How often do you have to reboot the display?

[WinterDragoness]

I've gotten touchscreen unresponsive on average once every week or two for the last 3 years. It comes in waves where I get the error almost every time I get in the car for 1-3 days, then it goes away for 2-4 weeks. Power saving mode was on, always connected was off.

After 3 years, my GPS started freezing, so I took the car in to service. They replaced the MCU (which includes touchscreen). After a couple days, replaced touchscreen went black and had to take to service to replace MCU again.

New MCUs all had LTE connection whereas old MCU had only 3G. It was a bit faster overall which was nice. They said it was basically an older MCU that still fit 2014 era cars retrofitted with a newer cell modem and possibly a faster CPU. I also noticed rebooting it took longer and holding scrollwheels seemed to reboot the main screen and the steering wheel screen at the same time. It used to be only the main screen would reboot.

Unfortunately, touchscreen unresponsive problem remained about as frequent. I thought I might just live with it, but at one point I parked the car for 2 hours and it had lost 10 miles of range when I returned to find touchscreen unresponsive. Service said logs showed the touchscreen had frozen in such a way that it had been draining power. 10 miles of drain in 2 hours?! I'm not sure but maybe it froze with AC on. Now I'm paranoid that will happen somewhere where losing so much range will be a disaster requiring towing. I never had a range loss like that before the first MCU replacement.

So I keep bringing the car to service. At one point they saw an error with the steering wheel screen (instrument cluster) so replaced that too.

They have replaced the MCU 3 times now and the problem remains. After the last replacement, it got worse in that it would happen almost every time I got in the car. Finally figured out that could be fixed by turning off power saving mode, but that gets me back to touchscreen unresponsive every 2 weeks or so. I haven't seen it happen multiple days in a row like I used to, so behavior has changed a little. It's currently in service again and they're replacing the MCU again... ARGH.

All through this process they keep seeing USB errors in the log and asking what I've left plugged in. The only thing I ever plug in is my Samsung Galaxy S6 to charge it, and I rarely leave it in the car when I exit the car. I've tried four or more different USB cables in case the cable itself is somehow causing the problem. I've had the touchscreen freeze with no USB cable plugged in at all, but it usually happens with just a cable and no device plugged in. They say the USB controller is part of the MCU and can't be replaced separately.

MCUs that fit my car seem to be becoming rare because this is the second time they've had to wait a week or more for the part. It's conceivable I keep getting 'factory refurbished' parts that each have different problems that weren't really fixed by refurbishing. Or they all have a defect where plugging in certain USB devices will destabilize the MCU so it may freeze even after unplugging the device.

The next thing I'm going to try is using only USB cables where just the two charging pins are connected but the data pins are not. That will prevent the phone from ever being seen as a USB device by the car so it can't possibly trigger any sort of issue.

 

[David99]

That's crazy. They seem to have no idea what the real problem is and since the problem remains the same with different MCUs. I would think the root of the problem is somewhere else but the MCU.
My car is also a 2014. Very few times have I had the lagged responses (more in the first year of ownership, not any more in the recent years) and even more rare did my screen freeze up. Maybe four times in 5 years.

If you think the USB is the problem, use the cigarette light outlet to plug in a phone charger. That's what I use all the time. Not because I have issues with the USB but because charging on these ports is painfully slow.

 

[WinterDragoness]

I got my car back today. Apparently, they found something in the MCU had been burnt out by something I connected to the USB ports. This was at least the second time they found this had happened and the second time they replaced the MCU and all the wiring between it and the USB ports. They actually failed to explain how much they replaced in my last visit in Nov, but looking back at the invoice now, it's a significant list:

USB BUNDLE, ASSEMBLY, IP, MEDIA 1 W/OUT HUB (1004815-07-D)

MCU,MDLSX.NA PREMIUM,REMAN 1 (1098010-00-D)

PHONE DOCK KIT FOR INTEGRATED 1 CENTER CONSOLE - MICROUSB (1060584-00-B)

USB MEDIA HUB PORTS (1004815-01-B) 1

Corrections: USB Media Port - Center Console

Replaced USB hub In center console due to Ingress of foreign object.​

I have no idea what the "foreign object" could be. I'm not dropping crumbs in the USB ports or anything, and one of them is perpetually filled by a USB cable.

It seems like a serious design flaw that plugging anything into USB could damage the MCU and the rep said something about it being more protected in later MCUs, but I was basically talking to the customer service guy about tech issues he didn't truly understand so I can't say for sure. I've only ever plugged in my Samsung Galaxy S6, and recently a new roommate's Galaxy S7. It's hard to believe my S6 has an electrical flaw since I've plugged it into my desktop, laptop, an external battery, etc without issue. It's also hard to believe the Tesla's USB bus is so sensitive that this could happen with a really common phone but nobody else is talking about it happening to them.

Bottom line is I can't safely use the USB ports for anything without risking this problem again, and they warned me another fix may not be covered. Not too happy. If anyone else has more information or theories, please let me know.

One possible theory is that few people use the USB ports to charge phones like I do. Instead they use the faster cigarette lighter to USB adapter David99 mentioned. Unfortunately, my cig lighter is used by my GPS. It's probably somewhat rare for cars (like mine) to not have GPS nav built in. I think they discontinued the option to omit GPS nav in maybe 2015? I think there exist cig lighter adapters that can provide USB power and still allow my GPS to plug in, so I'm going to have to go with something like that.

 

[WinterDragoness]

Another reason I kept bringing the car in for service is that it used to show what superchargers were out of range by showing them as ghosted images (50% transparent). Around the same time my GPS started freezing, all chargers became ghosted no matter how close they were. I assumed the problems were related.

Sometimes the ghosted problem went away after the MCU was replaced and then mysteriously returned some random time later. Sometimes it remained after an MCU replacement. The problem had finally gone away for quite awhile but it returned when I picked the car up from a recent service for bodyshop work (no MCU replacement). Super frustrated, I took the car back a couple months later.

A tech named Chris in Pomona had originally come up with the USB burnout theory, but I got an appointment at Cathedral City because it had earlier availability. I repeatedly tried to get an explanation as to what using the USB ports was really doing and why I continued to have problems when I stopped using ports. I wrote a letter asking the question which was ignored, I also asked when I dropped the car off and they said they'd look into it. When they said the car was ready to pick up I asked again and they acted like I'd never brought up the issue before but after I explained it again they agreed to keep the car and have their senior technician look at it.

The new explanation is that cars without GPS navigation installed would show superchargers in range until sometime in 2018 and then that feature was removed (they didn't phrase it that way - they seem to think I should have never had the feature). When I had the MCU replaced, sometimes I got the feature back but at some point firmware would recognize I didn't have GPS nav and so all chargers would ghost. I don't think the ghosting return corresponded with firmware updates because I had always suspected this explanation so I was actually looking for that. Removing a feature like that is incredibly obnoxious but they said since I'd had the MCU replaced with a newer model, it now had the hardware for GPS nav and they could enable it for $145. So I did that. So far, the ghosted supercharger issue is resolved.

The senior tech also says the touchscreen unresponsive issue is not a hardware issue. It's been reported by other drivers and may be fixed by a firmware update someday. Since I've had the issue for the 3.5 years I've had the car, I'm not holding my breath.

When I finally picked up the car, I asked again about the USB burnout. They couldn't find anything in the car history notes regarding it. All they could suggest was it was a misdiagnosis. They thought I could use the USB ports.

I tried mailing Pomona again and was ignored as usual. I could call them and keep hounding them till they look into it but doing that isn't really in my nature and unless I can reach the original tech that diagnosed it I doubt I'll get an answer. So I doubt using USB ports was ever doing any hardware damage, but I'm still going to keep avoiding them because I have no need of them. Charging devices via a cig lighter adapter is much faster.

Also note that I was repeatedly told that errors in the log showed having my phone plugged in was triggering the touchscreen unresponsive somehow. Covering the USB ports did not reduce touchscreen unresponsive much if at all but it may be another possible source of the error.

 

[WinterDragoness]

At some point after I wrote the above post I realized it hadn't done touchscreen unresponsive for quite awhile. I tried turning on "Energy Saver" mode which has always caused touchscreen unresponsive almost every time I enter the car since my first touchscreen replacement, but this time it was fine. I've left that setting on and have not had a single touchscreen unresponsive since my last post. I guess they finally, finally fixed it with a firmware update. Or adding GPS nav helped somehow. I think I had one or two touchscreen unresponsive after gps nav was enabled but I don't remember for sure.