Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

32A max charge rate of LR Model 3

This site may earn commission on affiliate links.
My 2018 LR RWD Model 3 is unable to charge faster than 32A using my Tesla Wall Connector instead of the 48A that it normally does.

I tried unplugging and retrying the charging as the error message suggested and I also tried resetting my Wall Connector but neither of those things helped.

It is my understanding that the car has 3 16A chargers. Maybe one of them is broken.

Is there anything else that I can try before scheduling a service appointment?
 

Attachments

  • 15C91844-3649-4FAF-A1AA-B9290F531F39.jpeg
    15C91844-3649-4FAF-A1AA-B9290F531F39.jpeg
    327.8 KB · Views: 321
  • 6C2393D5-CBF2-496D-8DC3-41AE02418EDA.jpeg
    6C2393D5-CBF2-496D-8DC3-41AE02418EDA.jpeg
    289.5 KB · Views: 199
The charge port is clean and the cable is not getting hot. I actually had the charge pin replacement done last year during a mobile service visit.

Somehow my car's charge rate is getting worse. Now it maxes out at 16A.

I have scheduled a service appointment but the soonest that I can get in is June 3rd. Hopefully it doesn't fail completely between now and then.
 
I had something similar on my 2018 Model 3 about one year after delivery. It dropped from charging at 40 amps on my OpenEVSE unit to only 32 amps. It would start ramping up the current, drop back to 1 or 2 amps, and repeat several times. Eventually throwing a “charge rate reduced” alert and ramping up to 32 amps.

I contacted Tesla. They initially thought it was working as normal and that I was simply using the Tesla Mobile Connector, which is limited to 32 amps. After addressing that confusion, they wanted the vehicle at the shop located 3 hours away instead of sending a mobile service technician. I set an appointment for a month in the future when I would be driving through Kansas City already. The invoice says that they “Replaced PCS and performed vacuum coolant purge and two toolbox air purges. Verified vehicle charges as designed.” The PCS is the high voltage “doghouse” on the battery under the rear seat and contains the on-board charger. This was an all-day service appointment.

Edit: In my case, the issue only impacted A/C charging, not Supercharging.
 
When you start charging, take a look at the screen to see if the voltage goes down.
Chances are that there is a bad/lose connection somewhere, maybe at the breaker or the charger itself.
Other than that, what sduck said. Narrow it down by charging somewhere else.
 
  • Helpful
Reactions: Dave EV
When you start charging, take a look at the screen to see if the voltage goes down.
Chances are that there is a bad/lose connection somewhere, maybe at the breaker or the charger itself.
Other than that, what sduck said. Narrow it down by charging somewhere else.

A friend who also owns a Model 3 LR stopped by last night and tested charging his car using my Wall Connector. His car charged at the full 48A for about 30 minutes without any issues so I am pretty sure that the problem is with my car and not my Wall Connector.
 
You could try charging it at a supercharger or some other charging outlet to see if it's the car, or if there might be some issue with your home charger system.

For reference, this isn't always a clear cut problem solver. A Wall Charger inputs AC power and the charging system in the car converts to DC power, then to battery. A Supercharger will route DC power to battery basically, bypassing the AC system. If you're having charging issues at home, going to a Supercharger will only help determine if its battery pack (AC charge won't work, DC charge won't work) or penthouse related. It won't give you a clear cut AC system vs Wall Charger answer.
 
Just had this same issue with my 2018 Model 3 LR - throwing a "charge rate reduced" message. Milford service center replaced the PCS and all is well. They seemed to suspect that coming in so they had probably reviewed the logs already and/or it's a pretty typical failure.
 
I got my car back from the local Tesla Service Center. They determined that the power conversion system was faulty and had to be replaced. The part number of the part that was replaced is below.

ASY,PCS,48A,1PH,MDL3(1135558-00-D)
I'm getting the same symptoms. I tried a local level 2 wall charger in a town close by to verify that it wasn't my home charger acting up and sure enough it did the same thing, tried to charge at 48A then 32A then settled on 16A with the accompanying "Charge rate reduced, Unplug and retry". I tried to contact then through roadside assistance number but not available on Sundays I guess, I'll try tomorrow and see what they say. My car is out of warranty except for the battery and power train, did you get yours done on warranty? The PCS looks like it's a very expensive component.
 
I'm getting the same symptoms. I tried a local level 2 wall charger in a town close by to verify that it wasn't my home charger acting up and sure enough it did the same thing, tried to charge at 48A then 32A then settled on 16A with the accompanying "Charge rate reduced, Unplug and retry". I tried to contact then through roadside assistance number but not available on Sundays I guess, I'll try tomorrow and see what they say. My car is out of warranty except for the battery and power train, did you get yours done on warranty? The PCS looks like it's a very expensive component.
Yes, my PCS replacement was covered under warranty. I would think that the PCS would be considered part of the power train.
 
Yes, my PCS replacement was covered under warranty. I would think that the PCS would be considered part of the power train.

That's good to hear, but are you still inside of the standard 50,000 miles warranty? I'm at 109,000km (67,000 miles). I hope you're right about it being part of the battery warranty. I'll be sure to post the outcome.
 
  • Informative
Reactions: Arctic_White
Yes. My car is still under 50k miles.
I spoke to Tesla this morning via their Roadside Assistance number who then connected me to technical support (this seems to be the only way to contact them by phone although I wasn't "roadside" and stuck somewhere). As expected they were able to view the failure messages and ended up suggesting I book a service appointment. BTW, the women I spoke to thinks that this should be covered under the battery warranty. For now I have a Mobile Service appointment for July 14th. I thoroughly described the symptoms including trying other AC chargers and SCing so it wouldn't surprise me if it was changed to a Service Center visit.