(PCS) Failure

[Maddmax]

Truck wouldn't charge beyond 24A, after a few days got a 2 active alerts. Took it in for service today and they said it's a known issue happening to a lot of trucks, so much so they have put out a bulletin.

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[dalton108]

Put out a bulletin to whom? Where?

 

[EWELON]

this is one of the most active topics in the forum right now. find one of the bigger threads and post your info there for people to see. your VIN would be the most useful along with your charging habits.

 

[CyberGus]

Truck wouldn't charge beyond 24A

 

[EWELON]

I would def buy this sticker

 

[seussiii]

I feel like at this point we need a "my OG PCS survived" sticker.

 

[mongo]

I feel like at this point we need a "my OG PCS survived" sticker.

Which culminates in
"Turn in your OG PCS card"

 

[Mini2nut]

The big question: Have Tesla engineers discovered the root cause of failure and updated this $1700 part?

 

[Eka]

The big question: Have Tesla engineers discovered the root cause of failure and updated this $1700 part?

I think it is a soldering issue. The power FETs are pick-n-placed and soldered on the bottom of the PCB first, then the top side parts are pick-n-placed and soldered. During that top side soldering, the bottom side FETs' solder melts and they no longer sit flat. The FET's documents even said they needed to be soldered last.

 

[mongo]

I think it is a soldering issue. The power FETs are pick-n-placed and soldered on the bottom of the PCB first, then the top side parts are pick-n-placed and soldered. During that top side soldering, the bottom side FETs' solder melts and they no longer sit flat. The FET's documents even said they needed to be soldered last.

Or the "top" went through first with the large parts glued down and the FET side was done last.

Seems like if they did ignore TN1378, there would be more obvious effects than just a little vertical sag/ misalignment.

 

[Eka]

Or the "top" went through first with the large parts glued down and the FET side was done last.

Seems like if they did ignore TN1378, there would be more obvious effects than just a little vertical sag/ misalignment.

The remelting of the solder and hanging there suspended by the solder helps improve centering of the part.

I'd need to see a current board to know what they are now doing. The board Monro had definitely had FETs that were not parallel with the PCB. The impressions they made in the heat transfer goop looked like the FETs were off angle like the bottom side FETs for a board I designed. When we moved all the FETs to one side and soldered it last, it fixed the thermal problem. Thin supports during soldering can also be used to keep the parts level.

 

[wb9vxy]

Truck wouldn't charge beyond 24A, after a few days got a 2 active alerts. Took it in for service today and they said it's a known issue happening to a lot of trucks, so much so they have put out a bulletin.

 

[wb9vxy]

I just went down to 24A charging on my CT.

I have a couple of road trips coming up.

Does the AC failure portend 48V converter failures and a bricked truck or or folks
seeing that the 48V portion of the PCS2 continues to home along?

Tnx

T3

 

[mongo]

I just went down to 24A charging on my CT.

I have a couple of road trips coming up.

Does the AC failure portend 48V converter failures and a bricked truck or or folks
seeing that the 48V portion of the PCS2 continues to home along?

Tnx

T3

Charging (DCAC) failures seem to be independent from 48V (DCDC) failures.

 

[mongo]

The remelting of the solder and hanging there suspended by the solder helps improve centering of the part.

I'd need to see a current board to know what they are now doing. The board Monro had definitely had FETs that were not parallel with the PCB. The impressions they made in the heat transfer goop looked like the FETs were off angle like the bottom side FETs for a board I designed. When we moved all the FETs to one side and soldered it last, it fixed the thermal problem. Thin supports during soldering can also be used to keep the parts level.

What looks like height variation may have been where the pink detached from the insulator rather than the fets. Per a contact, it takes some effort to de-pink the PCB after separation.

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