Charger door won't open

I understand that Brendon Foot did check with Hyundai NZ to see if the repair could be done at no charge even if out of warranty but evidently not. However when the car was in the workshop they applied a "recall" to recalibrate the BMS to more accurately show the range remaining. I asked if this would also apply to the 2021 Kona and yes it does, so the car is booked in for that in January. I was also told that there was a warranty recall on that car to change the battery coolant because of crystallisation issues reported overseas, and that would be done free - it takes three and a half hours. Will keep an eye out for the coolant colour!

 

That is an advantages of your early example with green coolant, no blue coolant problems or expense to replace. The blue coolant issue has been around for about a year and they perhaps could have been a bit more prompt about notifying you as it can clog up expensive parts. There's a Niro owner on Reddit that reports both the traction battery and inverter have needed replacement. However, the good news is that the next replacement interval should be extended to account for the coolant being renewed. Most reports say that it takes longer than the time they quoted you, generally overnight.

The BMS update may be the same one that has also been around for while to fix an issue with charging. I asked about this for my own Oct 2018 a few weeks back and was told there is none. I suspect if I call now the answer will be different.

 

I've pried it apart, and can see how it works. There is a motor with a worm on its shaft that turns a quadrant that moves a rod up into the plunger "ball point" shaft and locks it. I'll see if I can take some pictures that show that. Regarding dissasssembly, my father used to say when I was frustrated taking something apart "Well the manny put it together, so you can take it apart". He would not have approved of me breaking off the plastic tabs to open it up!

 

Here are some pictures. I hope they are self explanatory. You'll see that all is clean inside, and there are no cracked gears and no contacts. The motor turns freely in both directions when 9V applied, though I haven't re-assembled the unit to see if it drives the locking pin/rod. It can only take a couple of turns to move the locking pin so I wonder if that is done by a very brief electrical connection to the motor. There is nothing obviously broken. So the actual cause of it not working remains unknown.

 

Here are a number of thoughts and observations.
This charge door locking actuator may not be specific to our Konas. It is somethiing that could be applied to fuel filler caps, glove box doors and the like on other vehicles. Although the paper label on my defective actuator is unreadable there are numbers moulded into the plastic - KF2 ETABZ1. So it is possible that there is a body of knowledge about what causes them to break down if that are very many in the wild.

As to the plunger of the actuator, it moves freely. There is neither debris nor scratches. Initially it takes about 600 grams to move it in, rising to about 900 g as the spring compresses, and then to 1200 g to make it "click" and stay in the closed position. As the plunger is pressed in it spirals 90 degrees anticlockwise, so that the lugs on the "daylight side" of the plunger can engage with the catch on the inside of the charge door. When in the clicked closed position a cavity in the barrel is available for the locking pin to enter. It is a loose fit. However when in the cavity the pin gets in the way of the plunger when it is pushed in to "unclick" it.

For the unlocking itself then, the motor needs some electricity to turn the worm to rotate the toothed quadrant to move the pin back out. With everything else seemingly in order, what is unknown is why the motor does not start to turn on occasion. A prime suspect is electrical connection inside the motor - do these things have tiny commutators and brushes?

Having said all that, I think I'll now saw the end off the locking pin, or remove the quadrant entirely, and reassemble the actuator. If the new one ever fails, it'll be replaced with the original in its new never lock mode

 

Thanks for the extra detail, John.

Yes, that appears to be a conventional brush commutated DC motor. If you connect an ohmmeter to the motor and rotate the shaft very slowly you can check for any high resistance spots on the armature that would cause it to fail to start, much like what happens with ICE starter motors. That situation is traditionally overcome with a firm blow from a hammer.

 

I was hoping to graph the voltage going to the actuator with an oscilloscope while operating the lock buttons but the connections are all inaccessible between the bumper and the radiator. From what I can see, the IGPM unit (body systems controller) pulses all the lock actuators on one circuit "open loop" and hopes for the best. It's doesn't appear from the wiring that there's any feedback between any individual locks and the controller. When each actuator reaches the end of travel the motor will stall against the load until the completion of the timed pulse, perhaps another 100 ms or so.

A problem that might be occurring with this design is that the motor brushes will land on the same locations of the commutator at each of the lock and unlock positions over the thousands of actuations demanded over a few years. When a voltage pulse is applied in either positive or negative polarity the current spike on the motor before starting and after stalling at the end of motion could cause erosion on the commutator at those spots. Eventually the resistance may be high enough so that the motor occasionally does not respond. I would expect the IGMP drive circuit has some means of current limiting to minimise this damage but it also has to supply enough current to start all the motors in all temperatures and load conditions over the expected lifetime.

That theory would also mean that it's somewhat equally likely that the door could fail to lock as randomly as it fails to unlock. Of course no one is likely to notice if the charge door opens when it shouldn't.

 

That is a good description about what is almost certainly happening. My initial issue that I reported was that I after I got the door to open it did not lock although it stayed latched, whether the car was locked or not, and I was fine with that. The door was not locking but one still had to push it in to unlatch it.

 

SO I thought I'd add to the pain of this issue. It finally happened to me (MY 2020) and my EV Charge was down to 4% (Turtle mode). I fortunately JUST made it back to my garage. Attempted to open Charger door, and nothing. Tried pushing Lock/Unlock like 10 times. Nada. Then tried Bluelink Lock/Unlock. That actually worked - THIS only time.. Several weeks later I had to charge again. THIS time, I couldn't open the door at all using all the techniques I read about here. Called Service Dept and they got me in before I was out of charge. Door was still locked shut when I arrived. They replaced part "81560-K4000 Push Opener" under Warranty. Took them about 2 hours - had to remove bumper.

This is REALLY unnerving and a serious deficit in this vehicle. They SHOULD have provided a Pull cable or something inside the hood to force it open. I could only imagine what the result would be to have this occur on a major trip and being 150 miles from home. Not sure what we can ALL do to get Hyundai to provide a RECALL to insert such a solution ... I had opened a complaint (contact us) via the Owners web site ... their reply was to contact my local service dept.. hmph.

 

You may well know this since you seem to have read this thread a lot so forgive me if I'm repeating: there is a service bulletin that allows for correction of this condition without charge. Those who encounter it should certainly bring it to the attention of their dealer/garage. It's true that a service bulletin isn't a recall but recalls have very specific parameters and the stuck charging door probably isn't going to reach that threshold. And manufacturers do everything they can to avoid recalls.

 

Yes, I understand that part... and I was not charged, as expected. My main point is that there needs to be a solution to be able to open that darn door manually. As I noted, if this was to happen hundreds of miles from home, that would be a serious issue. and Expensive to resolve. (e.g., towing, etc.) Thanks

 

The TSB calls out shimming out the bumper to increase the clearance between the door (attached to the bumper) and the charge port (attached to the car body) to apparently allow more room for the latch pin to push in and turn 90° to the open state. However, I don't think that's the fault we are seeing, which is the failure of the lock motor to withdraw the locking bolt from the pin. As evidence of that, the fix being applied is to replace the actuator rather than apply the TSB.

As with the lengthy "motor rumble" TSB, I think this is another case of an incorrect diagnosis of the root cause. Assuming the diagnosis we've identified here is correct (posts 68 and 71), a workaround would be to disconnect or clip the wires going to the lock motor while in the unlocked position which would disable the locking feature. That means either removing the bumper or identifying which wire needs to be cut at the connector in the photo.

 

I'm sorry, yes this is annoying, but automotive engineering isn't perfect. I owned a Plymouth Turismo that had a undersized clutch cable, lasted about 20K miles, snap, lather rinse repeat 20kmi snap. Yes, it left me on the side of the road, 3rd cable was 3 times fatter. I had an Oldsmobile with a ground wiring harness that ran down the outside edge that would get corroded and keep the fuel pump in the tank from working. Yes, it left me parked in a parking lot 1/2 way down I-95, 6 hours from home and my destination. I could go on and on, with almost every single car I have ever owned. I would rate this problem WAY,way down the list of vehicular issues i have had, pretty much at the bottom. I would not consider it a safety issue at all, if you run your car batteries to zero, that's on you.

IMNSHO a locking door is beyond silly, I think mine is now stuck unlocked and it can stay that way. The purpose of the locking fuel door is to keep people from siphoning fuel. This is kind of a non-starter on an electric, so I would recommend simply disabling the locking mechanism. If someone wants to vandalize your car they are going to pry the whole thing open with a crow bar and break it anyway, and anyone looking for free fuel is out of luck. Latch yes, lock dumb. I mean what's the point?

 

I don't understand either the necessity of a locking charge door. My I6 has it too, and bit of a PITA to always have to unlock the car before I can open the charge door. Never heard of them getting stuck,... yet, but obviously could happen, too.

I don't have it on my Solterra, just a simple mechanical push to open, and then push shut. And then a couple caps to keep moisture out on the ports inside. So don't have to worry about snow or ice ever freezing it shut either.

 

Yea, I somewhat agree. Anti-EV Idiots COULD do something stupid like push gum or something into the charge Port. But that aside, how would you "disable the locking mechanism"? Short of sawing off the latch itself? If there was a dedicated fuse or something, that may be an option for me. Especially temporarily for long trips. (my biggest fear) Side note: Right after getting home from the service shop & them replacing the latch, I tested it at home ... By damn if it wouldn't open ! Doors unlocked. Tried the Lock/Unlock method a bunch of time, nada. I was P-O'd needless to say. Then I tried the Key FOB .. low and behold it opened. I'll have to keep an eye on this. I'm fairly certain they did NOT do the "shimming" part of that TSP mentioned earlier. Just the latch replacement piece.

 

It would be non-trivial, but read the actual problem details above, someone replaced the actual electrical part. Basically the latch itself is not the problem, its the actuator that locks it in place to keep the latch from spinning/turning. Hence, once it's unlocked you can take your finger and push it in and out and it moves freely. You'd have to remove the bumper cover and find the wire that activates the lock mechanism and cut it, and then force/make sure the lock mechanism in the unlocked position. You don't want to take out the latch sensor (door open/closed) for obvious reasons. Without a wiring diagram it would be tough to do something farther back in the harness. It really wouldn't be that difficult, but would take a great deal of time.

I have a replacement charge port coming because I have had some charging issues that appear related. If I end up installing it this will happen to mine.