An inverter is a part of hybrid cars that changes the type of electricity from the battery so it can be used by the electric motor. It's important for making the car run properly.
This unit is a special part in hybrid cars that helps the car use both electricity and gasoline. It works like a motor and a generator together, making the car more efficient.
An isolation fault is a problem where electricity is leaking in the car's system. This can cause parts to not work right and shows up as an error code.
Transmission fluid is a special oil that helps keep the parts of an automatic transmission working well. If it gets dirty or has too much metal in it, it can cause problems with how the car drives.
A double fluid drain and fill is when a mechanic removes the old transmission fluid and puts in new fluid, then does it again. This helps to make sure the transmission has clean fluid for better performance.
High voltage means there's a lot of electrical power, which can be dangerous. In cars, this usually happens in electric or hybrid vehicles, and you have to be careful around it.
An EV is a car that runs on electricity instead of gas. It has big batteries that power an electric motor, making it different from regular cars that use fuel.
Shielded cables are special wires that keep electricity safe inside them and stop other signals from messing with it. In electric cars, they are often orange to show they carry high voltage and need to be handled carefully.
The Toyota Highlander is a type of car called an SUV, which is bigger than a regular car and has more room for passengers and cargo. The hybrid version uses both gas and electricity to help save on fuel, making it a good option if you want to be kinder to the environment. People talk about it because it's reliable and great for families.
All-wheel drive means that all four wheels of the car get power from the engine, which helps the car grip the road better, especially in rain or snow. This is useful for driving in different weather conditions.
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Hi, it's Mark.
I'm here with Bernie Pawlik, Pawlik Automotive in Vancouver.
Vancouver's best auto service experience.
Multiple winners of best auto repair in Vancouver, as voted by their customers.
And we're talking cars.
How you doing, Bernie?
Doing very well.
So today's guest is a 2011 Toyota Hollander Hybrid.
What was happening with this vehicle?
So this vehicle came in with an inverter problem, which we'd rectified, but it turned out there
was a few problems on top of that, which we eventually traced to where in the transmission
are the motor, the motor generator transmission unit.
So hybrids are a very complicated piece of machinery, electrical, mechanical, and kind
of running through the motor generator transmission, which is this weird complicated piece of
machinery.
What was the mileage on this vehicle?
Yeah.
So this vehicle had quite high mileage.
It was about 280,000 kilometers, which is, you know, in miles, I think that's about
180 or something.
It's up there.
So it had some good use and I guess in all fairness things will go wrong on a vehicle
of that mileage, even a reliable Toyota.
All right.
So there was problems with the transmission.
Let's have a look at some pictures.
Yeah.
And so how we got here, I mean, there were problems with the inverter and
we replaced it.
And then after a road test, we were getting a fault code for a isolation fault, which is
basically electrical leakage in the system.
So we made some tests related to that.
Everything seemed to be fine.
The next area we looked at was what's the quality of the transmission fluid because
if the fluid is contaminated, there's too much metal in the fluid.
It can cause isolation fault codes.
So we drained the transmission fluid and this is what we found.
And you can see that it's a bit reddish, but there's a lot of gray.
And all that gray is metal filings.
All the shiny bits there.
All the shiny bits, the hideous amount of metal filings in the transmission fluid.
And we talked with the owner about it and they said that they'd had the transmission
fluid replaced recently.
We called the shop that had done it and he said, yeah, I remember that car.
The fluid was very black and dirty.
So this is like not even very old fluid that we're draining out here and
it's full of metal filings.
What's this here?
So this is draining out some cleaner fluid.
So we basically did a double fluid drain and fill.
Basically drain the fluid out, filled it up with fresh fluid,
road tested the vehicle for a little while, came back, drained it again.
So this is the fluid that came out.
Still had a tiny bit of metal in it, but very, very minimal as you can see.
That's how the fluid should look.
But we did a second drain just to ensure we got out as much particulate crap as
possible and so did a second fill.
And obviously the fluid would be much cleaner from the second one,
which we didn't drain out.
And that removed the trouble codes and all those things.
An assumption that perhaps the vehicle's okay at that point.
Well, we basically left it with the customer saying, hey, you know what?
This transmission's got severe wear inside and we don't know how long it's
going to last.
It may be finished by tomorrow and might be six months, a couple years.
You never know.
But basically, in fact, it had three transmission fluid changes.
It's pretty severe.
So we wrote test the vehicle extensively for an hour, drove fine.
No codes, no warning lights figured, hey, okay, great.
Unfortunately, the next day it failed again and the transmission needs to be
replaced.
So we're still pending their approval or decision on doing it.
But that's where we're at.
So you mentioned to me earlier that you did some research on this and
there's something inside these transmissions that will cause this?
Yeah, there's a metal plate that wears out inside the transmission.
I actually haven't disassembled one myself to look at it.
Apparently there's a metal plate inside that will come loose and
it starts rubbing in a way it shouldn't and that just creates a bunch
of metal that goes through the system.
So what happens with metal filings in the system, it will sort of short
circuit or create electrical conductivity in the fluid which you don't want.
So the fluid is special in these transmissions.
We only use the genuine Toyota fluid just to make sure there's no weird issues.
And why would that be an issue?
Why is I think an isolation fault?
Why would that be an issue for safety even?
Well, these vehicles have high voltage, 300-ish proximate volts.
It fluctuates around.
That's deadly voltage.
If it were to leak into the car, for instance, and you're holding the steering wheel,
all of a sudden the 300 volts went through the steering wheel could kill you.
Or if you step out of the vehicle and one of your body's grounded and
the other's electrically charged.
So they put a lot of safety features.
All the wires and cables, if you ever look on an EV or hybrid,
they're all orange-covered cables and those are all shielded cables.
You have to be very careful when you're doing electrical testing.
You can't do the old-fashioned way of piercing through the insulation to test it
because the moment you do that, you've now shorted the isolation to the voltage
and the cables junk.
So very precise procedures to do testing on these kind of things.
But it's all there for safety.
And any minute amount of electrical leakage in the system, it's all monitored.
Any minute amount of electrical leakage will basically shut the hybrid system down.
And so what would that possibly, maybe even probably, have done to the inverter?
Well, it could have damaged the inverter.
If there's too much material, metals, and things are conducting in the wrong way,
it could cause an inverter failure.
So it might well be the reason the original inverter failed,
but inverters do fail from time to time even in a perfect running system.
So you can't really necessarily blame that on the transmission,
but it's a possible cause.
And this hybrid, this is just specific to around this kind of vintage of Toyota Highlander hybrid.
Yeah, they made this model for, I can't remember how many years now,
but the Highlanders are slightly more problematic and have a few more issues than Prius's do
because they're a little more complex.
They have a third motor in the rear to drive the all-wheel drive system.
Three motors.
Three motors, yeah.
Three times as much fun.
So yeah, the more complexity you add, it makes for a more useful vehicle
and more stuff goes wrong.
If you're looking for service for your hybrid, any maker model or electric EV,
the people to see in Vancouver are Pawlik Automotive.
You can book online at pawlikautomotive.com
or you can call them to book your appointment at 604-327-7112.
You have to book ahead.
They're always busy.
Pawlik Automotive, Vancouver, BC, Canada.
Thanks so much for watching and listening.
Thanks, Bernie.
Thanks, Mark, and thank you for watching and listening.
About this episode
A 2011 Toyota Highlander Hybrid presented with an inverter issue, which led to the discovery of severe wear in its motor generator transmission unit. With 280,000 kilometers on the clock, the vehicle's transmission fluid was found contaminated with metal filings, indicating significant internal damage. After a double fluid change, the car initially seemed fine but failed again shortly after. The discussion highlights the complexities of hybrid systems and the potential safety risks associated with electrical leakage, emphasizing the importance of using genuine parts and proper maintenance.
