Getting "Charge Rate Reduced- Wall Plug Temperature High"

[SeanM]

Have been getting this error message from past one month now. I own a 2018 Model-3 model and didn't get this error in any season to rule out hot temperatures in the garage, hence am a bit worried about it. Due to that the overall charging has gone down to 13miles per hour from 28 miles per hour.

I checked the wiring in the wall & receptacle on the wall, nothing seems to be wrong. Only thing is the mobile connector that we get with car, the box (See circled in third attached photo) black box thing attached to mobile connector is warmer to touch, but as its always connected to the wall hence it's usually warm to touch, but get a tad bit more warmer when charging.

BOTTOM LINE.... never had this issue past three years till now... any idea what do I need to do?

Btw, is that mobile connector covered under the four years warranty by Tesla??

I apologize if am not able to explain correctly, thanks in advance for your suggestions & time, much appreciated!!

 

[Frank99]

The error message says “wall plug”, so I wouldn’t worry about the body of the Mobile Connector. There’s two possibilities I can think of here:
1. The temperature measurement circuit in the adapter has failed, making the MC think the wall plug is hot. For this you’ll either need a new plug adapter, or a new Mobile Connector.
2. The wall plug really is hot, which indicates something in the outlet has broken or the wires have come loose. The MC reduces charging current so that, you know, your house doesn’t burn down.

Test: start charging at full rate while sitting in the car; when the error message comes up on the screen, jump out, unplug the MC and feel the outlet. Warm is ok, “Ouch!” Is bad. If the outlet is hot, I suggest replacing the outlet. If it isn’t, it’s probably a problem with your MC.

 

[Yukki]

I'm running into the same issue. I've noticed from my research that a lot of people are reporting this and it started around a month ago. I looked at my tesla fi logs and noticed that I started to get this error and charge rate reduction on 9/13. So I checked if I got a software update on that date and sure enough I did. I installed update 2021.24.11. Just figured I would drop this info to see if it helps identify if its the software being weird. I just find it weird that it started as the Texas temps are going down and I never got anything during the 100-110 degree summer weather.

 

[quikshifter]

I had this error few times recently Adjusted the wires a bit on the mobile charger and it went away

 

[SeanM]

I had this error few times recently Adjusted the wires a bit on the mobile charger and it went away

What do you mean by adjusted the wires?? How did you do that??

 

[SeanM]

The error message says “wall plug”, so I wouldn’t worry about the body of the Mobile Connector. There’s two possibilities I can think of here:
1. The temperature measurement circuit in the adapter has failed, making the MC think the wall plug is hot. For this you’ll either need a new plug adapter, or a new Mobile Connector.
2. The wall plug really is hot, which indicates something in the outlet has broken or the wires have come loose. The MC reduces charging current so that, you know, your house doesn’t burn down.

Test: start charging at full rate while sitting in the car; when the error message comes up on the screen, jump out, unplug the MC and feel the outlet. Warm is ok, “Ouch!” Is bad. If the outlet is hot, I suggest replacing the outlet. If it isn’t, it’s probably a problem with your MC.

I did remove the MC plug from the wall and felt the pins, they were cool to touch not even warm. So, I knew that it's not the outlet unit on the wall. Is the MC covered under the car's four year warranty? If so, then I can get it replaced, else it's for $500. :-(

 

[SeanM]

I'm running into the same issue. I've noticed from my research that a lot of people are reporting this and it started around a month ago. I looked at my tesla fi logs and noticed that I started to get this error and charge rate reduction on 9/13. So I checked if I got a software update on that date and sure enough I did. I installed update 2021.24.11. Just figured I would drop this info to see if it helps identify if its the software being weird. I just find it weird that it started as the Texas temps are going down and I never got anything during the 100-110 degree summer weather.

Yes, so did mine too. I started seeing this issue since past one month. I usually keep the car plugged in at night hence didn't see any difference. But drove a lot yesterday and had to get the car recharged over 150 miles last night, that's when I saw this error, it was same a few weeks back too.

 

[brkaus]

What do you mean by adjusted the wires?? How did you do that??

Schedule an appointment using the app for the earliest date possible and include all the details and the warranty question in the details.

 

[SeanM]

Schedule an appointment using the app for the earliest date possible and include all the details and the warranty question in the details.

Sounds like a good idea... did anyone get a positive feedback from them. The last thing I want them is to shrug it off as they do for such tickets.

 

[brkaus]

Sounds like a good idea... did anyone get a positive feedback from them. The last thing I want them is to shrug it off as they do for such tickets.

It will likely depend on who answers. It’s the best way to get into the queue.

If you have a friend with a similar setup you can trade parts and do some testing.

 

[Foxtrotter]

I have been getting the same error message and reduced charging on a 3 year old mobile connector that is used several times a week. Started happening a month or so ago. I have a second unused mobile connector and 14-50 adapter from our second model 3. Although the message indicates a problem with the outlet, the other mobile connector works just fine. I also tried exchanging the adapters to see if that was the problem. The adapter from the "bad" MC worked without problem on the new MC and the new adapter didn't fix the problem on the old MC.

Seems pretty clear that the MC has failed. Next stop Tesla service.

 

[SeanM]

I have been getting the same error message and reduced charging on a 3 year old mobile connector that is used several times a week. Started happening a month or so ago. I have a second unused mobile connector and 14-50 adapter from our second model 3. Although the message indicates a problem with the outlet, the other mobile connector works just fine. I also tried exchanging the adapters to see if that was the problem. The adapter from the "bad" MC worked without problem on the new MC and the new adapter didn't fix the problem on the old MC.

Seems pretty clear that the MC has failed. Next stop Tesla service.

So, it started happening for you since past month too? Does it mean, there's some issue going on with the software upgrade that's making these 'mc's go bad or flag as bad??

 

[Flybyglass]

Contact Tesla. I had this issue with a Gen 3 wall connector turns out they had a batch with bad temperature sensors. The interim solution was to reduce the charge rate to 32 amps from 48 amps inside the car to keep the temperature down until the replacement arrived. It is normal for the charge rate to be reduced if the charger detects an overheat but not as you describe. Tech Support for charging is helpful place to start.

 

[Fictional_Yeti]

More than likely it is the UMC that fails after a while... Tesla replaced mine with a mobile appt. including the 14-50. Damn cabling is so thin...

 

[SeanM]

More than likely it is the UMC that fails after a while... Tesla replaced mine with a mobile appt. including the 14-50. Damn cabling is so thin...

I have opened a Service ticket, let's see what they say, will keep you all updated, thanks.

 

[SeanM]

I borrowed my friend's MC and it's not throwing the error while charging, but when I switch it back to mine, it gives the same error. So, I presume that it might be my MC that may have issues. Have opened a Service ticket with Tesla's dealer near me. Will keep you all updated, thanks a lot for your suggestions and advice.

 

[pkwu06]

I borrowed my friend's MC and it's not throwing the error while charging, but when I switch it back to mine, it gives the same error. So, I presume that it might be my MC that may have issues. Have opened a Service ticket with Tesla's dealer near me. Will keep you all updated, thanks a lot for your suggestions and advice.

Please post your result when you have it. I have noticed the same issue in the last few weeks with my 2018 Tesla 3. It looks like that it started to happen pretty much around the same time to us here. I think it's a MC failure due to a software update.

 

[Aikidoka]

Contact Tesla. I had this issue with a Gen 3 wall connector turns out they had a batch with bad temperature sensors. The interim solution was to reduce the charge rate to 32 amps from 48 amps inside the car to keep the temperature down until the replacement arrived. It is normal for the charge rate to be reduced if the charger detects an overheat but not as you describe. Tech Support for charging is helpful place to start.

I had the same problem with my Gen 3 wall connector after about 8 months use. Tesla did some over-the-air testing and then had me use my notebook to upgrade the software. I still had the problem so they sent me a new wall connector. The new ones been working fine for a few months.

 

[jasono]

I started having this issue 2 days ago (9/28). It does sound odd that this issue is impacting many people within a matter of weeks, all of a sudden. The theory about software update being the culprit sounds most convincing to me at this point.

 

[jasono]

Since the temperature sensor is on the mobile connector which is connected to the outlet through a NEMA adapter, it's hard to imagine the outlet being too hot, because it would mean the heat transferred through the adapter is still high enough to trigger the warning, yet it didn't burn the adapter first.