[Atlant]

My car joined this club Friday(ish).

The “Triangle Sensor” switch on the driver's side door on my 2021 AWD Pro S has always been touchy but it has now packed it in completely. I'm pretty sure it's not my finger being too bloodless in the cold because 1) the exact same finger making the exact same gesture on the passenger-side door works fine and 2) other fingers and other sorts of touches/swipes don't work on the driver's side door either.

 

[Atlant]

My car joined this club Friday(ish).

The “Triangle Sensor” switch on the driver's side door on my 2021 AWD Pro S has always been touchy but it has now packed it in completely. I'm pretty sure it's not my finger being too bloodless in the cold because 1) the exact same finger making the exact same gesture on the passenger-side door works fine and 2) other fingers and other sorts of touches/swipes don't work on the driver's side door either.

And yesterday afternoon (not morning, afternoon), the sensor started working again and has worked reliably the several times I've used it since then.

So: Flakey hardware? Flakey software? And will it hard-fail again the day after the warranty expires? I think I'll still mention it to the dealer if only so it becomes a note in the record.

 

[Atlant]

This will be a pain to prove to dealer. I hope it just stops working entirely.

My thoughts exactly!

This may be a superstition on my part but I think I've found that “swiping” across the sensor seems to work better than “touching” the sensor.

 

[Atlant]

When I have washed the car (with a wax finish), if it is covered in heavy rain drops or ice, mine do not work too well either - but a back-hand or wiping them clean first, usually works.

I guess the sensors are somewhat weak, a bit like the sensor in the back for the hatch.

I rubbed the area clean (of road salt, mostly) before concluding that it wasn't working.

 

[Atlant]

And yesterday afternoon (not morning, afternoon), the sensor started working again and has worked reliably the several times I've used it since then.

So: Flakey hardware? Flakey software? And will it hard-fail again the day after the warranty expires? I think I'll still mention it to the dealer if only so it becomes a note in the record.

Dead again this morning. Of note was the fact that the door handle was slightly damp from the dew so maybe the capacitive touch sensor fails when there's conductive dew on the handle? I tried to wipe it dry with my fingers but it remained broken. Maybe I'll carry a tissue and try more aggressive wiping but I think that this sensor is marginal at best and the dealer needs to dew, err, do something about it.

 

[Atlant]

It's rather unpredictable: sometimes, it works no matter the conditions; other times, not at all.

I'm starting to suspect it may have to do with the (lack) of recognition of the key fob, as the auto-unlock is equally dodgy at times.

That's an interesting thought; I'll experiment with that.

I ASSUME that if I take the fob out of my pocket and the LED on the fob is blinking that the car and the fob are successfully in communication?

 

[Atlant]

This morning, my wife and I had to travel together. The ID.4 was kind enough to have the driver's side door triangle broken again so at least I now have a witness to the failure. She and I each tried both sides and the passenger's side operated reliably for both of us and the driver's side never operated for either of us.

I forgot to look at the LED on the fob but the driver's side door has never failed to unlock at the “first touch” of the unlock pad under the door handle so it's probably not the fob radio causing the trouble. (I'll still try to remember to conduct that exact experiment later today.)

The problem definitely ISN'T dew on the handle; I wiped it dry carefully and it still didn't work.

 

[Atlant]

Unfortunately I could be waiting for weeks if not months because door handle part is on backorder.

That's usually the sign of an endemic problem (as we seem to be reporting here). :-(

 

[Atlant]

Spoke to my local service centre last week: They say it is not a common issue, but that they have replaced "a couple"; and the mugwump even started mentioning a sensor below the car (Emphasis added by Atlant) - I am not sure how that would affect the triangle lock sensor, but they will look into the whole thing at the first service.

My GUESS is that was a reference to the fob radio receiver.

 

[Atlant]

Have the same issue appear this past fall. Drivers side only. Passenger side always works. (which is my work around)
Problem is intermittent. Notice this occurs after a really humid rainy day OR when it gets cold & the air is high humidity. Does not matter if the car is dirty of just car washed (also when it happens). Notice the common comment: moisture? Just a guess on my part.

My gut agrees with you that it's moisture related but I haven't been able to say that with certainty, in part because of late here in New Hampshire, nearly EVERY day is a moist day yet the unlock triangle works some of the time, even when the door handle seems to be wet.

guess that … it is a mechanical design flaw

I'd like to know where the capacitive touch sensor IC for each of the door handles is located. For example, on the driver's side, is it a much longer wire run to the IC than on the passenger's side, thereby decreasing the signal-to-noise ratio available to the sensing IC (so that the driver's side handle is much more prone to intermittent failures)?

 

[Atlant]

I've opened a case with VW Customer Care regarding the door handle lock triangle. I figured that this will have several benefits:

1. It assures that VW Corporate actually has me on record as the owner of my ID.4 (seeing as how I've never received any E-mail from them on any topic),
   
   
2. It gets written down on record that I have this problem as of today's date, and
   
   
3. Heck, it might even cause something good to happen regarding this problem.

They promised me a confirming E-mail with a Case ID but so far, it hasn't shown up.