Would not have bought a Toyota for the spouse if I knew this.

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Maybe I'm late to the game, but after driving GM vehicles for many years and a few Toyota's...this is something that would have made a big decision in my vehicle purchase.

We picked up a lightly used 2014 Highlander XLE AWD last summer and all has been great. I bought this for my wife to haul the kids and have a reasonable level of safety features to aid her in most driving situations.

A good part of my decision was that if she was caught in some bad weather....i.e...snow, that with good tires and AWD, her commute would pose less of a risk of being stranded.

What really caught my attention to all of this, was if there is...say.....an oxygen sensor issue, or basically an emissions related issue, that the vehicle

DISABLES THE AWD SYSTEM!

Are you freaking kidding me?!

If I'm still able to drive the vehicle, why does the AWD system and stability control need to be disabled?

I can understand a transfer case or differential issue, but this is not acceptable.

I've been around vehicles a long time, I can see one arguement that the system may not function up to it's full capacity..maybe, but if I can drive it with no other restrictions, why does the AWD and traction control have to be disabled.

I'm very seriously re-thinking this purchase and sell the vehicle. I DID NOT buy this to help keep my wife and kids safe, to have this possible situation lurking beneath.

Just some info for anyone that may have the same concerns.
 
I know nothing about Toyota . So , my only thought is to find a Toyota forum , that hopefully has a sub-forum dedicated to your vehicle . Maybe you can get some more information / help in that way .

Now , real world , has this ever happened while you or your wife were driving the vehicle ? Does it flash an indicator , kind of like a SES or CEL ?

Is this referring to an engine o2 sensor or one in the inside of the vehicle ?

Best of luck to you , :)
 
I will surely get on a Toyota forum, but there's a lot of people here that are passionate about their vehicles and I feel it's a good place to start.

She was driving it and called me that the AWD system is disabled and displayed on the screen. Took it to the dealer and they told us the oxygen sensor was showing a faulty reading and turned out to be a loose wire in the connection in the wire harness.

We were then told that this is normal. I said...this is not normal from a safety standpoint.
 
AWD doesn't do much for keeping them safe anyway. Most crashes in slippery conditions are due to an inability to stop. Or turn. For that you need true winter tires. Not just good tires.

Anyway, if the light is off, your system is good, right?

So, get it fixed...it's not likely to come on again soon...

My kids' Corolla has gone 200,000 miles without ever having a CEL.
 
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Unfortunately it is normal-the xB in my sig has a nagging evap code which has been hard to track down-and it disables traction control & ABS because it's there. I have no idea why. Fortunately it does better in bad weather with the electronic nannies disabled, and I'm unlikely to sell it before it's basically a worthless pile of rusty scrap anyway.
 
Originally Posted by Astro14
AWD doesn't do much for keeping them safe anyway. Most crashes in slippery conditions are due to an inability to stop. Or turn. For that you need true winter tires. Not just good tires.

Anyway, if the light is off, your system is good, right?


I've always had dedicated snow tires for her, the tires on there now are very good in snow so I'm going to leave them on for now.

If you haven't driven a newer Toyota when it gets loose then you may be surprised. I agree AWD just keeps you going...but that's just it, what happens on a hill or in deep snow?

Going around a turn and the car gets loose, the stability control works instantly and works remarkably well..almost too good to believe.

But the whole point of something like this to disable the AWD, Trac control , etc is not acceptable.


Light is off now, all is good.

Sure, the added axle loads the engine more when engaged, but we're not talking excessive load.
 
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Originally Posted by Astro14
AWD doesn't do much for keeping them safe anyway. Most crashes in slippery conditions are due to an inability to stop. Or turn. For that you need true winter tires. Not just good tires.

Anyway, if the light is off, your system is good, right?

So, get it fixed...it's not likely to come on again soon...

My kids' Corolla has gone 200,000 miles without ever having a CEL.


I'm not disagreeing, but there is also the consideration that if it "fails", does it fail into 2wd that is front or rear? If it fails as 2wd rear, it can really catch someone not used to driving a rear wheel drive car in quite a surprise, and most certainly cause an accident. I don't know that system, and I am not saying that is the case in this instance, but I do know if the AWD on my wife's car failed, it would be rear wheel drive...which would pose a problem, as I'm quite certain she has never driven a rear wheel drive car in her life.
 
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This has to be one of the stupidest things I've ever heard. Got a CEL for something minor? Make the vehicle significantly less safe!
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The Highlander defaults to FWD in this scenario, no added torque to the rear when disabled. Even FWD with some Blizzaks will work very well in most all situations.

I just cannot wrap my head around disabling these safety features over something like this.
 
Originally Posted by bullwinkle
the xB in my sig has a nagging evap code which has been hard to track down-and it disables traction control & ABS because it's there.


Oh yeah....forgot...thanks....in addition to the above mentioned...it also disabled the ABS on mine as well.

Good thing an evap situation or O2 sensor keeps the brakes from pulsing.
 
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Originally Posted by DriveHard
Originally Posted by Astro14
AWD doesn't do much for keeping them safe anyway. Most crashes in slippery conditions are due to an inability to stop. Or turn. For that you need true winter tires. Not just good tires.

Anyway, if the light is off, your system is good, right?

So, get it fixed...it's not likely to come on again soon...

My kids' Corolla has gone 200,000 miles without ever having a CEL.


I'm not disagreeing, but there is also the consideration that if it "fails", does it fail into 2wd that is front or rear? If it fails as 2wd rear, it can really catch someone not used to driving a rear wheel drive car in quite a surprise, and most certainly cause an accident. I don't know that system, and I am not saying that is the case in this instance, but I do know if the AWD on my wife's car failed, it would be rear wheel drive...which would pose a problem, as I'm quite certain she has never driven a rear wheel drive car in her life.


Since the Highlander is available as either FWD or AWD, the default will be FWD.

No worries there.

It's no Alfa, if that's what you're saying...
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I think that the AWD and traction control systems rely heavily upon the engine and transmission inputs. If the computer detects a fault, it can no longer reliably predict the speed or power output, so the safest option is to disable AWD and traction control.
 
So you don't live in a snow belt, and you're worried about your O2 sensor causing a fault at the SAME TIME that conditions are snowy? Probably the same probability as being struck by lightning. I thought I worried about small things. Besides you still have FWD with all season tires.
 
Originally Posted by dadto2
I think that the AWD and traction control systems rely heavily upon the engine and transmission inputs. If the computer detects a fault, it can no longer reliably predict the speed or power output, so the safest option is to disable AWD and traction control.


In hear ya.....also sounds like the engineers couldn't/ didn't design a fail safe to keep the wheels turning.

Other manufacturers have found a way to make it work.
 
Originally Posted by NormanBuntz
So you don't live in a snow belt, and you're worried about your O2 sensor causing a fault at the SAME TIME that conditions are snowy? I thought I worried about small things. You still have FWD with all season tires.


May not live in the "snow belt" but we get our fair share of snow and ice.

It's also about my wife and kids having a sense of security...call me "over-protective"...I don't put a price on safety.

I wasn't worried about the given scenario...until it happened. That's how I found out the situation existed.
 
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Originally Posted by Astro14
AWD doesn't do much for keeping them safe anyway. Most crashes in slippery conditions are due to an inability to stop. Or turn. For that you need true winter tires. Not just good tires.

Anyway, if the light is off, your system is good, right?



+1 regarding control of the vehicle.

Are you sure that GM or others dont do exactly the same thing? There may well be real and good reasons why this, related to the way that AWD is set up and integrated in these vehicles. Keep in mind that you bought a car which kind of biases torque, when needed. Its not a legitimate 4WD system, but doesnt need to be. Its employment is much more casual, and an expectation of proper maintenance for all vehicle systems to be operational is not out of line.

And none of it helps you stop or control better on ice.

Originally Posted by DriveHard

I'm not disagreeing, but there is also the consideration that if it "fails", does it fail into 2wd that is front or rear? If it fails as 2wd rear, it can really catch someone not used to driving a rear wheel drive car in quite a surprise, and most certainly cause an accident. I don't know that system, and I am not saying that is the case in this instance, but I do know if the AWD on my wife's car failed, it would be rear wheel drive...which would pose a problem, as I'm quite certain she has never driven a rear wheel drive car in her life.


This should be a simple question, easily answered with a little searching. My cursory searching seems to indicate that the Highlander system is capable of 50/50 but actively controls to 100% FWD in ideal (or faulted I guess) conditions. This would make sense since the highlander is a car like the camry or Sienna, and these are FWD vehicles.

But need to go back again to stopping. If your wife doesnt understand about driving for the conditions, regardless of drive systems, there's potential trouble when traction gets low or ice is encountered.
 
Originally Posted by i6pwr
Originally Posted by Astro14
AWD doesn't do much for keeping them safe anyway. Most crashes in slippery conditions are due to an inability to stop. Or turn. For that you need true winter tires. Not just good tires.

Anyway, if the light is off, your system is good, right?


I've always had dedicated snow tires for her, the tires on there now are very good in snow so I'm going to leave them on for now.

If you haven't driven a newer Toyota when it gets loose then you may be surprised. I agree AWD just keeps you going...but that's just it, what happens on a hill or in deep snow?

Going around a turn and the car gets loose, the stability control works instantly and works remarkably well..almost too good to believe.

But the whole point of something like this to disable the AWD, Trac control , etc is not acceptable.


Light is off now, all is good.

Sure, the added axle loads the engine more when engaged, but we're not talking excessive load.


I'm honestly surprised by this as well.

The ABS being disabled by a CEL is, frankly, ridiculous. That's unsafe.

I drive a new(er) Toyota all the time. It got loose quite a bit when I had it in Colorado. With RWD, and a light rear end, it could be fun...but, I'm more of a grown-up than I used to be...

While the 4WD mode prevented me from getting stuck, I really had to plan ahead for braking, and be very cautious around the soccer moms in their SUVs who drove like bozos in the snow because they just "knew" that AWD made them invincible...

The stock Bridgestone Dueler tires were just plain lousy in the snow. Bad enough that I gave them away with 9,000 miles on them. It's got Nokian WR G3s on it now. Such a huge difference, that it's hard to describe. I've had the truck in Vermont a couple of times, and driven up to NYC in a couple of snow storms. Love those Nokians.

I think it's great that you got winter tires, by the way. Many in VA don't see the need...until they can't stop...

Going forward, while the CEL disconnect of safety systems would [censored] me off, too, the real question is one of economics. You've bought this. You've bought tires for this. To trade it now will cost you. The only limitation is IF the light comes on again. As long as she understands that the car is degraded if that happens, I think I would keep it. Shocking design flaw, yes, but the remainder of the reasons that you bought this are still true.
 
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