Charging limited to 16a

[Leyendaz]

Good morning, I've seen this discussed months ago from what I have found, but never really found a solution. I do have a service date set.

My M3 only will go to charge at 16a instead of 32a all of a sudden when home. It has been fine for over 3 years and over 110k miles.

My wife's M3 has no issues using the same equipment. I've tried swapping out my charger for hers and its the same result.

Has anyone actually found out what the problem is? Thanks for any insight.

 

[lUtriaNt]

Power Conversion System (PCS) failure

There are a few threads going here and on other forums for charging issues that turn out to be PCS failures. Most owners notice the failure when they are AC charging (Wall Charger or Mobile Connector). The charge rate will drop from 48A to 32A or 32A to 16A and give an error message saying...

teslamotorsclub.com

The PCS has three 16A controllers, one operating gives you 16A, two operating gives you 32A and all three operating gives you your full 48A. If you are using a Wall Charger set up for 48A and one controller fails your rate is reduced to 32A...

 

[GtiMart]

What the previous post said, with one comment: if you have an SR+ I believe you only have two 16A modules for a total of 32A, and one of them is probably faulty.

 

[Leyendaz]

Power Conversion System (PCS) failure

There are a few threads going here and on other forums for charging issues that turn out to be PCS failures. Most owners notice the failure when they are AC charging (Wall Charger or Mobile Connector). The charge rate will drop from 48A to 32A or 32A to 16A and give an error message saying...

teslamotorsclub.com

Thank you for this. Sounds like my issue. Only thing is it never even goes to 32a, it will spike at 20a and then just chill at 16-17a.

 

[Leyendaz]

What the previous post said, with one comment: if you have an SR+ I believe you only have two 16A modules for a total of 32A, and one of them is probably faulty.

It's a 2018 Long range RWD. Prob only two.

 

[GtiMart]

Hum... I think long range can charge on 48A, like the dual motor, since it has the big ~75-78kWh battery. But I'm not 100% sure.

 

[AlanSubie4Life]

Good morning, I've seen this discussed months ago from what I have found, but never really found a solution. I do have a service date set.

My M3 only will go to charge at 16a instead of 32a all of a sudden when home. It has been fine for over 3 years and over 110k miles.

My wife's M3 has no issues using the same equipment. I've tried swapping out my charger for hers and its the same result.

Has anyone actually found out what the problem is? Thanks for any insight.

Could be a bad contact or other issue in the charge port. See for example the cases where the deadfronts get stuck in the port so the handle won’t seat, but it will still charge at 16A (displays another error in the car though, so not the case here).

Or maybe two of your PCS modules have failed. Probably not though.

Still, I’d visually inspect the charge port, make sure the setting in the car is not limiting it (unlikely), etc.

So no warning/error messages?

 

[Leyendaz]

Could be a bad contact or other issue in the charge port. See for example the cases where the deadfronts get stuck in the port so the handle won’t seat, but it will still charge at 16A (displays another error in the car though, so not the case here).

Or maybe two of your PCS modules have failed. Probably not though.

Still, I’d visually inspect the charge port, make sure the setting in the car is not limiting it (unlikely), etc.

So no warning/error messages?

I've seen the error message that says something like "try another source or reconnecting" only twice over the course of ~2 months this has been an issue. I don't really stay in the car and wait much however. It's a rare error message.

I just went out to check and I didn't notice anything inside, I even tried blowing it out with my electric air duster the other day. Looks fine inside, no different than wife's car.

I take it in for service next week for this, I'll report what they tell me here. Thanks for the replies!

 

[Leyendaz]

Hum... I think long range can charge on 48A, like the dual motor, since it has the big ~75-78kWh battery. But I'm not 100% sure.

When I am charging at home the + under the 32a is greyed out, so maybe not, also on wife's car which is 2019 LR RWD.

 

[AlanSubie4Life]

When I am charging at home the + under the 32a is greyed out, so maybe not, also on wife's car which is 2019 LR RWD.

It’s limited by the UMC in that case (32A). When plugged into charge equipment the max is limited to the maximum charge rate supported by the equipment (or 48A, if that is lower). You can charge at 48A (if it weren’t broken, anyway).

That error message should not occur. Again, sounds like a problem with the charge port. My assessment is that your car is broken. Fortunately it still charges!

I guess you could try a supercharger which would rule out certain pieces being the issue (but not the PCS of course).

 

[Big Dog]

The 2018 LR can charge up to 48 amps if you have a 60 amp circuit and use the Tesla Wall Charger.

 

[rrolsbe]

I had my PCS board replaced recently after observing AC charging problems. The normal ramp up during AC charging oscillated up and down before stabilizing; likewise, if you attempted to AC charge at rates higher than 32A (via a wall connector/destination charger), it would only charge at 32A with a bad grid power error message. The replacement PCS board solved both of these problems.

This is the part number of the replacement board ASY,Power Conversion System,PCS,48A,1PH(1135558- 00-D).

I am not sure what the rev number of the old board was but I assume it was probably rev A or B for a build date of June 2018? If Tesla identified a problem with the early revs of the PCS board, maybe rev D resolves such issues? anyone have any insight on rev version changes?

Thanks for any insight in advance!
Regards, Ron

 

[FlyingPenguino]

Good morning, I've seen this discussed months ago from what I have found, but never really found a solution. I do have a service date set.

My M3 only will go to charge at 16a instead of 32a all of a sudden when home. It has been fine for over 3 years and over 110k miles.

My wife's M3 has no issues using the same equipment. I've tried swapping out my charger for hers and its the same result.

Has anyone actually found out what the problem is? Thanks for any insight.

I had this happen to my 2016 MX after the MCU2 Computer lobotomy, er, I mean upgrade (or after the subsequent software upgrades that were now unlocked after the MCU2 swap). I read this thread and then called Tesla for tech support (choose the Supercharging support option - I believe that's a 24 hour help line). Scott was a super-helpful tech who read up on the issue - specifically with my ChargePoint Home (although I think this happens with other brands of at-home chargers). He read that I should try a hard reset of the ChargePoint back to factory defaults and that worked for someone else. Scott was right on the money. After trying all of the Tesla-side possible fixes, the factory reset took 5 min and worked like a charm. Back to 40A of charging capabilities at home - just like before!

 

[FlyingPenguino]

Power Conversion System (PCS) failure

There are a few threads going here and on other forums for charging issues that turn out to be PCS failures. Most owners notice the failure when they are AC charging (Wall Charger or Mobile Connector). The charge rate will drop from 48A to 32A or 32A to 16A and give an error message saying...

teslamotorsclub.com

I had this happen to my 2016 MX after the MCU2 Computer lobotomy, er, I mean upgrade (or after the subsequent software upgrades that were now unlocked after the MCU2 swap). I read this thread and then called Tesla for tech support (choose the Supercharging support option - I believe that's a 24 hour help line). Scott was a super-helpful tech who read up on the issue - specifically with my ChargePoint Home (although I think this happens with other brands of at-home chargers). He read that I should try a hard reset of the ChargePoint back to factory defaults and that worked for someone else. Scott was right on the money. After trying all of the Tesla-side possible fixes, the factory reset took 5 min and worked like a charm. Back to 40A of charging capabilities at home - just like before!

 

[TTD1]

Good morning, I've seen this discussed months ago from what I have found, but never really found a solution. I do have a service date set.

My M3 only will go to charge at 16a instead of 32a all of a sudden when home. It has been fine for over 3 years and over 110k miles.

My wife's M3 has no issues using the same equipment. I've tried swapping out my charger for hers and its the same result.

Has anyone actually found out what the problem is? Thanks for any insight.

A little food for thought here. Have a 2019 S100D with the factory supplied (Tesla branded) charging cable and 14-50 adaptor. Charging by 240V 50A circuit with 14-50 receptacle. Charging always starts at 32A but drops back to 16A after a short time. This was driving me nuts, of course, so I looked everywhere for a cause. I happened to examine the Tesla 14-50 plug on the adaptor and discovered that it was rated at 30A. WTF. As an experiment I bought an aftermarket (not Tesla branded) 14-50 adaptor, which came with a larger diameter cord and a properly rated (50A plug). I've only used the new one once for several hours (47%-80%), but it never dropped below the 32A max. We'll see going forward...

 

[Rocky_H]

I happened to examine the Tesla 14-50 plug on the adaptor and discovered that it was rated at 30A. WTF.

That's been known about for many years. It's some kind of certification/labeling thing and isn't relevant to the current dropping off. It is intended to run at 32A, and they do.

 

[TTD1]

That's been known about for many years. It's some kind of certification/labeling thing and isn't relevant to the current dropping off. It is intended to run at 32A, and they do.

They run at 32A, except when they don't, which is about half the time. I'll continue the experiment with the new adaptor, and report back.

 

[Rocky_H]

They run at 32A, except when they don't, which is about half the time.

You having problems with your adapter is one thing. And it is a very rare thing. It is not anywhere close to "half the time" for the general population of many tens of thousands of owners who use those adapters daily. Please don't do that.

 

[TTD1]

You having problems with your adapter is one thing. And it is a very rare thing. It is not anywhere close to "half the time" for the general population of many tens of thousands of owners who use those adapters daily. Please don't do that.

I'm only GUESSING that the adaptor is the problem with my car, but I will find out soon enough. By the way, we love this car and will be buying it when the lease is up in July. Yes, it has it's quirks like any car, and if it's something as annoying as this charging issue, I may well vent my frustrations. BTW, there are a lot more than a handful of Tesla owners out there with this issue.

 

[jwharnish]

I'm only GUESSING that the adaptor is the problem with my car, but I will find out soon enough. By the way, we love this car and will be buying it when the lease is up in July. Yes, it has it's quirks like any car, and if it's something as annoying as this charging issue, I may well vent my frustrations. BTW, there are a lot more than a handful of Tesla owners out there with this issue.

This 16 amp charge rate was discussed on a previous thread that dealt with NEMA 14-50 plugs. If the car starts to charge at the normal expected rate then drops back down to 16amp, that was due to over heat sensor at the plug. 16amp seemed to be a default number when over heating was detected.
In most cases it was due to an inferior plug being used. Leviton was one of the brands that was often sited for over heating issues. Once replaced with a Hubbell or similar quality plug the problem was resolved.
I had this same issue and that was fixed when I switched the Leviton out for the Hubbell.