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Charging reduced - Overheat detected at wall connector error TM3 SR+

Fady

Member
Jul 30, 2020
7
13
Bedford
Following a firmware update to 2020.24.6.9, I started to get an error message "Charging reduced - over heat detected at the wall connector".

After plugging the car into the charger, it charges fine at 32A for 2-3mins then this message pops over, and the charging gets reduced to 16A (15mi/hr). No other error messages apart from this. Normal green T on the car, normal "flowing" green on the wall connector.

Phoning up the service team, their remote diagnosis team concluded that the issue is related to the charger installation, and I should get in touch with the electrician, which I did and then the blaming game started between Tesla and the company which fitted the charger. Tesla has now pulled my car log and are investigating further ! Issue not resolved, and I still get this msg 2-3mins max after plugging the car in.

I started investigating myself, first by having a closer look at the charger itself. It is fitted outside in the shade, the unit is not hot (even after removing the face..yes I had my brave pill and did that!) nor is the connector.

I then went earlier today to a destination charger (a country hotel/pub) which has few Tesla wall chargers available free of use to see if I get the same error. It seems everything is working fine, HOWEVER, this particular charger seems to be installed on 3 phase power, so it is already working on 16A even though it's juicing 45mi/hr..so not really comparable to mine at home, which doesn't trigger this error when I use it on 16A (although mine only gives 15mi/hr as it's installed on a single phase)

Oddly enough, the hotel owner came out, very pleasant lady, saying that there was earlier another guy who was also testing his car for the exact same issue! she says there is hardly anyone using these chargers due to the lockdown and due to the fact that the hotel is still closed for business

To me it's too much of a coincidence that this error only happened the following day of a firmware update + plus the hotel owner's story!

I'm wondering if anybody out here faced this same issue?
 
  • Informative
Reactions: NOLADriver

Fady

Member
Jul 30, 2020
7
13
Bedford
Thanks, Ravire - Yes I've come across this fault, but it seems related to Gen3 wall chargers, which is a smart charger with its own firmware. Sorry I should have mentioned I'm using a Gen2 wall charger as it's the only available model in the UK
 

Ravire

Member
Feb 13, 2020
187
130
Orange County
Thanks, Ravire - Yes I've come across this fault, but it seems related to Gen3 wall chargers, which is a smart charger with its own firmware. Sorry I should have mentioned I'm using a Gen2 wall charger as it's the only available model in the UK
Oh didn’t know you had gen 2 well other than cycling the breaker I’d push Tesla to replace it
 

Fady

Member
Jul 30, 2020
7
13
Bedford
Oh didn’t know you had gen 2 well other than cycling the breaker I’d push Tesla to replace it
Thanks - I'll wait for their diagnosis to conclude and probably that's what I'll do eventually - They already have me booked for service in two weeks - but I don't think it's a car issue to begin with so I'm not sure how driving 100miles to get my car tested would help!
 

Fady

Member
Jul 30, 2020
7
13
Bedford
Ok - a new update from Tesla - Apparently it's a software issue with the current firmware 2020.24.6.9. I've been told that this should resolve itself with the 24.8 version. No estimated time as to when this becomes available

I thought I'd update the post here - in case you come across the same issue, you now know what to do (Do nothing, wait for the new update, meanwhile try to enjoy the slow charging with Netflix or something!)

I'll confirm once/whether the new update solves the issue
 

Fady

Member
Jul 30, 2020
7
13
Bedford
Ok - I’ve been told that at lot of model 3 owners are now experiencing this and it’s an old bug that crept back to the current firmware in the uk - it should get fixed on the 2020.28 version once it comes out.
 

twentw

Member
Apr 18, 2019
23
19
Houston
Ok - I’ve been told that at lot of model 3 owners are now experiencing this and it’s an old bug that crept back to the current firmware in the uk - it should get fixed on the 2020.28 version once it comes out.
Anyone still having this problem? I’m running 28.6, and it’s still stepping down to 16 amps.
 

Fady

Member
Jul 30, 2020
7
13
Bedford
Anyone still having this problem? I’m running 28.6, and it’s still stepping down to 16 amps.

Mine was fixed with the update - however, I happened to have an electrician booked on the same day I installed the update to fit an earth rod that the previous electrician didn't both installing (according to the wall charger user manual and the UK regulations, it's a must). I explained him the overheating issue and had him looking at the electricity wires going inside the charger as well. He said that the connections were not tight enough and there was charring/blackening around the screws despite having the unit fitted for less than 2 weeks (indicating that the initial guy did a horrible job!). So he cleaned and tighten these up, and didn't have a problem since.

Since both the update and the electrician checking the connection happened on the same day, I can't really tell which one actually fixed the problem..but it looked like a compound issue..the software bug making the charger oversensitive to heat (therefore not a bug, but a good thing!) Plus issues with the actual installation triggering it..so you might have the same?

If you are confident enough, you can check the internal connection yourself. It's not a difficult job (takes 5 mins) but obviously make sure your charger unit power is off, no power whatsoever is going into the unit and you do so with maximum care and during day light
 
  • Informative
Reactions: Phlier

Roadrash

Member
Jun 7, 2020
26
36
California
I got a new charger installed when I got my car 6 weeks ago, worked perfect until that last software update to the charger, now my speed was cut down from 41mph to 21 mph, I tried reducing the amps to 32amps and it cuts it in half to 16amps. What ever my speed is, it starts at at 41mph then drops in half no matter the setting. Tesla said they thought it was the charger a week or two ago when I called, said they would warranty it cause it is not a software issue. Although the electrian is seeing more of this happening, I think it is all software. They were supposed to send me a new charger but they are sold out. I wonder if a update will go out soon that will fix it. its really annoying, especially as a new owner wondering what was wrong with my expensive charger or vehicle
 

Fady

Member
Jul 30, 2020
7
13
Bedford
I got a new charger installed when I got my car 6 weeks ago, worked perfect until that last software update to the charger, now my speed was cut down from 41mph to 21 mph, I tried reducing the amps to 32amps and it cuts it in half to 16amps. What ever my speed is, it starts at at 41mph then drops in half no matter the setting. Tesla said they thought it was the charger a week or two ago when I called, said they would warranty it cause it is not a software issue. Although the electrian is seeing more of this happening, I think it is all software. They were supposed to send me a new charger but they are sold out. I wonder if a update will go out soon that will fix it. its really annoying, especially as a new owner wondering what was wrong with my expensive charger or vehicle

Tell me about it!!

Oh..I also forgot to mention. When I installed the new update, first thing I did was obviously plugging the charger in, 2mins later and I got the same error msg of charging speed reduced. I then did a hard restart on the charge (press the red reset button on the unit for ~5sec until you get a light blink and it becomes a solid green - Took my car for a long drive, came back and it was working fine.

Why don't you try the same steps and let me know:
1. disconnect the charger
2. do a hard reset for 5-7 secs
2. check on the car screen that the charging is set to the maximum (32A) - very important as the car itself drops the maximum power as soon as it reads this error msg, and it keeps it dropped every time you connect to that same wall unit
3. Make sure that the charger power dial is set to deliver 32A - Can't recall which number it is on the red dial, I think it's 8 but do check the user manual
4. Take your car for a drive
5. plug it in and check how it goes

I hope this helps

P.S. Also don't exclude the possibility that it's a compound problem, software + the charger connectors are not properly installed by the electrician and in this case it will trigger the issue now that with the new update the temperature sensor is more sensitive to heat.
 
  • Helpful
Reactions: Phlier

Gasaraki

Active Member
Oct 21, 2019
2,079
1,439
Syracuse, NY
Following a firmware update to 2020.24.6.9, I started to get an error message "Charging reduced - over heat detected at the wall connector".

After plugging the car into the charger, it charges fine at 32A for 2-3mins then this message pops over, and the charging gets reduced to 16A (15mi/hr). No other error messages apart from this. Normal green T on the car, normal "flowing" green on the wall connector.

Phoning up the service team, their remote diagnosis team concluded that the issue is related to the charger installation, and I should get in touch with the electrician, which I did and then the blaming game started between Tesla and the company which fitted the charger. Tesla has now pulled my car log and are investigating further ! Issue not resolved, and I still get this msg 2-3mins max after plugging the car in.

I started investigating myself, first by having a closer look at the charger itself. It is fitted outside in the shade, the unit is not hot (even after removing the face..yes I had my brave pill and did that!) nor is the connector.

I then went earlier today to a destination charger (a country hotel/pub) which has few Tesla wall chargers available free of use to see if I get the same error. It seems everything is working fine, HOWEVER, this particular charger seems to be installed on 3 phase power, so it is already working on 16A even though it's juicing 45mi/hr..so not really comparable to mine at home, which doesn't trigger this error when I use it on 16A (although mine only gives 15mi/hr as it's installed on a single phase)

Oddly enough, the hotel owner came out, very pleasant lady, saying that there was earlier another guy who was also testing his car for the exact same issue! she says there is hardly anyone using these chargers due to the lockdown and due to the fact that the hotel is still closed for business

To me it's too much of a coincidence that this error only happened the following day of a firmware update + plus the hotel owner's story!

I'm wondering if anybody out here faced this same issue?

I've been having charging slowing down after like 30 mins to 24A from 48A the last few weeks. Called wall charger support and they said that their firmware is slowing down people's charging because it's "overheating". I'm about to call again, I didn't pay $1000+ to get charging slower than the mobile charger that came with the car.
 

twentw

Member
Apr 18, 2019
23
19
Houston
If you are confident enough, you can check the internal connection yourself. It's not a difficult job (takes 5 mins) but obviously make sure your charger unit power is off, no power whatsoever is going into the unit and you do so with maximum care and during day light

I took mine apart and it looked pristine even after 16 months. I was able to tighten up the connections slightly. I’m wondering what would the temperature need to be for it to legitimately overheat? This time of year my garage can easily be 120F. Is that hot enough to cause a problem?
 

Gasaraki

Active Member
Oct 21, 2019
2,079
1,439
Syracuse, NY
I took mine apart and it looked pristine even after 16 months. I was able to tighten up the connections slightly. I’m wondering what would the temperature need to be for it to legitimately overheat? This time of year my garage can easily be 120F. Is that hot enough to cause a problem?

My garage is maybe 80F and even on days that were in the 70s, it still "overheated". What a pain in the ass.
 

Phlier

Bluebird
Jun 12, 2019
1,869
3,207
Utah
I took mine apart and it looked pristine even after 16 months. I was able to tighten up the connections slightly. I’m wondering what would the temperature need to be for it to legitimately overheat? This time of year my garage can easily be 120F. Is that hot enough to cause a problem?
I live in the hot, hot desert. We hit 100F the first of June, and don't see a day below 100 until mid September. I have never had an issue with my Tesla Wall Connector slowing down at all from overheating. We've been between 108 and 113 the last two weeks. If you're curious, check out the climate for Saint George, Utah. ;) We stay within five degrees of Las Vegas, Nevada throughout the year.

In addition to the fact that it's just dang hot here, my garage sees additional heat from two 50 gallon natural gas fired water heaters. These put out enough heat to keep my garage at 60F when it's well below freezing outside. So yes, my garage is hot, hot, hot. Even a heat conditioned desert rat like myself can't stand to be in my garage for more than five minutes this time of year.

And not one heat related charging issue.
 

lolder

Member
Jun 11, 2016
916
825
SW Florida
I recently found 2 notices that charging speed had been reduced due to high connector temperatures with the UMC 2 plugged into a 14-50. Nothing changed. I think it's a software bug with the recent update.
 

SageBrush

REJECT Fascism
May 7, 2015
12,550
16,580
New Mexico
I recently found 2 notices that charging speed had been reduced due to high connector temperatures with the UMC 2 plugged into a 14-50. Nothing changed. I think it's a software bug with the recent update.
I'm confused -- I thought this problem concerned the Gen3 wall connector EVSE
 

lolder

Member
Jun 11, 2016
916
825
SW Florida
With software bugs it's hard to predict what items are affected in the charging system. I do know that the 14-50 outlets where a screw mashes the #6 wire are inferior to the Hubbell type where V jaws grip the wires. The screws always have to be as tight as you can get them.
 

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