2nd PCS2 failure

[Edphonse]

This is going to sound stupid but what is your normal charging regimen - charge every day? Every other day? Usage of supercharging? Long trips frequently? Anything unusual about your grid/power ?

My example:
- I have 48A 240V at home which I avoid using unless necessary. Once or twice a week to 50% only unless zapping up for a trip.
- I use 30A 240V at work for 2-4 hours daily which covers commuter distance.
- I rarely supercharge unless on longer trip.
- not had a power blip or outage at home in the last 16 months.
- I usually run at 50% or below unless long trip needed which is <twice a year.

So my situation with charging is extremely unique. My job requires me to move every 2 or 3 years so I built what I call a solar cart that utilizes 8x victron energy 5000va (4000 watt) inverters (ul1741 listed), 30kwh lifepo4 at 48vdc storage, and max of 350 amps of solar input (currently only have about 40 amps worth of solar set up). I set up 2x of the victron inverters to take in 120vac or 240vac and covert it to 48vdc. The other 6 inverters are set up to output 240vac with ~100 amps that powers a panel where i have a wall charger mounted and a nema 14-50 plug. I mounted the entire system on a 1 ton rated hand cart so I can move my stuff when I move and then gets put on blocks in the garage. Needless to say, the victron inverters put out power cleaner than anything you could hope to see from the grid, voltage stays between 119.8 and 120.2 on each phase and frequency stays 59.9 to 60.1 hz.

So if the truck is in the garage it charges oft the wall charger, outside it connects to the nema 14-50 outlet. My charge limit is usually 80% and charge rate i set at 20 amps unless i need a faster charge rate.

Supercharger and deep discharges are only done on long distance trips, so like I can count on one hand those trips I take per year, so maybe like 50-100 charging stops at a supercharger per year.

Edit:spelling

Sponsored

 

[Sousray]

Does anyone know the % failed on these over all . I bought my CT dual motor in Nov 2024 . VIN 36xxx. I have not had any issues, but approaching 40K now. Should I be worried? I take several long cross country trips a year.

 

[Edphonse]

Same. I presume you are using mobile?

Yes I only browse this forum on my phone haha

 

[Edphonse]

Does anyone know the % failed on these over all . I bought my CT dual motor in Nov 2024 . VIN 36xxx. I have not had any issues, but approaching 40K now. Should I be worried? I take several long cross country trips a year.

My vin is 30xxx iirc, so you likely have the first or 2nd PCS that I have had. Bought my truck first week of sept 2024 and the new pcs was installed in Dec 2024. The first one, when it faulted, if you shutdown the truck and let it sleep for 30 min, it would reset the fault flag and you could keep going. My fault came in at 500 miles of ownership on a cross country trip. Reset the trip as described, drove another 4kish miles until the fault came back in (on the way back from the cross country trip), reset it again and it stayed cleared until tesla replaced it.

 

[Sousray]

My vin is 30xxx iirc, so you likely have the first or 2nd PCS that I have had. Bought my truck first week of sept 2024 and the new pcs was installed in Dec 2024. The first one, when it faulted, if you shutdown the truck and let it sleep for 30 min, it would reset the fault flag and you could keep going. My fault came in at 500 miles of ownership on a cross country trip. Reset the trip as described, drove another 4kish miles until the fault came back in (on the way back from the cross country trip), reset it again and it stayed cleared until tesla replaced it.

So your reset is the complete power shut down? or the double button one? Worried since I am about to take a 200K trip

 

[Edphonse]

So your reset is the complete power shut down? or the double button one? Worried since I am about to take a 200K trip

It was ensure all standby features are disabled, such as ac outlets, usb outlets, sentry mode, etc, hit the power off button in the menu, get out of the vehicle and dont touch it or the app for 30 min.

 

[hbutler]

All of a sudden, my truck will no longer charge at 48amps at home but will only get to 24. Is that a sign of a pcs failure coming? I noticed it after the latest software update(not completely sure if first time it happened was after the software update). Think Tesla may have dialed it back

 

[UberNoob]

All of a sudden, my truck will no longer charge at 48amps at home but will only get to 24. Is that a sign of a pcs failure coming? I noticed it after the latest software update(not completely sure if first time it happened was after the software update). Think Tesla may have dialed it back

Sure is your sign, look on service mode for PCs alerts, make a service appointment and they will remote diagnose it.

 

[Shaney84]

Mine went out a week ago. Purchased in December '24, VIN 55k. They haven't given me an estimate yet on repair timeline.

 

[HaulingAss]

It could also be the home charger themselves - which may not regulate the AC signal well at 48 amps- causing the PCS to take the brunt of noise/spikes. As these are already in a vast installed base - they may limited in what solution they can take.

This is nonsense. The Wall Connector does zero regulation of the grid power, it connects the vehicle to whatever circuit it's powered by.

 

[Flynn]

What MOSFETs Are and Their Role in the PCS

A MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) is essentially a high-speed electronic switch. In power electronics, they’re the workhorses — they switch on and off thousands of times per second to control and convert electrical energy. Think of them like relay switches but operating at frequencies no mechanical part could ever match.

The CT’s PCS2 functions as both the onboard charger (OBC) and DC-DC converter in a single unit. Its core job is to take the ~800V from the main pack and step it down to a stable 48V to run all the truck’s accessories, control modules, lighting, steer-by-wire, etc. It also handles bidirectional power — so V2L, V2H, and external outlet functionality all run through it. 

The MOSFETs inside are the actual switching elements doing that voltage conversion. Every charging session, they’re toggling millions of times, generating heat with each cycle. The thermal stress from that repeated expansion and contraction is where the problem lives.

At 48A, the MOSFETs are pushed to temperatures where their physical structure can begin to micro-fracture or “delaminate” over hundreds of heat cycles. At 24A, the thermal expansion/contraction of the internal boards is significantly reduced. 

The widespread PCS failures in 2024 and 2025 Cybertrucks are attributed to thermal fatigue in the MOSFETs — and this was not a PCS-isolated problem. The drive inverter recall (NHTSA 24V-832) used similar faulty MOSFET components from the same production era.  So the root issue is that the MOSFET spec chosen for the original PCS wasn’t robust enough for the sustained thermal cycling demands of the CT’s 48V architecture under real-world charging loads.

The PCS is also not as vertically integrated as some Tesla components, so sourcing, qualifying, and scaling production of revised boards involves suppliers, reliability testing, and certification — it’s not a quick ramp like simpler parts.

Sponsored