PEM Failure

[tdevince]

Last week, my PEM decided to give up the ghost as I was driving down the highway. I got a "Powertrain Fault" which shut down power, and I coasted to the shoulder. I tried shutting down the car and restarting. The fault was gone until I let off the brake and touched the accelerator in which case the fault came back. Called Roadside assistance and they towed me home. I uploaded loaded logs to Tesla, and the next day they arranged to send out a Ranger to my home on the following day (he had a 6.5 hr drive from Chicago to get to me).

When he got here, he checked the battery, motor, motor leads before condemning the PEM. So he changed out the PEM with a replacement and everything was good to go again. He checked the cooling fans and they seemed to be OK, though he did blow a lot of dust out of the back end of the car (I live on a gravel road, and have about 2/3 mile before I get to pavement). Looking at the PEM, its sealed where the leads enter and no dust was evident inside the connection area. The inverter portion receives cooling air from the fans, and while dusty didn't look too bad to me. I don't think dust caused the failure since the sensitive electronics are sealed. The cooling fan for the motor blows air into a duct that surrounds the motor, and thus never puts any air into the motor housing.

Overall, I'm very happy with the Roadside assistance and customer service from Tesla. I'm curious why my PEM failed, and am not sure if I'll get any feedback from Tesla on the cause of the failure.

[vfx]

Blowing out caked on dust is pretty normal. Brake dust is some of it.

So the law says when you take your car into a repair shop they have to show you the old parts they replaced in service. This is to help stop repair fraud. You can take the parts home if you want since you own them.

So can we keep our old Tesla Roadster parts?

[richkae]

Nobody has paid for new parts yet, the first significant crop of Roadsters to run out of warrantee will happen early next year.
Since its a warrantee replacement and you pay nothing, I doubt that law applies.

The first time someone replaces a PEM and has to pay for it, it will be a new question.
Since Tesla is going to be the only source of the parts, they could easily do something like selling the PEM for $10k and buy back the bad one for $5k.
Then you'd have to decide it was worth $5k to have the old PEM to play with.

[vfx]

Nobody has paid for new parts yet, the first significant crop of Roadsters to run out of warrantee will happen early next year.
Since its a warrantee replacement and you pay nothing, I doubt that law applies.

The first time someone replaces a PEM and has to pay for it, it will be a new question.
Since Tesla is going to be the only source of the parts, they could easily do something like selling the PEM for $10k and buy back the bad one for $5k.
Then you'd have to decide it was worth $5k to have the old PEM to play with.

I agree on all counts. But just for conversational purposes, what would be the point of the buyback though? Anyone trying to reverse engineer a part could just buy a car.

[bonnie1194]

I agree on all counts. But just for conversational purposes, what would be the point of the buyback though? Anyone trying to reverse engineer a part could just buy a car.

Quit applying common sense.

[bolosky]

I'm curious why my PEM failed, and am not sure if I'll get any feedback from Tesla on the cause of the failure.

I had a somewhat similar PEM failure. They told me that it was due to a small power supply in the PEM failing, and that a number of PEMs from the same vintage (I'm number 670) has similar problems due to inferior parts that went into the PEM. When I saw the failure, I got a large number of different error messages (of the form "Phase A low voltage"). I don't know if yours is due to the same problem, though.

[Tommy]

Since Tesla is going to be the only source of the parts, they could easily do something like selling the PEM for $10k and buy back the bad one for $5k.
Then you'd have to decide it was worth $5k to have the old PEM to play with.

I really hope Tesla only marginally marks up replacement parts. $5k for a PEM, that's equivalent to a transmission replacement; not exactly in keeping with the prevailing wisdom that EV's cost less to maintain. Early adopters might grudgingly accept higher priced replacement parts, however, the public at large won't transition to EVs if the cost of EV ownership doesn't compete with ICE.

[tdevince]

I had a somewhat similar PEM failure. They told me that it was due to a small power supply in the PEM failing, and that a number of PEMs from the same vintage (I'm number 670) has similar problems due to inferior parts that went into the PEM. When I saw the failure, I got a large number of different error messages (of the form "Phase A low voltage"). I don't know if yours is due to the same problem, though.

The only error message I got on the VDS is a Power Train Error. However, they said my log showed the PEM was throwing all kinds of faults (don't which ones). FYI, I'm number 1094, don't know if that would be the same batch of parts. I'd like to believe it was something like a bad part that gave up the ghost rather than some systemic problem that will reoccur.

[bolosky]

The only error message I got on the VDS is a Power Train Error. However, they said my log showed the PEM was throwing all kinds of faults (don't which ones).

The difference may be whether your VDS is set to display end user or debug messages. I have debug set, so I might be getting more detail.

[bonnie1194]

Baby Turtle is on the way to Menlo Park. "Powertrain problems". I was happily heading home from the office, thinking about an EV roadtrip to Oregon this weekend, when everything seized up and no more 'go' to be had.

I'll catch a flight on Sunday instead, it appears. I was looking forward to the drive.