A growing number of Tesla Cybertruck owners are losing the ability to charge at home due to failures of the truck’s Power Conversion System (PCS), the unit that handles AC charging and steps the high-voltage pack down to the 48-volt system.
Tesla is aware of the problem and is quietly replacing the part case-by-case, but it has not issued a recall, and owners are waiting weeks for replacement units they can’t source.
What’s failing, and how owners find out
The PCS combines the Cybertruck’s onboard charger and DC-DC converter into a single unit. When it fails, the truck loses Level 2 AC charging, the cheap overnight home charging that is one of the biggest advantages of owning an EV.
Owners across the Cybertruck Owners Club and Tesla Motors Club forums describe a consistent pattern. Home charging first drops from 48 amps to 24 amps, then stops entirely within days. The truck throws an “AC Charging Unavailable” warning and logs service-mode codes like PCS2_a094_acChargingUnavailable, PCS2_a137, and PCS2_a136_cycloAMosfetHealthCheckFailed, the last of which points to a failed MOSFET health check inside the converter.
In most cases the truck still drives and can still DC fast charge at Superchargers, though some owners report the truck dropping into a speed-limited Service Mode.
Mileage doesn’t appear to be the trigger. Forum members have posted failures at 11,994 miles, 16,677 miles, and 31,250 miles, with others reporting failures under 10,000 miles. Some trucks have failed a second time after a full PCS replacement.
How widespread is it?
There is no official failure rate, because only Tesla has that data. But the owner-run poll on the Cybertruck Owners Club is the closest thing to a public tally.
As of this week, 223 owners had voted: 91 (40.8%) said their PCS failed and was replaced under warranty, 15 (6.7%) suspected a failure pending confirmation, and only 2 (0.9%) had paid out of pocket. The remaining 116 (52%) reported no issue.
That is a self-selected poll in a thread specifically about PCS failures, so it over-represents the problem. It is not a reliable failure rate. But nearly 100 confirmed replacements from a single forum is a real signal, and separate active threads are tracking new failures weekly.
Some Cybertruck owners having the issue were told by Tesla service advisors that the majority of Cybertrucks have the problematic PCS, but it doesn’t mean that they will fail.
The fix is a revised PCS (owners have tracked hardware revisions E, F, and now G, part number 1777777-T2-G) along with a new wiring harness. It is not a quick swap: technicians have to remove the tonneau cover, the bed floor, and parts of the air suspension to reach the unit. Trucks with the Terrestrial Armor underbody package add roughly eight hours of labor on top.
This isn’t Tesla’s first power-electronics problem on the Cybertruck. In late 2024, Tesla recalled over 2,000 Cybertrucks to replace inverters that could cause a loss of power, also a MOSFET issue.
The $1,000 tell
Here’s the part that matters most.
For trucks still under Tesla’s basic 4-year/50,000-mile warranty, the PCS replacement is free. For owners out of warranty, the repair reportedly ran $5,000 to $7,200 in parts and labor. Tesla has since dropped that out-of-warranty price to roughly $1,000 as a “goodwill” gesture.
You don’t offer to eat 80% of a repair bill on a part you believe the customer wore out. Charging a token $1,000 for a multi-thousand-dollar repair is a de facto admission that this is a manufacturing defect, not normal wear. And if it’s a defect, the honest move isn’t a discount, it’s replacing the failing units across the fleet for free, or issuing a recall.
The warranty situation makes the double standard sharper. Early 2024 and 2025 Foundation Series trucks, the ones most exposed to this, only carry the basic 50,000-mile coverage, and Tesla doesn’t offer an Extended Service Agreement for the Cybertruck. Meanwhile, Tesla quietly added a new 7-year/70,000-mile propulsion warranty for 2026 Cybertrucks that explicitly covers the PCS. It is not retroactive.
Compare that to how another automaker handled a nearly identical problem. When Hyundai and Kia had widespread failures of their ICCU, the analogous power-conversion component, they extended warranties for affected cars. Tesla is doing the opposite: covering newer trucks going forward while leaving early adopters exposed.
Weeks without home charging
Even when the repair is free, the wait isn’t painless.
Owners report replacement PCS units on national backorder, with service appointments and parts pushed out by weeks. Forum members have posted lead times of “14 days until next available appointment,” pickup dates slipping repeatedly, and one owner on X marking “week 8” still waiting. Another described being unable to AC charge with no Supercharger conveniently nearby.
To bridge the gap, Tesla pushed a firmware update that keeps Supercharging enabled on affected trucks even when AC charging is down, and it’s covering Supercharging costs for affected owners until their trucks are fixed. It’s a reasonable stopgap, and multiple owners have confirmed receiving it.
But relying on DC fast charging for daily driving for two months is exactly the ownership experience EVs are supposed to eliminate. As one Cybertruck owner put it on X, a PCS failure “would be equivalent of someone putting a locking gas cap that can’t be removed on a gas vehicle. When you run out, you’re done.”
Author: Fred Lambert
Source: Electrek
Reviewed By: Editorial Team
