’t mean “king of the snow” - you need winter tires for that title. Get some traction devices if you plan to drive in such conditions too infrequently for winter tires.

 

[Wrenching Fool]

A somewhat overlooked point in this thread: it goes to show that the stock tires are optimized for EV efficiency and not at all cold weather performance. Having myself slid sideways at 0mph on a banked curve a few weekends ago, try to remind yourself frequently: AWD doesn’t mean “king of the snow” - you need winter tires for that title. Get some traction devices if you plan to drive in such conditions too infrequently for winter tires.

That goes for any vehicle on the road, EV or otherwise. Anything other than winter tires or chains in snow/ice should be criminal.

 

[KJ4cars]

My 2022 SEL AWD did this twice on my sloped driveway. Once it was icy. Once it was dry. Got software updatess two weeks ago and they set it to have parking brake go on automatically. Not convinced it's fixed, because got the battery preconditioning update at the same time and that didn't work on my recent road trip.

I experienced a curious event this morning. In the northeast we just had a big snowstorm. This morning I cleaned off my driveway with the snowblower and, as it happens, there is some amount of slush / snow left on the driveway. My driveway slopes up out of garage to the street. I moved my Ioniq5 out of the garage and parked it on the slope of the driveway.

When I moved the car onto the driveway - I put it in a park and the car just sat there. I turned off the car and started to get out - it started sliding down my driveway towards my garage! I quickly got back in the car. Luckily the slope isn't that bad that it was going to hit my garage or house. I tried the experiment again. I drove up the driveway a little bit, put the car in park, and put on the emergency brake. When I turned off the car - again - the car slid down the driveway.

My only thought is that the car was idling every so slightly, and when the car was turned off, the pressure against the wheels went away and the car slid down the driveway.