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Power reduced may be restored on vehicle restart BMS errors w094 and u008?

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sorka

Well-Known Member
Feb 28, 2015
11,718
9,687
Merced, CA
Has anyone had these two BMS errors before? I've been getting them intermittently ever since my MCU2 upgrade. The first time Tesla said it was an incorrect HVL node configuration in the MCU. They charged me for that without realizing they'd just upgraded my MCU the week before.

But the errors persisted. When they happen they happen for hours and power is reduced to something barely faster than my prius and regen is disabled.

It's at Tesla now. They say they can't figure it out and want me to authorize two more hours of labor to try and find the issue. I've read in the past these errors related to the contactors but now can't find those posts.

I'm tempted just to take the car back until it either fails and leaves me needing a tow or the errors come back without ever going away before I bring it back to Tesla to diagnose.
 
What's not possible.

Yes indeed the P85D could be upgraded (in the past by Tesla) to L. L could also be turned on in software without the hardware modifications, and this is what I was alluding to, but this would be unethical and dangerous. If one had the part numbers he could conceivably do the hardware upgrade, but again unethical, and I know this is not the path you've taken.
 
What's not possible.

Yes indeed the P85D could be upgraded (in the past by Tesla) to L. L could also be turned on in software without the hardware modifications, and this is what I was alluding to, but this would be unethical and dangerous. If one had the part numbers he could conceivably do the hardware upgrade, but again unethical, and I know this is not the path you've taken.

Nobody has ever reported that happening on a P85DL. P90Ds all came with the hardware from the factory so in those cases it's possible to hack the upgrade via software. Even if this did happen, and tesla turned off and then some one hacked it back on, it's still irrelevant to this thread as all the existing hardware was present.

Remember, you said "Unless you had someone turn on L without the proper and ethical hardware modifications.", which contradicts your second message about turning it on after Tesla disables it because it would already have the proper hardware modifications. You can't have it both ways.

And none of this is related to the topic of the thread in anyway.
 
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Picked up the car today. They were unable to reproduce the errors. They can see them all in the logs. They said they know there's a CANBUS communication problem but just couldn't track it down without the issue actually happening at the time.

The only charged an hour of labor and said to use the service app to text when the issue happens again. My service advisor, who has always been awesome, said that any thing I text in that text will go to her directly and she'll have someone jump on it as soon as it starts happening.

Crossing my fingers. We're going to Disneyland on the 7th and 8th and I'm really hoping it doesn't strand me.

I just drove the hours home and the issue did not come back on this drive.
 
Just wanted to update this thread. I figured out the problem several months ago but wanted enough time to go by to be sure.

The errors only happen when I drive with the Elm327 canbus dongle attached. I used to drive with it continually for years without any issues. It appears with MCU2 this is no longer the case and it's somehow every now and then messing with the comms on the bus.

Around June I suspected it might be related so I unplugged it and the errors never came back. Then one day several months ago I plugged it in and forgot to remove it and the same errors came back and power was reduced. I remembered I'd forgotten to unplug the dongle and did so while driving and the error state cleared immediately. Since doing the MCU2 update in March, the errors have only ever occurred with the scanner plugged in.

So FYI in case anyone else sees the same thing and doesn't realize the cause.
 
Hi,
Got this problem where the car wasnt able to be driven. Got it towed away to the nearest tesla vehicle center where they been trying to figure out the problem for two weeks straight now. Only thing they said is that its a can bus failure but they dont know from what or where. Suspecting a damaged cable or something.
My problem started a wednesday when i charged the car at a hotels parking with my tesla cable connected to their 220V wall socket.
All good when i went to sleep. Woke up the morning after and went to work. 1h later at 7:30 am at office i got a notification to my phone that my charging was cancelled. Didnt think about it much more as I was planning on having breakfast at 9am.
Came back to the hotel and saw that someone had unplugged my cable from the wall and left it on my tire while the other side of the cable was still in my cars charging port.
Plugged the car back to charging and didnt notice anything strange. 3h later i was on my way to a meeting but couldnt drive. Got all these failure messages on my infotainment system. A turtle popped up with power reduced and emergency brake inactive, auto steering inactive, and so on.
Had to tow it away to get it fixed as the tesla support couldnt help with restarting it. Total reeboot two times and one smaller didnt fix it. The car was having all things working as such things as stereo, climate, lights and all. But it just didnt wanna get the shiftgear to drive and drive away.

Anyone had this issue and now what it is?
 
Hi,
Got this problem where the car wasnt able to be driven. Got it towed away to the nearest tesla vehicle center where they been trying to figure out the problem for two weeks straight now. Only thing they said is that its a can bus failure but they dont know from what or where. Suspecting a damaged cable or something.
My problem started a wednesday when i charged the car at a hotels parking with my tesla cable connected to their 220V wall socket.
All good when i went to sleep. Woke up the morning after and went to work. 1h later at 7:30 am at office i got a notification to my phone that my charging was cancelled. Didnt think about it much more as I was planning on having breakfast at 9am.
Came back to the hotel and saw that someone had unplugged my cable from the wall and left it on my tire while the other side of the cable was still in my cars charging port.
Plugged the car back to charging and didnt notice anything strange. 3h later i was on my way to a meeting but couldnt drive. Got all these failure messages on my infotainment system. A turtle popped up with power reduced and emergency brake inactive, auto steering inactive, and so on.
Had to tow it away to get it fixed as the tesla support couldnt help with restarting it. Total reeboot two times and one smaller didnt fix it. The car was having all things working as such things as stereo, climate, lights and all. But it just didnt wanna get the shiftgear to drive and drive away.

Anyone had this issue and now what it is?
Is this still going on or did they fixed te problem?
 
Hi,
Got this problem where the car wasnt able to be driven. Got it towed away to the nearest tesla vehicle center where they been trying to figure out the problem for two weeks straight now. Only thing they said is that its a can bus failure but they dont know from what or where. Suspecting a damaged cable or something.
My problem started a wednesday when i charged the car at a hotels parking with my tesla cable connected to their 220V wall socket.
All good when i went to sleep. Woke up the morning after and went to work. 1h later at 7:30 am at office i got a notification to my phone that my charging was cancelled. Didnt think about it much more as I was planning on having breakfast at 9am.
Came back to the hotel and saw that someone had unplugged my cable from the wall and left it on my tire while the other side of the cable was still in my cars charging port.
Plugged the car back to charging and didnt notice anything strange. 3h later i was on my way to a meeting but couldnt drive. Got all these failure messages on my infotainment system. A turtle popped up with power reduced and emergency brake inactive, auto steering inactive, and so on.
Had to tow it away to get it fixed as the tesla support couldnt help with restarting it. Total reeboot two times and one smaller didnt fix it. The car was having all things working as such things as stereo, climate, lights and all. But it just didnt wanna get the shiftgear to drive and drive away.

Anyone had this issue and now what it is?
I also have this same issue, car has been sitting for months now since I can't figure out how to fix it. Are you still active on this forum or does anyone else have this issue or could help in any way?