Power Conversion System (PCS) failure

[gearchruncher]

The nature of most TSBs is that the manufacturer does not bring it up as an issue nor proactively fix it unless the customer complains of it as an issue.

So let's say that the front motor in your AWD car stops working. The car still drives fine, so Tesla gives you no warnings or indications.
Then you take the car in for another issue while the car is under warranty. They see the error code, but you haven't complained, so they don't repair it.

Is this situation different?

This is not a suspension clunk or driveshaft vibration at full throttle. This is an electronic module in the car which has unquestionably failed, the car no longer meets the original design intent, and is absolutley covered under warranty as a failure as long as you notice it. You're cool with Tesla not telling you it's failed via a message to the driver, requiring you to identify it in a way that is not possible with any of the equipment Tesla provided with the car, and also not telling you if you bring the car in for service?

This really has nothing to do with a TSB, which is how or when to repair something that has become a common issue in the fleet but may not represent a warranty issue (like a rattle) but TSB's are not about how to hide a failed component from the owner. What would a TSB even say in this case? "PCS's fail now and then, follow the repair manual to replace it, and if it's out of warranty pretend that it's not insde the battery when charing the customer $1800 to replace something that should be under the 8 year warranty but isn't because reasons?"

 

[android04]

Not exactly. When charging at 16a or lower, the OBC uses only one module, and when charging at 32a or lower, it uses only 2 modules, so charging at 32a would load two modules at full capacity, leaving one idle. I suspect they do this to avoid running modules at low amperages where they might be less efficient. A side effect of this is that you can have a module go bad, keep charging at 32a without a clue that anything's wrong, and not find out until after the warranty is over because you happen to try 48a charging one day.

I don't remember the exact behavior and would have to look up pictures I took, but about 3 years ago I got to play around with real Service Mode in my Model 3 and tested charging at multiple amp values from as low as I could set it to 48A on my wall connector. From what I saw, the current would divide evenly between two of the three "phases" (as Tesla called the 3 charger components in Service Mode). Evenly between two "phases" when equal to out less than 32 amps, and evenly between the three "phases" when above 32 amps. Can't recall the exact behavior below 16 amps, but I think they were evenly divided as well. They was even a counter that kept track of how many hours each "phase" had been used.

 

[stopcrazypp]

So let's say that the front motor in your AWD car stops working. The car still drives fine, so Tesla gives you no warnings or indications.
Then you take the car in for another issue while the car is under warranty. They see the error code, but you haven't complained, so they don't repair it.

Is this situation different?

That situation is different because it's a safety issue (due to being part of drivetrain), and could be claimed part of a recall.

The closer analogy is for example a less critical component during driving, like if you have a failing USB port that throws an error in an error log somewhere, but the computer does not notify you with a very obvious message. Then you never know you need to get it fixed until you actually use that USB port.

This is not a suspension clunk or driveshaft vibration at full throttle. This is an electronic module in the car which has unquestionably failed, the car no longer meets the original design intent, and is absolutley covered under warranty as a failure as long as you notice it. You're cool with Tesla not telling you it's failed via a message to the driver, requiring you to identify it in a way that is not possible with any of the equipment Tesla provided with the car, and also not telling you if you bring the car in for service?

Well I'm not saying I'm cool with it, just that that is typically how TSBs are noted.

This really has nothing to do with a TSB, which is how or when to repair something that has become a common issue in the fleet but may not represent a warranty issue (like a rattle) but TSB's are not about how to hide a failed component from the owner. What would a TSB even say in this case? "PCS's fail now and then, follow the repair manual to replace it, and if it's out of warranty pretend that it's not insde the battery when charing the customer $1800 to replace something that should be under the 8 year warranty but isn't because reasons?"

TSBs tend to have very similar wording. Basically it says if a customer complains about this issue, then fix it. Otherwise they don't proactively bring it up, even though it may be that the same issue likely affects most if not all cars.

 

[gearchruncher]

That situation is different because it's a safety issue (due to being part of drivetrain), and could be claimed part of a recall.

How is loss of the front motor a safety issue? Tesla will literally sell you the car without the front motor. Are you saying when Tesla sells a RWD car it's unsafe?

Of course your can convolute a situation where thinking you had AWD and not could be dangerous. You can do the same for thinking you can charge at 48A but can only charge at 16A. (Tesla doesn't warn you for two failures either)

And just because something is "drivetrain" does not mean it's safety related. This is why I brought up CV joints that shuddder at high power, which is common in the Model X. Tesla says this is "in spec" on the car, despite it clearly not being the design intent and since not all cars do it, is indicative of an individual car having a problem.

Explain why Tesla does this:
1) Shows you right on the screen what the charge equioment can charge at (32/32A), so you can tell what the charge equipment is capable of
2) GIves you a warning for slow charing if the charge equipment is not performing
3) Gives you a warning if the voltage sags and limits charge rate
4) Gives you a warning if the battery is cold and you can't charge at full rate
5) Gives you a warning if the charging is limited because the wall outlet is hot.
6) Gives you a warning if the grounding is insufficent to charge

Tesla literally has 100 different messages listed in the Model 3 Manual that tell you why charging is not working as expected. This is about 75% of all messages possible in the car. All the above let you diagnose why charging is slower than expected and resolve it. Note that none of these cost Tesla money.

Yet, the one message they are curiously missing is this: "Charging speed reduced as charge system has partically failed. Contact Tesla for service."

And yet the car has all of these warnings:
"Maximum charge level and range may be reduced OK to drive - Schedule service soon" (how is that safety?)
"High voltage battery requires service Acceleration and charging performance reduced" (hmm, they do warn for charging performance in some cases)
"Gearbox fluid service recommended Schedule Service" (makes tesla money)
"Electrical system is unable to support all features Schedule service" (how is this not the PCS charge failure also?)

And the best one:

"Service is required Schedule service now"

The fact that a PCS charge module failure is missing is glaring against the depth and precision of messages they do have.

 

[MP3Mike]

"Service is required Schedule service now"

The fact that a PCS charge module failure is missing is glaring against the depth and precision of messages they do have.

I thought that they do now show an alert to you, as long as you are trying to charge at a rate that uses a failed module. (So, if one module had failed and you were charging above 32A it would show an error.)

 

[nicksp]

Dumb question. So the PCS has 3 levels when the appropriate current is available. 16, 32 and 48. So any 2 can randomly stop working or is it normally in any order? And suppose it stops charging at any level, does it mean the PCS is on its way out?

 

[Big Earl]

They work in parallel. Any one of the three boards failing will result in a reduction of 16 amps. Two of the three boards failing will result in a 32 amp reduction in charging, or no charging at all if you have a standard range Model 3 or Y.

 

[davewill]

Dumb question. So the PCS has 3 levels when the appropriate current is available. 16, 32 and 48. So any 2 can randomly stop working or is it normally in any order? And suppose it stops charging at any level, does it mean the PCS is on its way out?

Also, just because one module has failed does not mean the PCS is "on it's way out." It's quite possible that the two remaining modules will work forever. They are not put under extra strain, the car will just be limited to 32a charging.

 

[MP3Mike]

Also, just because one module has failed does not mean the PCS is "on it's way out." It's quite possible that the two remaining modules will work forever. They are not put under extra strain, the car will just be limited to 32a charging.

True, but we have seen reports of some PCS with one module failing after another until the vehicle could no longer AC charge. (It seems to me like there was either a design issue or a "bad" batch of parts. Which have hopefully been corrected.)

 

[gearchruncher]

I thought that they do now show an alert to you, as long as you are trying to charge at a rate that uses a failed module.

I did not get an error two years ago, and the manual does not list this as one of the possible failures, but happy to be corrected if they now tell people.
Would still be scummy if they only tell you when you go to use 48A since the car only comes with a 32A charge cable.

 

[MP3Mike]

I did not get an error two years ago, and the manual does not list this as one of the possible failures, but happy to be corrected if they now tell people.
Would still be scummy if they only tell you when you go to use 48A since the car only comes with a 32A charge cable.

A few examples from this thread:

Hmm.....after 4 years of using the mobile charger in my June 2018 build Model 3, I installed an HPWC this weekend. Went to test it out and the message about "Charging slowed..." message. Had me wondering if I messed up the install. I checked everything and it seems good. So started to search about the problem, and found all you guys. Ugh. I have always gotten the full 32a out of the mobile charger, so had no issues. Now with the HPWC, I could do up to 40a, but the car just shows it still using only 32/40 and the "charging slowed..." message. I am guessing I am having this issue as well, and didn't even know it.

+1 Here. Like others, I just recently upgraded to a gen3 wall connector after charging with a mobile connector for the past 4 years and immediately got throttled to 32amps with the PCS alert. First available service appointment is a month away.

And here is you even responding to someone about you not knowing about the alert:

That's a new one. I don't think anyone here has reported getting a PCS alert for a car that can do 32A. Only for the ones that fail twice down to 16A.

And another one:

OK, I'll add my data point for my 2018 LR RWD. This past July during a road trip, three months after my battery warranty expired, I plugged into a greater than 24amp EVSE for the first time in over a year. Tried to charge at 48amps, but soon threw the dreaded PCS_a019 error and it backed down to 32amps @200VAC (why the voltage drop from 240VAC ???).

Of course, the text on the alert is misleading, since I think it says something like: charging slowed unplug and try again later. But I would think after someone has tried over a couple of days, with the same result, that they would open a service request with Tesla and they would tell them that the PCS needs replaced.

Tesla really need to do better: (I normally agree with most of what Tesla does, but in this case they are handling it completely wrong.)

• They need to update the alert text to be more appropriate. (Maybe "PCS charger module failed, charging speed reduced, schedule service for repair" or something similar.)
• They need to show the alert as soon as they detect a failed module, even if you are only charging at 5A. (We know that they cycle through the different modules to even out usage.)
• They need to cover the repair under the battery warranty. (It is clearly inside the HV battery, and there is no exclusion in the HV battery warranty for the PCS.)
• They need to refund everyone that has paid for a PCS replacement where they still had an active HV battery warranty.

But the only way I see that happening at this point is if more people file an arbitration claim, even if they lose it costs Tesla more in arbitration fees than they charge for the PCS repair, people suing in small claims court, or someone starts a class action lawsuit.

I do hope that this issue is at least limited to older Model 3s, and that it has been fixed in current revisions of the PCS.

 

[chrishutchins]

Has anyone had a full failure of all 3 PCS boards? I don't know when the first of mine failed (2018 M3), but the 2nd failed this past October and I'm wondering how risky it is to not get it repaired ($1900 estimate at my SC).

 

[miimura]

Has anyone had a full failure of all 3 PCS boards? I don't know when the first of mine failed (2018 M3), but the 2nd failed this past October and I'm wondering how risky it is to not get it repaired ($1900 estimate at my SC).

If you have a nearby DC charger, then it's not a big deal. If you don't have any convenient way to charge except AC at home, then you had better get it fixed sooner than later.

 

[ucmndd]

Has anyone had a full failure of all 3 PCS boards? I don't know when the first of mine failed (2018 M3), but the 2nd failed this past October and I'm wondering how risky it is to not get it repaired ($1900 estimate at my SC).

There was pretty clearly a bad batch of these things. You’ve had a 66% failure rate so far. I’d say it’s when not if.

 

[jjrandorin]

Has anyone had a full failure of all 3 PCS boards? I don't know when the first of mine failed (2018 M3), but the 2nd failed this past October and I'm wondering how risky it is to not get it repaired ($1900 estimate at my SC).

This is pretty much the equivalent of putting a sticky note over a check engine light in an ICE vehicle, except you already know what the issue is and the cost to repair.

 

[stopcrazypp]

How is loss of the front motor a safety issue? Tesla will literally sell you the car without the front motor. Are you saying when Tesla sells a RWD car it's unsafe?

Of course your can convolute a situation where thinking you had AWD and not could be dangerous. You can do the same for thinking you can charge at 48A but can only charge at 16A. (Tesla doesn't warn you for two failures either)

And just because something is "drivetrain" does not mean it's safety related. This is why I brought up CV joints that shuddder at high power, which is common in the Model X. Tesla says this is "in spec" on the car, despite it clearly not being the design intent and since not all cars do it, is indicative of an individual car having a problem.

It's a safety related issue because it's related to the drivetrain, which makes it potentially eligible for a recall. For example, the same issue can potentially mean the motor may fail while car is driving and that can cause an accident if it happens at the wrong time. CV joint also can potentially qualify for a recall (in fact I'm pretty sure there are people pushing for similar issues to be covered under recall).

The difference for the current PCS failure is that only the charging circuit is failing and it only comes into play while the car is in park and doesn't create a danger for driving (nor does it mean the car catches on fire for example when stationary). That's basically the logic others brought up why PCS charging failure will never qualify for a recall, it's not mine.

If you can come up with a logical reason for the PCS to qualify as a safety-related defect, I think a lot of people will thank you. Even something people can put into a NHTSA safety report would be quite helpful:
Report a Safety Problem | NHTSA

Looking at that page, it even gives an example of what qualifies and what doesn't:
"An example of a safety-related defect is a steering component that breaks, causing a driver to lose control. However, an air conditioner that does not work properly isn't considered a safety-related defect, because it does not pose a risk to motor vehicle safety."

Explain why Tesla does this:
1) Shows you right on the screen what the charge equioment can charge at (32/32A), so you can tell what the charge equipment is capable of
2) GIves you a warning for slow charing if the charge equipment is not performing
3) Gives you a warning if the voltage sags and limits charge rate
4) Gives you a warning if the battery is cold and you can't charge at full rate
5) Gives you a warning if the charging is limited because the wall outlet is hot.
6) Gives you a warning if the grounding is insufficent to charge

Tesla literally has 100 different messages listed in the Model 3 Manual that tell you why charging is not working as expected. This is about 75% of all messages possible in the car. All the above let you diagnose why charging is slower than expected and resolve it. Note that none of these cost Tesla money.

Yet, the one message they are curiously missing is this: "Charging speed reduced as charge system has partically failed. Contact Tesla for service."

And yet the car has all of these warnings:
"Maximum charge level and range may be reduced OK to drive - Schedule service soon" (how is that safety?)
"High voltage battery requires service Acceleration and charging performance reduced" (hmm, they do warn for charging performance in some cases)
"Gearbox fluid service recommended Schedule Service" (makes tesla money)
"Electrical system is unable to support all features Schedule service" (how is this not the PCS charge failure also?)

And the best one:

"Service is required Schedule service now"

The fact that a PCS charge module failure is missing is glaring against the depth and precision of messages they do have.

Given there are so many messages, it's possible their engineers already covered it under a different message (as per the other response to you) or they just missed it. Or it could be they are not explicitly disclosing it to avoid covering it under warranty as you theorize, but as I noted that isn't uncommon for TSBs. Again, I'm not saying I'm ok with it, just that it's not unusual for manufacturers to do this.

 

[android04]

Not exactly. When charging at 16a or lower, the OBC uses only one module, and when charging at 32a or lower, it uses only 2 modules, so charging at 32a would load two modules at full capacity, leaving one idle.

I don't remember the exact behavior and would have to look up pictures I took, but about 3 years ago I got to play around with real Service Mode in my Model 3 and tested charging at multiple amp values from as low as I could set it to 48A on my wall connector. From what I saw, the current would divide evenly between two of the three "phases" (as Tesla called the 3 charger components in Service Mode). Evenly between two "phases" when equal to or less than 32 amps, and evenly between the three "phases" when above 32 amps. Can't recall the exact behavior below 16 amps, but I think they were evenly divided as well. They was even a counter that kept track of how many hours each "phase" had been used.

I went back and looked at the pictures I took of my car in Service Mode, where I tested charging at different currents. Dave is right that at 16A or less only one of the three "phases" or modules is used. Above 16A and up to 32A the current is divided evenly between two "phases" or modules. And above 32A the current is divided evenly between three "phases" or modules. Also, there is an counter for each module's lifetime KWH and it looks like the computer can control which ones get used in order to even out their usage.

For anybody that is curious, here are my pictures. Keep in mind that these were taken 27 months ago, and behavior could have been updated by Tesla through software updates. These are in the order that I took them, playing around with my Tesla HPWC at 240V and up to 48A. My car is Model 3 LR RWD that supports 48A charging.

Idle, not charging


Charging at 24 Amps, 240V


Charging at 34 Amps, 240V


Charging at 12 Amps, 240V

 

[Gtech]

I went back and looked at the pictures I took of my car in Service Mode, where I tested charging at different currents. Dave is right that at 16A or less only one of the three "phases" or modules is used. Above 16A and up to 32A the current is divided evenly between two "phases" or modules. And above 32A the current is divided evenly between three "phases" or modules. Also, there is an counter for each module's lifetime KWH and it looks like the computer can control which ones get used in order to even out their usage.

For anybody that is curious, here are my pictures. Keep in mind that these were taken 27 months ago, and behavior could have been updated by Tesla through software updates. These are in the order that I took them, playing around with my Tesla HPWC at 240V and up to 48A. My car is Model 3 LR RWD that supports 48A charging.

Idle, not charging
View attachment 1005335

Charging at 24 Amps, 240V
View attachment 1005336

Charging at 34 Amps, 240V
View attachment 1005337

Charging at 12 Amps, 240V
View attachment 1005338

Thank you for sharing

 

[CoolBuddy]

My PCS failure occurred after I spent over $1000 to have a certified electrician do the breaker and wiring upgrade and install a new wall connector. It sucks to spend that much when I could've just bought a second mobile connector and used the existing plug, breaker, and wiring without having to unplug the 240V adapter again and still charge with 32A. I had previously charged at 48A with no problems and am not completely convinced my Wall Connector didn't cause the failure as it seemed like a strange coincidence, but not sure how I'd prove it other than paying the approx $1700 Tesla quoted me to to replace the PCS module entirely. For me, I don't want to spend an extra $1700 just to find out and have a slightly faster home charging. I'll wait until the next block fails and I'm limited to 16A and hopefully the money invested instead of paying for the repair will have returned enough to effectively reduce the overall cost of the repair.

If any class action happens, I'd love to join in.

 

[Y Cmbust]

"but I don't get a (PCS) failure message until I have lost two out of the three controllers. By the time I lost two controllers I was outside the basic warranty."

If anyone else is attempting to get the $2500 repair, covered by Tesla, let me know your experience.

My PCS stopped charging above 40 Amps AC, while still under warranty, but did not give me any messages. It happened during a dealership motor replacement. I am reminded that this PCS is cooled with the same system as the battery. When I got it back from the dealership, the coolant was low and I couldn't charge above 16 Amp. And this, of course, suggests that they overheated the PCS by charging it either without coolant or with low coolant.

I recently had a tech scan the system and did find a PCS error warning, just before the expiration date. He Told me 2 of my three 16amp inverters had failed and a fuse was blown He was an able to review error codes older than one year. I find that hard to believe. Is there a way to get this information?

If anyone has knowledge of a tesla warehouse supplier who actually has and will sell me a PCS, please, please, please let me know. I live in Hawaii and the dealership here is too lazy to bother to find and order the part for me.

Mahalo!

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