PCS failure rates by year...is it just a matter of time?

[Cybertruck 1974]

Mine failed at 60k fwiw

Don't tell me that!! Mine was replaced also Sept 25. Figured they fixed that problem as they used an updated PCS for rear and front motors. Both of mine were replaced at that time. Mine blew it's over voltage fuse links at high power side. Tech told me it's similar or same as airbag explosive devices on the fuse links. I didn't hear anything just got the warning on screen. So you had it happen again? That's not making me feel good as I'm at 60k right now.

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[Macgyverfever]

Don't tell me that!! Mine was replaced also Sept 25. Figured they fixed that problem as they used an updated PCS for rear and front motors. Both of mine were replaced at that time. Mine blew it's over voltage fuse links at high power side. Tech told me it's similar or same as airbag explosive devices on the fuse links. I didn't hear anything just got the warning on screen. So you had it happen again? That's not making me feel good as I'm at 60k right now.

Nono just saying it happened to me at 60k lol if I had 2 xanax brother I'd share

 

[koolio]

I’d imagine how fast petite experience this failure is related to how often and how fast they charge (?).

For me, I don’t charge too often at home, and when I do it’s at 11.5kw or a trickle charge from ‘charge on solar’. So I wonder if my truck were to be impacted, I’d be Much longer than others in this thread.

 

[OldDirtyRobot]

you're late. FSD transfer is no longer allowed.

If he already started the process and its for a premium AWD, probably not.

 

[EXPTREVER]

If he already started the process and its for a premium AWD, probably not.

I’m gonna keep my truck now that they are swapping my PCS next week. Also I found out for FSD transfer I would have to take delivery by March 31st which wouldn’t happen. And foundation series cybertrucks are excluded. But I’m good now so moot point. I appreciate all the discussion here as it helped me a lot.

 

[FL370]

Data point. FS series Feb 24 delivery with 30k. Scheduled a service due to vibrations/ flapping sounds coming from the roof. They automatically added PCSgen2 to the order. That morning the truck would only AC charge at 24 Amps. Like it knew something was wrong .

 

[EXPTREVER]

Data point. FS series Feb 24 delivery with 30k. Scheduled a service due to vibrations/ flapping sounds coming from the roof. They automatically added PCSgen2 to the order. That morning the truck would only AC charge at 24 Amps. Like it knew something was wrong .

Let me know what comes from the vibrations/flapping noise. I have the same noise that sounds above me. Service center visit scheduled for next week.

 

[FL370]

Let me know what comes from the vibrations/flapping noise. I have the same noise that sounds above me. Service center visit scheduled for next week.

Will do. Does the sound sound like something is slapping against the roof, like a loose strap? In my case or only happens after I park it outside, then drive at highway speeds..it lasts for a minutes, then goes away.

Grok suggestes bad seals around the roof panel..

 

[EXPTREVER]

Will do. Does the sound sound like something is slapping against the roof, like a loose strap? In my case or only happens after I park it outside, then drive at highway speeds..it lasts for a minutes, then goes away.

Grok suggestes bad seals around the roof panel..

Oh interesting, no I think our issues are different. Mine happens specifically between 30-40 miles per hour and sounds like a loud buzzing/clicking noise above my head. But when sitting in the backseat it sounds like it's coming from outside. I can't seem to pinpoint it so hoping the service tech knows it from experience.

 

[mongo]

It would certainly run cooler with two at half power (more components to dissipate heat) but power electronics are designed to run at 100% of design capacity without thermal problems.

As to efficiency, one module running at 100% would likely be more efficient than two modules running at 50%, if the power efficiency curves follow the curves of inverters I've investigated.

Agree, 100% should not be an issue.

Inverter efficiency curves often look the way you state due to ratio of converted power vs power consumption of just being on, but the conversion itself should be more lossy at higher power, unless it's a tuned ZCS/ZVS setup which these might be.

Double the current is 4x the resistive losses. Two stages is 2x the resistive loss plus the energy required to run the module.

 

[Gigahorse]

If the problem is a manufacturing mistake, such installing a 4 ohm resistor instead of 8 ohm, then they’re all gonna fail eventually.

But if the issue is a component made with poor quality control, then some percentage will fail, not necessarily all.

Yea that is the mystery a lot of early VIN people are dealing with.
It seems like a very high % have had an issue and are the others just lucky and not going to have to deal with it, or just have not had it break yet.

 

[CyberGus]

Yea that is the mystery a lot of early VIN people are dealing with.
It seems like a very high % have had an issue and are the others just lucky and not going to have to deal with it, or just have not had it break yet.

Years ago there was an issue with Macbooks overheating. The issue ended up being poor training of the workers, who were applying thermal paste to CPU in globs instead of the correct paper-thin layer.

Perhaps something similar happened with the PCS? The components should be rated for X hours at Y degrees, with the full understanding that exceeding the rated temperature will reduce the lifespan. The cooling is designed with that in mind, so either the engineers did not sufficiently account for the heat, or the components have a abnormally high failure rate.

As usual, I am 100% positive that I am entirely speculating.

 

[Gigahorse]

Years ago there was an issue with Macbooks overheating. The issue ended up being poor training of the workers, who were applying thermal paste to CPU in globs instead of the correct paper-thin layer.

Perhaps something similar happened with the PCS? The components should be rated for X hours at Y degrees, with the full understanding that exceeding the rated temperature will reduce the lifespan. The cooling is designed with that in mind, so either the engineers did not sufficiently account for the heat, or the components have a abnormally high failure rate.

As usual, I am 100% positive that I am entirely speculating.

Excellent reference to the toasty Macbooks.
Based on Tesla's engineering team my $ would be on incorrect installs, we have seen it already with soap on accelerator pedals etc.

 

[MCraft99]

Will do. Does the sound sound like something is slapping against the roof, like a loose strap? In my case or only happens after I park it outside, then drive at highway speeds..it lasts for a minutes, then goes away.

Grok suggestes bad seals around the roof panel..

That's what my CB sounds like. Do you have the factory lightbar installed as well?

 

[FL370]

That's what my CB sounds like. Do you have the factory lightbar installed as well?

No lightbar. Still in service. The technician still have no idea what causes it.

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