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Replaced 12V battery, now screen won't fully reboot

Replaced 12V battery, now screen won't fully reboot

I Replaced 12V battery, now screen won't fully reboot despite me resetting both the instrument cluster and the screen via the steering wheel bottons/scrolls. Any ideas?

ST70 | 7 mai 2019

YOU replaced it or Tesla?

motaskate | 7 mai 2019

I replaced it, with the same C&D AGM battery.

Captain_Zap | 7 mai 2019

My understanding is that similar batteries are not the same. I would think that Tesla would have a system in place to tell the car that there is a new battery that they are monitoring.

sr.smr | 7 mai 2019

If you have not already done so, perform all three reboot procedures. Check the fuses in case one opened as a result of introducing a spike when reconnecting power from the battery.

Tropopause | 7 mai 2019

Is the car driveable with the touchscreen inop?

kerryglittle | 8 mai 2019

Is it possible your replacement battery is not compatible with Tesla? It has to be a deep cycle marine battery I believe. I would rather Tesla SC work on my car than myself or anyone else. Then at least you have peace of mind and can blame them if something goes wrong. After paying $140,000.00 for my car I'm not about to try and save a few bucks by cheaping out and let the professionals do their job.

Bill_75D | 8 mai 2019

@kerry - Yeah, but those are Canadian dollars ;-)

pbtarget | 8 mai 2019

We had the battery replaced in our 2015 Type S under warranty.
The tech had to use the laptop to reset the system.
They have had 3 different batteries and the new one may not be a "plug and play" install.

I'm a tech ( boats) and watched him do the replacement. There was more involved that just disconnecting the Pos & Neg cables and dropping in a new batt.

kerryglittle | 8 mai 2019

Yeah Bill I know our lame duck is in the crapper. LOL. Todays conversion is $103,950.876 American greenbacks. Now I know why the biggest portion of my investments is in the US. Ha ha.

motaskate | 8 mai 2019

UPDATE: Last night my car would not charge and so I desperately showed up to TESLA today and asked them to at least get it to charge... which thankfully they did. Here is what we figured out.
I have had a "Low vehicle coolant" warning on for some time for which I had an appointment to fix, in addition to a defective tail light. I originally called to make this appointment and no one called me back. I called again and scheduled the earliest appointment for end of May. Between then and now in that time the 12V battery was reading low voltage, for which the car began shutting down various systems but it was still chargeable/driveable. According to TESLA the car is not capable of displaying two warnings at the same time so it prioritized the vehicle coolant, and meanwhile my 12V degraded further and further until it caused the screen to start continuously rebooting until the MCU failed. I finally noticed glimpses of the 12V warning before it was immeditaely replaced with the coolant warning and so I replaced the 12V battery myself but the damage was done. The MCU continued to erroneously boot the screen repeatedly until it died last night and interrupted my charging. Im thinking it is possible that the initial contact when i put the battery leads back on could have spiked voltage but a fuse should have caught that, however the tech is saying it is most likely the continuous rebooting which i couldnt stop. In addition, the tech is stating the electric motor is making a funny low pitched "wonky" sound and its on its last leg. They stated they will cover that, but to expect at least $2200 for the screen. Needless to say im displeased that a $75000 car had the screen/mcu/tailight/both airbags/charge controlled(charge controller i replaced within 12 months of car purchase, it was defective) and now the drivetrain all fail after 3.5 years. I received my car Dec 2015. Ridiculous....

rxlawdude | 8 mai 2019

You know what they say about a doctor who treats themselves, or a lawyer who represents themselves?

More to the point, unless you can point to where Tesla states 12V battery replacement can be done by an owner, I'm afraid it's clear by doing so you broke it, and you own the problem. Ridiculous you blame Tesla for that.

rxlawdude | 8 mai 2019

(And yes, my first sentence was atrocious English.)

motaskate | 8 mai 2019

Please read correctly, specifically the part where I said "the damage was done." The 2 MCU failure codes were produced prior to replacing the 12V battery. The tech showed me on his laptop. Stated it was dead weeks ago. I replaced battery yesterday. I'm not taking ownership of anything.

motaskate | 8 mai 2019

BTW I didn't blame anyone so please read before you mouth off. Just displeased with this situation. The techs and staff there were extremely professional and great.

sr.smr | 8 mai 2019

@motaskate, doesn't the car come with a 4-year new car warranty? Why would the MCU failure be on your dime? You already set up the service visit for the coolant and you proactively replaced the battery since you could not get service until late May. Had the circumstances changed and you were given a sooner appointment, all would be repaired by Tesla and maybe you would be only charged for the battery replacement. I too agree techs and staff are great, but I would speak to the service manager and maybe he could reduce the cost or even waive the fee in consideration of the circumstances.

I learned from your experience not to perform any repairs myself, but rather contact Tesla and escalate the urgency of the repair. They could have arranged to send out a rover.

motaskate | 9 mai 2019

The MCU is my responsibility because my commute to work is long the last 3.5 years and my car has 98,000 miles. I wasn't going to repair anything except for the emerging circumstance as you said. In my experience companies always try and blame it on you one way or another. They'll probably frame it like I shorted it out and not even talk to their tech but I'll push back and we'll see.

Anyways I just wanted the information out there in case it happens to someone else. Please also note that whatever your settings are at the time the MCU dies that's where you are stuck for most important things. Some things can me modified by the app, however somethings cannot like the charge limit and your scheduled charging. Currently at home I now have to set my alarm to midnight every night and start charging from my mobile app because car's last setting was to not allow charging till midnight. Also my charge limit was set to 60% and I cannot change that now because the MCU also processes certain commands from the mobile app as well. It will not adjust charging limit. I've also had issues getting the charge port open without the OEM charging cable. Obviously radio, A/C & heater, and bluetooth are out.

If anyone has suggestions on how to fix charging schedule/limit I'm all ears...

murphyS90D | 9 mai 2019

The scheduler in VisibleTesla has entries to start and stop charging. I've never used it and VisibleTesla is no longer able to wake a sleeping car so it may not be of much use. There is no longer anyone supporting VisibleTesla. It also has the ability to change the car's target charge level. I don't know if VisibleTesla can do anything without a working MCU.

sr.smr | 9 mai 2019

I did not realize your car has high mileage and therefore out of warranty. Then it is just worth it to let Tesla complete all necessary repairs. At least you'll have peace of mind that every repair is done properly and guaranteed by Tesla. I'm of the opinion not to own a car too far out of warranty. After owning many cars, I always had the rotten luck of having one failure happen after the next right after that magic warranty period. And repairs are not cheap. Might as well sell it and buy a nice new reliable car under warranty with all the newest bells and whistles. This is my first Tesla, so maybe it is the exception, but I'm not a betting man.

p.c.mcavoy | 19 mai 2019

@motaskate - Question regarding your comment

"According to TESLA the car is not capable of displaying two warnings at the same time ..."

I agree that I've only observed one warning on the cluster behind the steering wheel. There will also be an alert icon, looks like an exclamation point ! that will be displayed at the top center of the main screen. Did you ever touch that during this period? I believe it will display a list with multiple messages at one time. The one situation I had like that there were multiple messages (about 4 if I recall correctly) all displayed at the same time.

Silver2K | 19 mai 2019

"According to TESLA the car is not capable of displaying two warnings at the same time ..."

This does not mean multiple messages will not show on your screen, it means they won't all pop up at once.

If you have multiple issues, the messages will pop up one after the other before your car in the cluster

Silver2K | 19 mai 2019

Before/ behind

AERODYNE | 19 mai 2019

I think for folks like the OP who drive a lot or keep the cars well out of warranty, there is no reason to not do maintenance yourself if you can. Battery replacement is one thing we know has to be done

With the Tesla workforce stretched thin, I want to keep my car away from them if possible. Rangers are better, because you can keep an eye on them, and the car stays in your possession.

There are a few things you can do to prevent a power spike, like powering off and connecting a small SLA batt to the terminals in the front, before replacing the main batt.