Go to service notifications on the main page in service mode and check for messages. Look up the reference number. The message generated should have supporting information. BTW the Clarios battery is a Varta B32 I believe. Also in the Tesla app, you can ask a question by making a service request then in the text message put in what you have and what you have done. But first check for service notifications.
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"Proactive" 12v battery replacement - good idea or overkill?
- Thread starter joebruin77
- Start date
The two fault notifications are just that the battery is no good. I wonder if this in itself locks out the configuration change because a reboot might not be survivable. Will try and swap in a nice hot 13.6V battery to clear them tomorrow, otherwise I think I might need a remote diagnostic.
You don't need to replace the battery to clear the errors, just unpower the 12V system, which will clear them. Then try the battery selection before errors come back (which takes hours or days).
Unplug penthouse HV, unplug 12V, wait a minute, plug in 12V, plug in penthouse.
Try charge or test the new battery to make sure no faults. When a battery in installed the car initially stays awake for 6 hours chasing the new battery and testing. May be another issue. When the battery was changed did you completely depower the car? One needs to open the driver and RR passenger doors, close the Tesla app, turn off environmental, select power off from safety menu. Wait about 15 minutes for the relays to open (audible clunk sound) the footwell lights should be dark. Disconnect the negative terminal. Open the Right side of rear seat (see you tube) by moving the release lever, set the styrofoam to the side the rotate the gray lever down to Release the HV plug and set to side. then complete the swap (or reconnect in reverse order to do a full power off reboot. Once main HV battery and LV batteries are reconnected the car will again go through a 6 hour self check. If messages regenerated try one more time n service mode to change battery configuration from Atlas to Varta B32 (the Varta is also a 45AH 330 CCA) battery. That might align itself more closely to the Bosch you have. If you just swap battery while the car is still on (not discounting the HV battery, that will throw messages.
This is not the Official Tesla HV disconnect policy in the service manual. They only require 30 seconds and I fail to see why we wouldn't follow the service instructions:
stopcrazypp
Well-Known Member
30 seconds is only the climate shutdown time. The contactor time as pointed out probably is longer. That said, as you point out, the service manual doesn't require waiting for contactor to disconnect.This is not the Official Tesla HV disconnect policy in the service manual. They only require 30 seconds and I fail to see why we wouldn't follow the service instructions:
Wouldn’t disconnecting the battery and the connection on the penthouse kill the contactors immediately? No lower left to keep them closed. Should be similar to cutting the fireman loop and should isolate immediately.
Yes, it does exactly this, which is why you have to wait the 30 seconds to allow the HVAC to turn off, but that's it.
About a year and a half ago I responded to this thread saying that I proactively replaced my 12v in my M3 and had no regrets. Now I have a new MY that I took delivery of a month ago (although it is a '23.) Is there any change to this calculation? I presume I have the 15v battery now. Is the early warning system bullet proof now with that Lithium battery? Or is it the same situation as with my 2019 M3 where it could just die at any moment without warning?
I believe you have the order reversed. It should be: disconnect the 12v battery, disconnect the HV battery, reconnect HV, then 12v.
stopcrazypp
Well-Known Member
Yes it does, but I guess the thought on waiting the extra time is to ensure everything is shut down other than the vampire loads that the 12V battery powers. The manual however is only concerned about high power HV loads like the AC, not concerned if there is potentially a dirty shutdown of the computers or modules. Kind of like the difference between pulling the power plug on a computer while it is idle, versus putting it into sleep mode or hibernation mode before doing so.
stopcrazypp
Well-Known Member
My understanding is that the lithium LV battery is expected to last past the main battery warranty, so it shouldn't need proactive replacement, unlike the lead acid, which is a consumable.
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