Please help! 2015 Model S won't wake up -- bad HV Battery? :S

[VifferFun]

Hey everyone!

Eek! I can't get my 2015 Model S P85DL to wake up today Here' s the sequence of events:

• Exhausted, I was about to leave work really late (11PM) and went into the Tesla app to turn on the cabin heat before walking to my car. I couldn't get the Tesla app to wake up the car. Odd, but these things happen.
• I walked up to my car but the door handles wouldn't autopresent. This is also odd, but I thought perhaps the car was in a deep sleep.
• I used the FOB and the doors unlocked without a problem.
• I get in the car but the screen won't turn on and the car won't wake up :S
  • I tried getting out the the car, locking it, and retrying multiple times to no avail
  • I tried to reboot the MCU by pressing both buttons and the brake for over 30 seconds, but it didn't respond to that at all
• Here are some additional diagnostics:
  • The headlights turn on
  • I'm able to roll the windows up/down
  • I can open the trunk and frunk
  • I can open/close all the doors without any problem
  • The interior lights work
  • I have a third-party dashcam (likely powered by 12V?) and it reboot itself a few times while I was sitting in the car trying to figure things out
  • In the app, it says "Last seen 12 horus ago", so it's definitely not waking up
  • More of an FYI, but I already upgraded from MCU1 to MCU2 about 2 years ago (after MCU1 failed)
• In the app, I can see that it sent two alerts about 10 hours before I left work (see image below):
  • hv-battery-replacement__alert_secondary
  • Drivability

I'm guessing that "hv-battery" refers to "high voltage battery", meaning the expensive battery pack rather than the 12V. I actually thought I was past the warranty on the battery pack, but I guess the good thing is that I still have warranty until August 2023 which makes me feel a bit better.

I eventually gave up on trying to wake the car and got my brother to pick me up. Now my beloved car is stranded in a parkade at work. I used the Tesla app to try and book a mobile service, but it's trying to get me to bring it in to the Service Centre in four days from now. I can't exactly get my car there when it won't wake up, and I can't leave my car in the parkade more than 48 hours :S I was hoping Tesla could send a mobile tech, but hopefully they can clear that up tomorrow.

If the car actually has to be towed to Tesla I don't even know how that would work. I can't put it into "tow mode" without the screen. And it's an AWD so I probably need a flatbed? But a flatbed tow truck probably can't even get into a parkade that has a somewhat low ceiling/clearance. I'm a little stressed out

To make matters worse, I'm in an important all-day meeting tomorrow in another city that I'll have to bum a ride to, but I won't be able to deal with my car while in the meeting. This really sucks!

Anyways, I'm just wondering if anyone has any ideas/thoughts/advice -- I'd appreciate anything I can get!

Thanks!!

 

[VifferFun]

The Tesla rep in the Tesla App chat jsut told me to tow my car to the Service Centre -- but didn't give any advice on how to applish that if I can't get into tow mode :S Any advice?

 

[AustinP]

To my knowledge, only way to set it to tow mode is thru the MCU.
Odd is that your 12V seems ok, but the MCU did not wake up.
Could it be you have a MCU1 and it also decided to die?

 

[EVRider-FL]

Contact Roadside Assistance via the app and they’ll arrange to transport your car to a service center. If the HV battery is dead, you’re still under warranty.

 

[VifferFun]

Thanks! I’m under warranty for the repair but not the tow. It’s a bit of a process — roadside assistance won’t “schedule” a tow for a time when the parking garage isn’t busy Is there any way I can “jump” the vehicle for 60 seconds to at least get into tow mode, or even better drive out of the parkade with a booster pack attached to the terminals behind the nose cone? So stressful I’m really worried about damaged the car while dragging it out of the garage

 

[vcor]

And be sure to advise Roadside Assistance of the parking situation so they can send the appropriate tow truck (that will fit). Ignoring the low ceiling (not sure how that will work out), the tow operators can deal with a car that can't be put in tow mode. They will either drag the car up onto the flatbed or use dollies under the wheels to move it.

Never knew the app can show you the last alerts!

Let us know how it works out.

 

[vcor]

I sort of doubt a 12v jump will work, but worth a try. It may be the 12v is too low to power up the MCU, but ok for smaller stuff like lights. If the jump gets the MCU up and running, then it should be easy to set Tow mode. Tow operators that work with Teslas should be able to do this for you as well, but not all tow operators can do it.

 

[vcor]

Very unlikely, but did you try and drive the car? You don't need MCU to be operating to drive. Just get in and select drive and carefully see if the accelerator moves the car.

 

[VifferFun]

Thanks! Yeah, I defintiely let Roadside Assistance know abot the parkade issue. They won't let me schedule an appointment in advance. I'm out of the city today, so I'll try calling them again tonight. I'm worried that they'll damage the car dragging it out the there. I just replaced the control arms too

 

[howardc64]

Your 12V is low because HV pack contractors aren’t closing to recharge it. Door will still present. Some lights on but mcu are won’t boot. Need to jump to turn on mcu and put in tow mode. Jump post behind nose cone. I think Tesla had slight variations on jump post on various years so look it up.

Doubt you can drive it. Sounds like HV pack is down or not closing the contractors so drive unit has no HV power even if you jump 12v.

 

[VifferFun]

I did try to drive it, but the gear selector doesn't do anything at all

 

[VifferFun]

Thank you! I'll try the jump to at least get into tow mode!

 

[VifferFun]

Quick update:

I tried getting the MCU to wake up using a lithium booster pack (NOCO GB70) on the service terminals, but no luck I experiementing by opening/closing the driver door and number of times, and then I saw the screen flash on and then immediately off -- so I thought there maybe be some hope! I kept trying with the door open/close and eventually the screen turned on again. It was on for about five seconds which was enough for me to get into the service menu, but not long enough for me to find "Tow Mode" -- argh!! I kept trying the open/close door but the screen would no longer turn on.

At this point, I went and got my Dad's lead-acid based booster (one of the big ones). I connected it to the terminals for bit, and after afew mins I was able to wake the MCU for about 30-60 seconds, which was long enough to get it into tow mode. That's one problem solved!!

The parking garage was super busy, but by about 12AM it was finally cleared out. I got my two brothers and my Dad to push as I steered/braked (no power steering or braking, but managable). Luckily I was parked in a location that was all downhill and pretty easy to exit the parkade We pushed it to an outdoor space right outisde the parkade exit, which was a perfect location for a tow truck.

I called Tesla Roadside assistance (really nice representative!), and they had a truck there within an hour. Tesla also covered the cost of the tow since the batter is under warranty

Anyways, I'm just really happy that I was able to get my car towed to Tesla unharmed!

Also, in case anyone is knowing, the "Toweye" hook for my 2015 is located under the frunk carpet liner. I found it really odd that Tesla makes you pull out the liner to get access to it, and that this isn't mentioned in the manual I think newer models have the hook in a more obvious/visual location.

Thanks everyone for your help!

 

[vcor]

Glad you got it working enough to get it out of the garage. I suspect the 12v battery is dead/shorted and was pulling down the voltage so that an external source of limited capacity wasn't enough to pull up the voltage to that usable by the MCU. Smart going with a big booster. In hindsight, I should have suggested to disconnect the car's 12v battery. Your first booster pack would have likely worked then.

 

[android04]

Glad you got it working enough to get it out of the garage. I suspect the 12v battery is dead/shorted and was pulling down the voltage so that an external source of limited capacity wasn't enough to pull up the voltage to that usable by the MCU. Smart going with a big booster. In hindsight, I should have suggested to disconnect the car's 12v battery. Your first booster pack would have likely worked then.

The more likely reason that the NOCO GB70 didn't work was because it needed to be put in Boost Mode by pressing and holding down the Boost button. That bypasses the reverse polarity protection that won't allow it to work if the 12v battery voltage is too low.

 

[VifferFun]

Thanks for the technical explanations!

I forgot to try putting the NOCO into manual override (which I think is what you meant by Boost Mode). I think I tried pressing/holding that button once, but nothing changed with the other LEDs (ie the LEDs were still “chasing” and the boost LED was still lit up white) so I assumed the manual override wasn’t needed because I had the jumpers connected properly.

Oh well, as least it worked haha! If the bigger battery pack didn’t work I would have tried an old-school booster cable from an ICE car (but shhhhhhh, don’t tell ICE drivers I said that! )