Dead battery model 3 Highland and manual override opening frunk does not work

[unknownuser20]

Last night I came home with 0% battery in my Tesla Model 3 Highland 2024. Since 5 hours the app says it cannot reach the car. The car is now locked. Trying to open it with the app or keycard does not work. I called Tesla and they told me I need to charge the 12v battery. They gave me instructions to open the front of the car by removing the plastic cover at the bottom of the bumper and connecting the cables to a battery. When I connect the cables to an external battery, I see sparks. I also measured the cables and there is a clear signal on them. However, the hood does not pop open. It is not a technical issue with the actuators because there is just no pop sound or anything coming from the front of the car.

What am I doing wrong?

I read in another topic that this method only works if the 12v battery is completely dead. If this is true, how can I drain the 12v completely if I can't open my car?

 

[Sophias_dad]

What kind of battery did you try to use during the opening attempt? You can get sparks from a too-small battery (lets say 9V battery) but it won't be enough to open the hood.

 

[unknownuser20]

I tried a booster from my friends garage and another car connected his 12v battery

 

[Tam]

Last night I came home with 0% battery in my Tesla Model 3 Highland 2024. Since 5 hours the app says it cannot reach the car. The car is now locked. Trying to open it with the app or keycard does not work. I called Tesla and they told me I need to charge the 12v battery. They gave me instructions to open the front of the car by removing the plastic cover at the bottom of the bumper and connecting the cables to a battery. When I connect the cables to an external battery, I see sparks. I also measured the cables and there is a clear signal on them. However, the hood does not pop open. It is not a technical issue with the actuators because there is just no pop sound or anything coming from the front of the car.

What am I doing wrong?

You are doing it right but the hard part is getting enough energy to wake up the car electronics.

It used to be easy with a small portable 12V battery but I am not sure with newer Tesla versions because they now use 15.5V Lithium battery. That means you might need a stronger source of energy.

I read in another topic that this method only works if the 12v battery is completely dead. If this is true, how can I drain the 12v completely if I can't open my car?

It looks like your 15.5V battery is completely dead. If yours not dead, you can still use its electronics like doors and the display screen...

 

[Cosmacelf]

Yeah you almost certainly have the new lithium ion 15.5V battery so a 12V boost might not work. Either find a 15v DC power supply or call for Tesla mobile service.