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"Unable to Charge" Errors Appearing Mysteriously. Is Software to Blame?

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Has anyone seen a change with firmware 24.4? My X got the update the other day and it seems to have solved the problem. I haven't tested it thoroughly but I know for sure one charger that was giving it trouble before is fine now. That same charger still gives problems to my S, which is still on version 20.4.2.
 
I just saw this problem for the first time on Sunday while trying to supercharge. I supercharged on Saturday just fine. My software was updated to 2019.24.4 the Thursday before. This is on a 2015 Model S 90D. The technician said something about the supercharger handshake not working and that regular charging should still work (it did). I made an appointment (2 weeks from now) to have them check this out.
 
Hi Tesla Mortor Club Forum,

I have experienced a similar issue, that I'd like you help on:

My Tesla Model S 2014 has been working just fine for the last couple of years with absolutely no charging issues. I have been charging with 15/15A with no problems for years at home - and also from time to time on the road on other chargers.

I have sold the car to a new owner mid July, as I want a new Tesla - the new owner is now experiencing similar challenges to this post and have turned to me for help, as this is his first Tesla.
On the day I did hand over, I did a reset from the main screen to wipe all personal information and also give the new owner a great experience and set it up with him. It was on SW Version: 2019.20.4.2. when he took over the car.

He now reports back to me after a week of take over, that from time to time, he experiences "unable to charge" error message. The charger automatically lower to 10A, the charging continues with no issues. (see picture)

When he changes at home (at 13/13A) he experiences no problems what so ever.

When he spoke to Tesla services initially, they immediately suggested that the charging-unit was defect and needed replacing - since the car is out of the first warranty we don't want to jump to expensive conclusions ;(

Any good advice on what we should try out? (Or how we can validate root cause?)

Thanks in advance!

/Peter

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So... I have an update after getting it back the first time (where they changed the charge port) and I continued to get the error Tesla changed the charger on my X after denying me the first time telling me the vehicle was "operating as designed". They claimed my electric service was spiking at 280 volts causing the car to "trip out" and bump down to 47 amps to protect itself. I went back home took apart my main panel and connected a fluke meter to the breaker along with an amp clamp. I was able to monitor the charge (sample 25 times per second) and determine when the car was dropping to 47amp charging. No spikes occurred during the charge and yet after several minutes the car would drop to 47amps and put that message on the screen. I'm not sure if its tied to a bad software update or some kind of a firmware for the charger but they decided to change the charger on the vehicle. I'm supposed to get it back today with the work completed so I'll test it and report back but it was an uphill battle. DC charging was not effected because that doesn't use the vehicle charger.

Most likely the charger on your car needs to be replaced I asked what this would've cost out of pocket to have it done on my X and they told me $2600.00
 

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So... I have an update after getting it back the first time (where they changed the charge port) and I continued to get the error Tesla changed the charger on my X after denying me the first time telling me the vehicle was "operating as designed". They claimed my electric service was spiking at 280 volts causing the car to "trip out" and bump down to 47 amps to protect itself. I went back home took apart my main panel and connected a fluke meter to the breaker along with an amp clamp. I was able to monitor the charge (sample 25 times per second) and determine when the car was dropping to 47amp charging. No spikes occurred during the charge and yet after several minutes the car would drop to 47amps and put that message on the screen. I'm not sure if its tied to a bad software update or some kind of a firmware for the charger but they decided to change the charger on the vehicle. I'm supposed to get it back today with the work completed so I'll test it and report back but it was an uphill battle. DC charging was not effected because that doesn't use the vehicle charger.

Most likely the charger on your car needs to be replaced I asked what this would've cost out of pocket to have it done on my X and they told me $2600.00
Any update on that resolving your issue?

I got the 28.3.1 update a week or so ago (2017 X) and experienced weirdness w/various systems. The alert about blindspot camera woes, then a supercharger visit resulted in the charge rate being severely lower than normal supercharger rate. Usually I'd get 300ish miles/hour but this time it was 150ish, down to 0, up to 90, down to 0, up to 150ish....just 'bouncing' like it kept resetting. But no warnings/alerts and it did charge. From 90mile range to full (max trip range) took 1h50min which is well over 2x 'usual' rate.

First time charging at home after that, I start getting the Unable to charge/Disconnect cable and retry warning. I've done the cleaning, remove/reinsert, power cycle the charger (JuiceBox 80A, capped at 40A on a 50A breaker). Wiring is all perfect and swell. Voltage is 244-246V. Charging actually occurs, but @ 20/40A. Been using same charger w/out issue w/a Leaf, Bolt, and the X since late 2017.

Seriously frustrated!
 
My problem finally appears to be a bad charger and not voltage. A car power off and restart clears the charger in the car and it’s fine again. The voltage is never over 249 and that should be within specs.

My electrician, which is a Tesla certified one, escalated this to the Home Charging group at Palo Alto (HQ) and they now have a ticket for the Service Center to look deeper into it.

The symptom is now (and really was, voltage was the wrong theory) that the charger board is not seeing external power, which is why it says ‘check power’ and has a red port on the app (only) (not on the car).

The board seems to have been rebooted/reset by some process in the car. This last time that didn’t happen after days so I turned off the car from the menu (which I thought I had done but nope). That cleared the charger main board and all is well. Until next time. Best case would be that the board hangs again in time for an annual maintenance appt I have next week.
 
So... I have an update after getting it back the first time (where they changed the charge port) and I continued to get the error Tesla changed the charger on my X after denying me the first time telling me the vehicle was "operating as designed". They claimed my electric service was spiking at 280 volts causing the car to "trip out" and bump down to 47 amps to protect itself. I went back home took apart my main panel and connected a fluke meter to the breaker along with an amp clamp. I was able to monitor the charge (sample 25 times per second) and determine when the car was dropping to 47amp charging. No spikes occurred during the charge and yet after several minutes the car would drop to 47amps and put that message on the screen. I'm not sure if its tied to a bad software update or some kind of a firmware for the charger but they decided to change the charger on the vehicle. I'm supposed to get it back today with the work completed so I'll test it and report back but it was an uphill battle. DC charging was not effected because that doesn't use the vehicle charger.

Most likely the charger on your car needs to be replaced I asked what this would've cost out of pocket to have it done on my X and they told me $2600.00

any updates? Working now?
 
My problem finally appears to be a bad charger and not voltage. A car power off and restart clears the charger in the car and it’s fine again. The voltage is never over 249 and that should be within specs.

My electrician, which is a Tesla certified one, escalated this to the Home Charging group at Palo Alto (HQ) and they now have a ticket for the Service Center to look deeper into it.

The symptom is now (and really was, voltage was the wrong theory) that the charger board is not seeing external power, which is why it says ‘check power’ and has a red port on the app (only) (not on the car).

The board seems to have been rebooted/reset by some process in the car. This last time that didn’t happen after days so I turned off the car from the menu (which I thought I had done but nope). That cleared the charger main board and all is well. Until next time. Best case would be that the board hangs again in time for an annual maintenance appt I have next week.
So, the final story is a little different. It’s not overvoltage and a reboot does reset it, so it’s more an annoyance than anything.

Tesla and I can’t ever reproduce this when it’s at the SC or when I can, by the time I get in the car and drive it, it’s fine again.

It also fixes itself if I reboot the car (normal two scroll wheel reboot). Something hangs the charger controller board and needs a reboot to clear it and Tesla won’t replace it without seeing it themselves, of course.
 
To add to this: something in the car is affected by heat two ways, lol. And it’s not the charger. (And reboots or power down don’t fix it now!)

1. Had this happen as usual in hot temps in the summer in the garage a month ago. After a week of the car not recovering, drove to the mall and back (nice 20 miles round trip) and it fixes it. Okay, perhaps some charger component has a solder joint that bakes open and a trip heats it up and does who knows what. That was the theory for the last two years as it always self-healed or worked after a trip (or being driven to the SC in Tyson’s, grr). But wait.

2. Today, it’s been not charging at home for ten days. Decided to do two things. First, we have a shiny new supercharger literally a mile away (woohoo!) so, that will rule out some stuff. I was shocked (not literally) when it didn’t charge there either. (Tried stalls 1A and 1C at Chantilly, one of which I saw a 3 leave a second before.)

So: it’s NOT the onboard charger. What else is in common that would be sensing power level/flow? The charge port?

When we got home, of course the trip had warmed up something to the point it charged with the WC again.

I made an appointment anyway saying this is unacceptable now that we know both WC and Supercharger charging are disabled randomly until you drive x number of miles to heat something up.

Anyone seen anything like this or have an idea?

Got a mobile service (the default of course) scheduled for Wednesday and hope that they leave it mobile.
 
Newest update here is they can't do anything without me bringing the car to Tyson's which means, it may be weeks or months until it exhibits the same behavior again. (Or months, since we getting past the hottest part of the year....).

So, I told the virtual service guy what I'd do is next time it did it, I'd make another appointment and we'd have mobile come out and try to see what was up and then take it in when they got whatever parts they thought was needed. Since mobile can't (they said) replace the parts needed). It could be as easy as the cabling in the charge port (seems pretty simple, but I do doubt that, that that would get heated up and 'reconnect' by a drive and also disconnected by heat in the summer).

So, on we go.
 
One more occurrence, and this time the trip to the supercharger a mile away was enough to 'fix' it. Arggg. So, now, I'll wait until the next time and not even test with a supercharger, as we know it doesn't work on a supercharger and they already have that info. I'm about to give up, since if it fixes itself with two miles of driving, WTF. Fix it that way, or wait until it croaks (whatever is wrong with it) completely. This is insane. What part is affected by heat (only happens in the summer) but is corrected by heat (driving...). I can't see how vibration (loose wires) could be it as all sorts of moving the charger plugs don't make a different, but perhaps. In the past, recall, it fixed itself just sitting in the garage after a few days, but that no longer happens.
 
Finally updating with what I thought would be the answer and sigh it’s not. Tesla finally agreed to come out two weeks ago and have mobile replace the pilot ‘trident’ cable from the charge port to the charger. Makes sense if this cable was flaky as the pilot pins (the two low(er) voltage ones in the charge port (and lower physically) are the ones that control whether the car knows that a valid charge wand is present.

That was replaced, took about exactly an hour by mobile, car worked perfected for 13 days and once again ‘check power’. Made another mobile appointment this morning and they will be here Thursday. I’m thinking the only other component it can be is some sort of charging circuit control board.

This previous time I waited two weeks to be sure the car wouldn’t ‘self repair’ the way it had so many times and the interval of having the issue is getting more frequent and time it takes to fix itself is getting longer so whatever it really is Is definitely deteriorating.