Can I hard reboot without powering off the car?

[mkoenig214]

My screen is black and won't turn back on. I've tried rebooting by holding the scroll wheels and brake for 30 seconds. I've removed all USB devices.

I'm reading that it's possible to disconnect the 12V battery and the connector underneath the rear passenger seats, but all instructions say to turn off the car first. How can I do that if the screen won't turn on?

 

[ATPMSD]

Can you put the car in drive and will it move? If not you have a battery problem.

 

[mkoenig214]

I was able to last night, but not this morning. Was able to roll down a window as well

 

[ATPMSD]

I was able to last night, but not this morning. Was able to roll down a window as well

Almost certainly the battery. If the 12v battery is dead the car will not wake up. Try this:

Gain access to the 12v battery and use a jumper or another 12v battery to provide power. It has to be another battery or a jumper as a battery charger will not work. With power applied you should be able to wake up the car (just step on the accelerator). If the car wakes up, charge the car. If the car does not wake up the HV battery could be too low, or the 12v battery is dead. In this case you need to setup an appointment with Tesla.

If you are able to bring the car back, notice any error messages. The 12v battery may still need to be replaced.

 

[Graham J]

Almost certainly the battery. If the 12v battery is dead the car will not wake up. Try this:

Gain access to the 12v battery and use a jumper or another 12v battery to provide power. It has to be another battery or a jumper as a battery charger will not work. With power applied you should be able to wake up the car (just step on the accelerator). If the car wakes up, charge the car. If the car does not wake up the HV battery could be too low, or the 12v battery is dead. In this case you need to setup an appointment with Tesla.

If you are able to bring the car back, notice any error messages. The 12v battery may still need to be replaced.

Bookmarked, thanks. Just curious, why would a battery charger not work? I have a switchable 2A/10A one, I wonder if the higher setting would work.

 

[ATPMSD]

Bookmarked, thanks. Just curious, why would a battery charger not work? I have a switchable 2A/10A one, I wonder if the higher setting would work.

Can’t give you a creditable answer, but there are lots of posts that it does not work.

 

[mkoenig214]

Well, I was able to put the car into drive last night. I tried forcing the frunk open with a 12V source next to the tow hook, but it wouldn't trigger. I still had cabin lights on the inside, so I'm not sure what's going on

 

[ATPMSD]

Well, I was able to put the car into drive last night. I tried forcing the frunk open with a 12V source next to the tow hook, but it wouldn't trigger. I still had cabin lights on the inside, so I'm not sure what's going on

You cannot use the 12v source next to the tow hook to “jump” the car, you must connect the jumper directly to the battery. If you did that and it did not work, I suggest you setup a service call with Tesla.

 

[RayK]

Well, I was able to put the car into drive last night. I tried forcing the frunk open with a 12V source next to the tow hook, but it wouldn't trigger. I still had cabin lights on the inside, so I'm not sure what's going on

The 12V applied to the leads behind the tow hook cover is ONLY meant to open the frunk when the 12V battery is dead, thus gaining access to the 12V battery (after you remove the cowl cover). This method should NOT work if the 12V battery is good. If that's the case, then you should be able to open the frunk using the Tesla app (assuming that the main screen is still dead).

 

[mkoenig214]

Got the frunk open, 12v battery charge is still optimal. Unhooked both the 12v battery and the main wiring harness, let it sit for about an hour. No change. Will have it towed to the Tesla SC today

 

[mkoenig214]

MCU is dead, they are replacing it for $2k, since it's out of warranty

 

[Petermcg]

Ouch! Sorry to hear.