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That very loud and painful "clunk"


Sig Model S + Sig Model X + Model 3 Resv
Jun 21, 2012
As I sit waiting for roadside assistance, I can tell you that I now know that very loud "clunk" that precedes an entire car shutdown.

Tonight, as the light turned green on my way home, I accelerated and +BAM+ it felt like I got rear ended. The car immediately fell flat acceleration-wise, the direction/gear indicator turned red, and messages started popping up... "PULL OVER SAFELY... car is shutting down", "car needs service", "car may not restart", and eventually "12v battery low - car may not restart". I pulled over on the hill I was on and guided it to a side street, where we pushed it into a parking lot. After sitting for a few moments the car powered back up, Tesla advised me no current alerts were on the car and that I should be able to drive. At the next light, CLUNK again as I tried accelerating.

Luckily I was with some other owners at a local meet up event. They took the wife and kids home for me, and another driver stayed behind to take me home, I'll head there after we get it loaded and headed to the st Louis service center.

As I understand it from reports here, it sounds like I am due for a bit of major surgery with this one.

More to come...


Sig Model S + Sig Model X + Model 3 Resv
Jun 21, 2012
The service center said they will get to it first thing, it's being towed there. It may mean a new b/c/d pack, unknown at this point what the cause is, we just know that the contractors are disengaging.


Sep 21, 2012
Greater Cincinnati
Wow, horrible news Flasher! I hope she gets fixed soon.

This message has me a bit paranoid now. Just tonight as we sat at a traffic light I heard a clunk and it felt like we had been very lightly rear ended. I turned on the rear camera, and the car behind me was way back. My wife felt it too. We thought it was very weird, but shrugged it off.

We didn't have any car problems driving home, but now I'm wondering if that clunk was actually something internal in the car...


Sig Model S + Sig Model X + Model 3 Resv
Jun 21, 2012
You'll know it... this one is a major clunk followed by all sorts of bells and whistles going off... and it's unlikely to happen while just sitting there (although I suppose it could happen...)


S Sig #255
Oct 21, 2012
So Cal
Is it just me or has there been a surge of pack failures reported recently? Edmunds was the most recent and reported very similar symptoms as FlasherZ reports here.

@FlasherZ - how many miles on the odo?

My bet: drive unit.

My bet: HV Battery
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Sig Model S + Sig Model X + Model 3 Resv
Jun 21, 2012
19500 miles. I suspect battery at this point, as I sat in the car the symptoms got progressively worse. When the flatbed arrived, we were unable to get it to power up the drivetrain - car needs service, 12v battery low - and it wouldn't go into gear. I was able to get it into tow mode so it could be dragged into the truck. As of 12:15 the 12v system had gone dead and I lost remote telemetry. If it were drive unit, my guess is that I wouldn't have lost the 12v system charging.


Dec 19, 2008
congratulations may be in order, you just may be a few days away from a brand new traction battery/inverter combo... hope it gets sorted quickly and has a happy ending!
Yes, Tesla replaces both the traction pack, and drive unit when the inverter fails. Although I wouldn't count on a "B" battery. Some of the latest A battery cars had their pack replaced with a refurbished "A" pack.


Jul 15, 2012
This is the high voltage battery. You will get whatever battery they have in stock, possibly even my gently used old A pack. Hopefully, you get a new D though. Good luck Flasher. It appears that A packs fail at an unusually high rate (at least 3 Sigs in 3 weeks). This could be costly in the long term to owners and Tesla.


May 23, 2012
So what exactly causes the loud clunk? Is it a single battery exploding inside the pack? Is it some sort of huge arcing inside the electronics?


Apr 4, 2012
San Antonio, TX
I am worried, if I am to order my car next week as I literally am, should I expect troubles like this or like the 12V battery dying? I wonder if they fixed all these kinks in the system already or if I will eventually see it being a new owner and getting my car in 3-4 months.

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