Charge Speed Reduced, unplug and try again

[darth_vad3r]

IIRC, the 32 A and 48 A AC charging capabilities of the 3 SR/+ and LR are implemented with multiple individual 16 A AC on-board chargers (x2 for 32 A or x3 for 48 A).

So if you see a drop to a max of exactly 16 or 32 A (from 32 or 48 A) a failed charger seems likely.

Luckily, it seems like you can still AC charge if something goes wrong with a charger (or two on the LR)!
Also luckily, you can probably still DC charge (Supercharge/CHAdeMO/CCS) if the problem is isolated to the on-board AC charging system since the “DC charger” is outside of the car in the station

 

[buddhra]

Count me in as well. I just had the same part replaced on mine and the service center mentioned I was the second one in two weeks, so this may be more widespread than it seems. Which that makes sense when most people aren't charging above 32A anyway or if they do, it's probably at night when they won't see the message. When I looked back at my power bill, I've been limited to 32A for months and didn't know. Here's a little video to summarize and try to spread the word.

 

[Steparke]

This problem started tonight for me. I use my 120 volt outlet and get 5-6 mph charging. I received the charging limited message and now I am charging at only 3mph. Ive tried difi outlets and rebooted etc. No luck,I have now scheduled a service appointment.

 

[tizio]

Same problem here with a M3-Dual from late 2018.
Service appointment is in a few days. The mobile charger doesn't work at all and the HPWC only charges at 14A out of 48A.
Not the end of the world based on how we use this car, but we found out the hard way the mobile charger didn't work when we plugged it in at airport parking for 5 days and came back to 20%.

 

[Shirt4878]

Same issue as others on my 04/2019 build SR+, I noticed the issue when chargining on a Chargepoint J1772 charger that I use regularly. The car kept cutting the charging speed to 16 amps vs the full 32 amps as the state of charge reached about 75%.
I was getting both errors in the car "Low quality grid detected" and "Charge speed reduced, unplug and try again".

Supercharging was working fine, and also charging with the mobile connector at 20 amp x 120V was fine.

Took it into service and they confirmed they will replace the power conversion system under warranty.

 

[GenoM3P]

Me too, tonight. Perfect 44 mi/hr at 48 amps since 9/18. Suddenly max at 32. Same error messages. Scheduled service next Thursday. Can't really complain. 1st issue I've had.

Geno

 

[ACPark]

Just happened to my 2018 M3P. First time charging 16/48 A, all other times 32/48 A. Booked service.
PCS_a019 error shows under the details of the error.

Glad they seem to have some redundancy. Heading on a trip before service is available.

 

[jtpassat]

Just happened to me. Charging is limited to 16 amps vs the usual 32. Scheduled for service on Wed so let’s see if it’s the same power conversion fix.

 

[4point9]

Just happened to me also. LR RWD 2018. I get the "Charge Rate reduced" for anything over 32 amps. Local Service centre replied with:

"We have spoken to engineering and they have determined the issue that is occurring with charging is related to a known firmware bug. They are diligently working on a solution and will update your vehicle with a firmware revision as soon as its ready. This is a high priority and should be resolved shortly. As a technician is not required we will close this request, however your vehicle has been flagged to require the firmware fix when ready."...
​

I guess I'll give this a bit of time and post the final outcome.

 

[4point9]

Just happened to me also. LR RWD 2018. I get the "Charge Rate reduced" for anything over 32 amps. Local Service centre replied with:

"We have spoken to engineering and they have determined the issue that is occurring with charging is related to a known firmware bug. They are diligently working on a solution and will update your vehicle with a firmware revision as soon as its ready. This is a high priority and should be resolved shortly. As a technician is not required we will close this request, however your vehicle has been flagged to require the firmware fix when ready."...
​

I guess I'll give this a bit of time and post the final outcome.

Update: I ended up calling Tesla Home Charging support (just follow the options from the main Tesla phone #). It took 90 min on hold but I got connected to a very helpful knowledgeable home charging specialist. He was able to remote to the car, see the detailed logs, and even call up a month earlier when I had charged at a public charger and saw the same 32 amp current limit. He had me connect the mobile charger that came with the car to a 120 v outlet - and it wouldn't charge at all with that. A case # was created and I was advised to give this case # to the local service centre. The specialist said that every indication is that this problem is hardware related and I was advised to contact my service centre again, with the diagnostics recorded under the case#. So now waiting to have the car go in for service. (I suspect it will be the Power Conversion System like all the other posters have had). Will report back on final outcome.

 

[4point9]

Update: I ended up calling Tesla Home Charging support (just follow the options from the main Tesla phone #). It took 90 min on hold but I got connected to a very helpful knowledgeable home charging specialist. He was able to remote to the car, see the detailed logs, and even call up a month earlier when I had charged at a public charger and saw the same 32 amp current limit. He had me connect the mobile charger that came with the car to a 120 v outlet - and it wouldn't charge at all with that. A case # was created and I was advised to give this case # to the local service centre. The specialist said that every indication is that this problem is hardware related and I was advised to contact my service centre again, with the diagnostics recorded under the case#. So now waiting to have the car go in for service. (I suspect it will be the Power Conversion System like all the other posters have had). Will report back on final outcome.

 

[ACPark]

Update: I ended up calling Tesla Home Charging support (just follow the options from the main Tesla phone #). It took 90 min on hold but I got connected to a very helpful knowledgeable home charging specialist. He was able to remote to the car, see the detailed logs, and even call up a month earlier when I had charged at a public charger and saw the same 32 amp current limit. He had me connect the mobile charger that came with the car to a 120 v outlet - and it wouldn't charge at all with that. A case # was created and I was advised to give this case # to the local service centre. The specialist said that every indication is that this problem is hardware related and I was advised to contact my service centre again, with the diagnostics recorded under the case#. So now waiting to have the car go in for service. (I suspect it will be the Power Conversion System like all the other posters have had). Will report back on final outcome.

Had you taken your vehicle into service for evaluation before this call?

 

[4point9]

Had you taken your vehicle into service for evaluation before this call?

Update: Tesla mobile service reviewed the Case# and is confident this is still a firmware bug that will be fixed with a new push. The inability to charge at 120 V on the mobile connector was just a scheduled timing issue - now charging fine on Level 1 120V with 2 different chargers. So must wait for some firmware releases. I cannot get past the online booking of a service call to have a service centre look at this in the shop - at least not until its demonstrated that some future pending firmware update.

 

[ACPark]

Update: Tesla mobile service reviewed the Case# and is confident this is still a firmware bug that will be fixed with a new push. The inability to charge at 120 V on the mobile connector was just a scheduled timing issue - now charging fine on Level 1 120V with 2 different chargers. So must wait for some firmware releases. I cannot get past the online booking of a service call to have a service centre look at this in the shop - at least not until its demonstrated that some future pending firmware update.

Thanks.

I've brought mine in twice and the SC was very accommodating both times. I pressed for details and provided as much info as I could based on my charging experience, and home charger setup.

I was also ultimately informed the issue is firmware. They indicated the PCM is too sensitive to power quality, and rejecting charging.

 

[4point9]

Thanks.

I've brought mine in twice and the SC was very accommodating both times. I pressed for details and provided as much info as I could based on my charging experience, and home charger setup.

I was also ultimately informed the issue is firmware. They indicated the PCM is too sensitive to power quality, and rejecting charging.

Thanks - That is great info. I dropped by my local SC today as well and the tech. pulled logs and investigated. I also provided the case # for the chat I had with Tesla Home Charging. The conclusion was the same - that the issue is firmware and we must wait for a fix. I wasn't able to get as many details as you did - so thanks for that. The SC didn't have an ETA on when firmware would be ready, but in my original mobile service chat they indicated it "should be resolved shortly". I guess we just have to be patient and sit tight...

 

[Rocky_H]

The SC didn't have an ETA on when firmware would be ready, but in my original mobile service chat they indicated it "should be resolved shortly". I guess we just have to be patient and sit tight...

"shortly" is the new "soon"

 

[Sans-gas]

Has anyone noticed that there are several posts from a year ago regarding this same issue? If Tesla diagnosed it then and replaced the PCS in those, why is our issue NEW we’re waiting for a firmware fix? These were 2018 M3 LR, as I recall.

I would love to have had them replace a part when I had it in service last week rather than waiting for a fix to be programmed.

 

[4point9]

Is anyone with firmware 2020.36.15 had their charging problems fixed?
I got 36.15 two days ago and still cannot charge over 32 amps, but I've seen a couple reports saying it fixed the issues for some people.

 

[StanT]

I have a MY with a Tesla charger, 60amp breaker but I usually just charge at 35 amps... yesterday just got the error message for the first time 32amps vs my normal 35... I unplugged.. re-plugged... unplugged... replugged and I was back to 35amps.... then charged during the day today, no problem... got home, plugged in... got the message and its stuck at 16Amps. Tried the disconnect, reconnect again, but still stuck at 16amps. I am version 10.2 (2020.36.4 ) but I had the install for 2020.36.11 prompting me. So while I was stuck at 16amps I installed 36.11. After the install it jumped up on its own to 32Amps. I'll find out tomorrow if it will go up to 35, but I'm going to leave it at 32 tonight because I really need to charge it up tonight.

 

[ACPark]

Has anyone noticed that there are several posts from a year ago regarding this same issue? If Tesla diagnosed it then and replaced the PCS in those, why is our issue NEW we’re waiting for a firmware fix? These were 2018 M3 LR, as I recall.

I would love to have had them replace a part when I had it in service last week rather than waiting for a fix to be programmed.

Sure did notice this.

Since I don't believe it's incompetency on Tesla's part.

I suspect Tesla 'hopes' they can resolve the issue with a firmware change rather than a part change. This could be due to them making a firmware change that caused the issue, or to save money on an issue that has become more prevalent.

I suppose the required firmware change could be in the PCM or in the HPWC.

I noticed this issue first after update 2020.28.5
The issue has been intermittent. Currently charging at 235 V @ 48/48 A on firmware 2020.36.15