How does a failed drive unit cause all those errors?
EDIT: I'd at least share the details on the TeslaMotorsClub forum. There are some pretty knowledgable members.
Photograph by Tim Murray
A friend offered to sell his 2014 Tesla Model S P85D for just $10,000. All-wheel drive. 700 horsepower. He had tired of it.
I couldn’t resist.
There were some catches, of course: a Tesla badge on the hood and a warranty that ran out years ago.
At the time, the Tesla brand carried the controversy of a weirdo at the helm and long waits for replacement parts. It hadn’t yet become associated with the systematic disassembly of our government. So, I figured the baggage was just the price of admission–a footnote in my ownership rather than an overarching theme.
I was apprehensive but did my research. I found a bunch of people still driving these cars with over 100,000 miles on them, so I took the leap, sold my Nissan Frontier, and brought home my new-to-me EV.
For the past three months, I had been daily driving the car with no issues other than having to replace an air shock–just took a few hours in the shop to replace.
The Tesla was fast, comfortable and always had a full “tank” when I got behind the wheel. My wife and I took it on a few road trips, and I was, to my surprise, enjoying life with an EV. Call it a party trick, but I enjoyed showing friends and family how quickly it could launch off the line. It also made a great camera car for me to use at our track tests.
A week or so ago, that all changed. On the way back from a trip to the FIRM, I got an ominous message on the dash: “Car may not restart.”
And sure enough, the next day the car did not restart.
What could it be? Well, there were a few things to check out. I had no idea how old the 12-volt battery was, so that was step one in the diagnosis. Turns out it was only 2 years old but completely dead.
Photograph by Chris Tropea
Could this simple fix get my car running again? We fully charged the replacement battery–checked it with a load tester, in fact–and still the car wouldn’t start.
We eventually got the car to boot up and enter the service mode, and it was showing codes for an error with the high-voltage system. The high-voltage system, we reasoned, wasn’t able to maintain the smaller, 12-volt battery.
Now I knew I was looking at a much bigger issue, and at this point I decided it was time to bring it to an expert.
Photograph by Chris Tropea
One problem: The closest Tesla service center had a 50-day wait, and I kind of needed a car for the next 50 days .
So it was off to a third-party shop that specializes in Teslas and was able to get to my car in just a few days. We loaded it into the trailer and headed west to Ocala to drop it off.
Photograph by Chris Tropea
I eagerly awaited the hopefully good news.
After six days, I got the word: The rear drive unit had died and must be replaced.
This was my worst-case scenario.
Installing a remanufactured rear drive unit from Tesla–carrying a four-year, 50,000-mile warranty–is going to cost $8959.10 out the door.
The drive unit itself carries a price of $7043.04. The estimate lists $962.50 for installation. Also needed: about $125 for other fluids plus $235 for an alignment. (Turns out that mine is way out of spec.)
Could we do the job here at GRM now that our new shop was up and running? I see used drive units on eBay for $4000 to $6000, but am I willing to learn how to repair a high-voltage system with just my laptop guiding me? And on a car that still has value to me? One that I need to drive on a 1000-mile trip in two weeks? Sorry for not being brave, but I’m going to default to the experts (and a guaranteed repair timeline) on this one.
I realize that this bill nearly equals what I paid for the entire car. My saving grace is the fact that I bought the car at such a low price.
So, the question I now face: Once it’s fixed, do I keep the car or sell it before something else expensive breaks? I think I have made my decision, but what do you all think?
How does a failed drive unit cause all those errors?
EDIT: I'd at least share the details on the TeslaMotorsClub forum. There are some pretty knowledgable members.
Are used units available and able to be programmed to work? Seems like there should be plenty of them out there.
Yikes. Thanks for sharing. What exactly is a drive unit?
This is the same GRM that dug into an unserviceable Porsche transmission to fix it for pennies. Let's see some more creative approaches, like can we fix the control electronics or get a good used unit from a junkyard? Model S rear drive units are sought after for swaps, can you sell the old one to someone who's looking to DIY a fix?
Buying heavily depreciated high dollar cars always comes with this sort of risk. Meanwhile, I had to put an $1800 reman engine into a $2500 Toyota pickup so I understand the pain.
CyberEric said:Yikes. Thanks for sharing. What exactly is a drive unit?
The motor/transmission.
In reply to Sonic :
Used units are available but all will have the same issue that caused mine to fail. A bad seal that lets coolant leak into the inverter and fry the electronics. You can replace them and code in the new unit to the car but with no knowledge of the inside of the unit you are taking a $4k-$6k gamble in parts.
How many miles does the Tesla have on it ?
In reply to californiamilleghia :
It has 83,000 miles on it.
I think that understanding what caused your failure should help you decide whether you keep the car. I sold my 2014 P85+ (not the dual motor) with, I think, 160,000 miles on it. The battery capacity was comfortably at 80-85% or so, the motor still pulled like hell, and I had no issues with reliability--so they can go the distance. As long as you don't have some sort of goofy un-diagnosed issue plaguing the car.
You said a seal failed and killed your drive unit. That's fairly straight-forward (i.e. you didn't have some electrical surge that fried stuff and you can't figure out where that came from). Does the front drive unit have a similar seal? Is there a reputation for that rear seal failing, and does the front drive unit have a similar reputation? I mean, if you fix it, and you don't expect it to fail again, why not keep it?
That's a heart-stopping repair bill, and it would sink me--but it's not that dissimilar from what a Porsche owner would experience if their 997/987 engine had bore scoring or a RMS failure.
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