Front drive unit failure at 40 miles

[rydb]

Bosch drive units in these current quad motor Rivians. The new dual motors coming next year will be in house. I'd imagine at some point there will be in house quad motors, too.

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[LaunchGreen]

Percentage of delivers with major issues continues to rise. Gotta be above 5% now.

 

[godfodder0901]

Bosch drive units in these current quad motor Rivians. The new dual motors coming next year will be in house. I'd imagine at some point there will be in house quad motors, too.

Coincidentally, today, I was wondering about this very issue, what happens if there is a motor failure. Specifically, I was wondering if the vehicle would/could disconnect the failed motor and allow one to proceed, using only the good motors. It sounds like that is a definite maybe.

That’s a definite no. It allowed it to limp so many feet to basically allow you to get off the road. It won’t limp along on 2 motors or 3 three motors. It appears when something goes down its designed to be incapacitated. The tech couldn’t even trick it into moving.

The motors are Bosch sourced, but the drive units are in house. Also, in this case the front drive unit failed. Had it been the rear you could, in theory, decouple the rear unit and continue to drive in a relatively normal manner in the short term.

 

[mindstormsguy]

Early Audi E-Trons had tons of failed early drive units. So Rivian is in good company here .

 

[OverZealous]

Not-so-early Tesla Model S's had lots of drive unit failures, too.

I know there aren't that many trucks built yet, but I find it interesting that most serious failures so far seem to be only one vehicle reporting it. If it is a single failure of each type, then it sorta falls under the sh!t happens category, with something like a ~ 1/2000 chance (which is high, but not astronomical).

It would be interesting to see the internal report from Rivian. I'm curious, was it a motor manufacturing fault? A fault on Rivian's side? Something happened in shipping?

 

[Doublemfarms]

Not-so-early Tesla Model S's had lots of drive unit failures, too.

I know there aren't that many trucks built yet, but I find it interesting that most serious failures so far seem to be only one vehicle reporting it. If it is a single failure of each type, then it sorta falls under the sh!t happens category, with something like a ~ 1/2000 chance (which is high, but not astronomical).

It would be interesting to see the internal report from Rivian. I'm curious, was it a motor manufacturing fault? A fault on Rivian's side? Something happened in shipping?

According to everybody I talked to at Rivian service, and I talked to a lot of them, this is the first time they have seen this on a production unit. I was out under the impression they have seen it but only on pre production units

 

[the long way downunder]

With four motors, I expected software to allow the vehicle to continue with three dead motors and for there to be a dialog on the touch screen showing the fault and allowing the driver to drive the vehicle … "I'm in death valley, no phone signal, just keep going" sort of thing.

The vehicle is owned by the owner, not by the factory. While the factory wants to protect its warranty costs, or continue to debug it's new product as a beta in the hands of the early adopter customers, the owner has the prerogative to keep going even if the "low oil" light might result in further damage or failure … it must be the decision of the driver in control of the vehicle at the time, not the business interests of the corporation.

 

[Zoidz]

This drive units are Rivian designed or off the shelf???

The motors are Bosch OEM, the rest is Rivian designed.

The failure could be mechanical, electrical or electronic since the drive unit contains everything including the inverters. That's why I was curious about the failure details. Unfortunately, the error message is a bit general.

Charged EV Magazine - VP of Propulsion:
"
Charged: You said that there are symmetrical drive units, so you have four identical sets of motors and drives?

Richard Farquhar: That’s correct – we have four identical motors, left and right, front and rear. Every wheel has the exact same amount of torque and power available to it to maximize performance. We achieve over 14,000 Newton-meters of grounded torque at the wheels combined and 125 miles per hour maximum speed. With the fixed-ratio single-speed gearbox there is no need to change gears, no need for twin speeds. This maximizes efficiency in terms of losses from gear meshing while achieving all of our performance targets.

The inverters are one of the jewels in the crown of this propulsion system, and are fully designed in-house. We designed a dual power inverter device integrated into the drive unit assembly, which allows very efficient control of two electric motors from one inverter assembly. We focused a lot on electrical efficiency from the battery to the inverters to the motors and on to the wheels. Having one dual combined inverter per axle allows us to maximize that electrical efficiency and therefore use the energy to maximize the vehicle’s range.

Charged: Was the motor designed in-house as well?


Richard Farquhar: For the e-machines, we work with a partner to design the core electromagnetics and motor assembly, and then package them into our drive unit. It’s similar to battery modules in that we work with partners to source the cells and then design and develop the modules and pack in-house exactly as we want it.

So, the electric motors are unique to Rivian in terms of how they’re integrated into our drive unit assembly, how they’re mounted, how the inverter connects with them, how the cooling connects with them, and how they’re oriented in our gearbox.

"

 

[Zoidz]

With four motors, I expected software to allow the vehicle to continue with three dead motors and for there to be a dialog on the touch screen showing the fault and allowing the driver to drive the vehicle … "I'm in death valley, no phone signal, just keep going" sort of thing.

The vehicle is owned by the owner, not by the factory. While the factory wants to protect its warranty costs, or continue to debug it's new product as a beta in the hands of the early adopter customers, the owner has the prerogative to keep going even if the "low oil" light might result in further damage or failure … it must be the decision of the driver in control of the vehicle at the time, not the business interests of the corporation.

I mostly agree, especially since Rivian could have a confirmation dialog forcing you to acknowledge damage liability if you choose to continue driving.

Also note that the warning dialog provided says "drive with caution..." That implies that some failures might allow you to continue driving, but with this particular failure, perhaps the failure itself was a show stopper. Or it could be an unhandled fault mode in the software, so it defaulted to worst case scenario. We'll probably never know until we get an API, or a bootleg of dealer diagnostic software. I have a bootleg of BMW ISTA, would love to have that for the Rivian.

I'm hoping that Rivian improves the details displayed to the customer, and as they learn more about fault modes, that they improve things such as "limp mode" options.

 

[Forager]

Only the rear drive unit has a decoupling device. Like godfodder said, perhaps the rear could fail and the vehicle still be drives me, but that’s up to the ECU (is it still an ECU on an EV?) and how Rivian programmed it.

If the front is toast, you definitely aren’t moving because that drive unit has no decoupler and is fixed. It’s like not being able to take a vehicle out of Drive and having a seized engine.

 

[the long way downunder]

I mostly agree, especially since Rivian could have a confirmation dialog forcing you to acknowledge damage liability if you choose to continue driving.

Also note that the warning dialog provided says "drive with caution..." That implies that some failures might allow you to continue driving, but with this particular failure, perhaps the failure itself was a show stopper. Or it could be an unhandled fault mode in the software, so it defaulted to worst case scenario. We'll probably never know until we get an API, or a bootleg of dealer diagnostic software. I have a bootleg of BMW ISTA, would love to have that for the Rivian.

I'm hoping that Rivian improves the details displayed to the customer, and as they learn more about fault modes, that they improve things such as "limp mode" options.

I think they call it "turtle" mode. Funnily enough, the stuff that will actually break an EV and prevent it from moving are not detected by software … if you snap a half shaft, all it could do is report the wheel sensor is faulty and ABS would be disabled. : )
rant-ish reminder of Tesla evils:

Tesla has had this problem and made it worse over the years … their priority is their warranty liability. I thought they had changed their misunderstanding of the world when there was a natural disaster in Florida (wind storm?) and Tesla unlocked all vehicles that had software restrictions on battery kWh (there used to be a model S that had 65 kWh in an 85 kWh pack, IIRC) which was a nice PR stunt and potentially helped a few folks, but they have never agreed to let the owner own the vehicle. If you walk out to your Tesla in the morning and it decides it doesn't want to move because it owes its allegiances to Tesla, not you, then you're SOL. I think that's criminal. There must always be an "OK" button to turn on the vehicle and get going. If there's a wildfire coming up the hill (as there was a few years ago) and the Tesla said "nope" we could be incinerated rather than risk some problem getting worse … that was the day I literally parked my old Model X out of way so we could drive away in another vehicle, and planned to sell it and get a vehicle that will start without a cellular signal, without a software connection to a keyfob or a mobile phone, etc. : ) That old X is gone, my old 3 Performance is gone (because people wanted to pay too much for it) and we have a new X, a Ford F-150 Hybrid and a Rivian … in one year gone from three Teslas to three different brands. Many of my early adopter neighbors and friends who were Tesla devotees have since set their "never going back" opinion on EVs and ordered a Range Rover or are waiting for a Rivian, Lightning or Kia/Hynundai, etc. Tesla needs to look beyond the short term trend of making a million Ys and a million Cybertrucks and put an end to their quality and service snafu.
I'm not interested in taking delivery of another Tesla at least until they build the Roadster – even that is looking old to me and Tesla is looking like a typical corporation now – it's no longer the lively startup disruptor breaking the rules, now it's the stodgy corporate suit where "policy" is the explanation for why the customer is no priority, just profits. Rivian is already smelling like a corporate suit. Talking with the guide is like tech support at Apple … ever so helpful sounding, but no intention and no capacity to actually help. So far, Rivian support at the service center has been solid, but their corporate policy is to actively prevent the customer from talking with field service staff. Hopefully they wake up from this misapprehension because the competitors are coming.

 

[rydb]

Even though they’re permanent magnet motors, unless they’re physically jammed, you should still be able to turn them even if there is some drag. Certainly seems like you’d be able to at bare minimum limp along at 20 mph.

 

[the long way downunder]

Only the rear drive unit has a decoupling device. Like godfodder said, perhaps the rear could fail and the vehicle still be drives me, but that’s up to the ECU (is it still an ECU on an EV?) and how Rivian programmed it.

If the front is toast, you definitely aren’t moving because that drive unit has no decoupler and is fixed. It’s like not being able to take a vehicle out of Drive and having a seized engine.

I'm not thinking of something elegant like disengaging a faulty motor, I'm thinking with one corner of the vehicle ripped off in a collision or while off-roading, resting on three wheels (or two) with the other corner dragging on the ground and no coolant, the vehicle must be designed to respond to the driver and keep going if at all possible.
The executives instructing the developers are exceeding their legal boundaries by disabling the vehicle to suit corporate policy. This "right to repair" disaster is getting worse. Tesla has talking about the robotaxi as being something the customer pays to "own" but never owns, only leases and is obligated to return after some period, no matter what, non-negotiable. It's analogous to people being forced to rent because they don't "qualify" to get a mortgage … they can somehow qualify to pay $2000 to rent, but not $2000 to pay a mortgage and eventually own their home … somehow "sentenced" to be in perpetual debt and own nothing. (I'm not the first to observe.) Hopefully Rivian doesn't end up like Tesla.

 

[DaveA]

So....if this happens at say....60 mph.....what happens??

 

[Max]

Does anyone know if Tesla or other EVs have the inverter outside the drive unit? If they are the weakest link, it may make sense to make them easy to replace. Not that we could do anything about it but it would be nice to know what failed.

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