Aggressive traction control?

[Xariann]

Hello,

I am a new Yaris owner. My wife and I bought the car about 3 weeks ago and we encountered 2 instances where traction control seemed to have been very aggressive. I have seen the light flicker very briefly a few times, but these two incidents were slightly different.

The Yaris is a 2016, hybrid model.

The first one happened when we approached a roundabout. We don't really drive the car aggressively, and we thought we were slowing down fairly gradually (my wife was on the wheel at the time). Suddenly the  car breaks so much that I literally get pushed forward and the seat belt tensed up, as it does when it thinks you are moving too suddenly. I asked my wife what that was about and she said it was the traction control kicking in.

The second time I was slowing down, again gradually, on a piece of straight road. I was on the wheel so I saw the traction control light come on and the car breaked suddenly, again. Not as much as the first time, but too much compared to how much I was pressing the pedal.

Prior to this we used to drive cars with 16 or 17 inch wheels, fairly wide tyres. One of them was a Gen 7 Celica, which was lowered and had two degrees camber on the rear wheels... So that one was on rails.

The other was a BMW E46 with big wheels. Before that we had an E36... I wouldn't say it had huge wheels, but it didn't have traction control and considering that we'd be more aggressive with that one we never lost control of it, and it definitely didn't have traction control and was a rear wheel drive car.

I guess I worry that someone who is a bit impatient and decides to tailgate us will suddenly find themselves inside our boot if our car decides to break for apparently no reason.

Should I get this checked out?

[FROSTYBALLS]

Hello Elisabetta - welcome to Toyota Owners Club.

Your car will have an electronic stability program (also known as ESC or VSC) rather than just traction control. Traction control just limits wheelspin in the driven wheels by either applying braking to those wheels and, in some circumstances, reducing engine power. ESP operates slightly differently in additionally using various sensors to detect loss of steering control, applying braking to individual wheels to correct either oversteer or understeer and improve the stability of the vehicle. ESP became compulsory on all new cars sold in the EU from Nov 2014. If you're uncertain whether your car's system is operating correctly, get your dealer to check it.

 

 

 

 

 

 

[Xariann]

Thank you, I'll have a chat with them and see what they think.

[Peter S]

It sounds like "brake assist" is cutting in too soon,
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◆ Brake assist
Generates an increased level of braking force after the brake pedal
is depressed when the system detects a panic stop situation.
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I think it measures the velocity of the brake pedal movement and kicks in when it thinks it needs to,

[Xariann]

According to this post my Yaris has one too:

http://blog.toyota.co.uk/toyota-car-safety-braking-technologies#brakeAssist

So I'll mention it to the dealer. Thank you :)

[MEP's Yaris GS]

On 06/04/2016 at 5:47 PM, Peter S said:

It sounds like "brake assist" is cutting in too soon,
-------------------------------------------------------------------------------------------
◆ Brake assist
Generates an increased level of braking force after the brake pedal
is depressed when the system detects a panic stop situation.
-------------------------------------------------------------------------------------------
I think it measures the velocity of the brake pedal movement and kicks in when it thinks it needs to,

Not quite, its more a case of keeping the brakes on full if pressure it released slightly but not fully on the pedal after full braking has been called for - this is because its been shown that just before impact, in a lot of cases people start releasing slightly on the brake pedal. Unless this is something else I'm on about, but I'm sure its Emergency Braking Assist.

TBH OP sounds like ABS activating rather than traction control - same light comes on for both, or at least it does in my Prius. Not tried it in our Yaris. Will happen if one wheel isn't slowing at the same speed as the other - IE bit of oil or grease on the road.

[Xariann]

The light that comes on is 100% traction control. ABS doesn't even flicker. :)

[MEP's Yaris GS]

1 hour ago, Xariann said:

The light that comes on is 100% traction control. ABS doesn't even flicker. :)

Traction control is a combination of ABS, ASR and ESP where fitted. I assume you're on about it only being for ESP?

[Peter S]

On my Yaris there isn't a dedicated TRC light or ABS light all I have is a slip indicator which is a combination of TRC EBS ABS and VSC. This function can be turned off by a button near the handbrake.

[Xariann]

MEP said it was two lights. So I said the traction control light is what comes on, the traction control light is on the left side of the wheel, the ABS is on the right side, so that's what "I'm on about."

Peter - You are now making me wonder, although, I'll have to have a look at the dash again. Regardless whatever it is - it came in when it didn't make sense but it hasn't happened again since. 

[MEP's Yaris GS]

20 minutes ago, Xariann said:

MEP said it was two lights.

No I didn't, I said same light comes on for both in the Prius, and I assume the Yaris is the same.

The light I'm talking about it the one Peter S has posted - Slip Indicator.

[FROSTYBALLS]

10 hours ago, MEP's Yaris GS said:

Traction control is a combination of ABS, ASR and ESP where fitted.

It is the other way round - ESP/ESC/VSC incorporates yaw control into ABS via a variety of sensors, and may also incorporate traction control (TCS/ASR). 

The warning light mentioned above is a typical indicator for when ESP comes into operation. On our previous 2012 i20 the ESP sometimes operated in icy conditions. Haven't had the same occur (yet) with our 2015 i20 - have had the lane departure system operate though.

[Xariann]

11 hours ago, MEP's Yaris GS said:

No I didn't, I said same light comes on for both in the Prius, and I assume the Yaris is the same.

The light I'm talking about it the one Peter S has posted - Slip Indicator.

Ah my bad! Reading this on the mobile while trying to work, sometimes I have to read really fast ;)

[Xariann]

Right so I attached it (can't be bothered to get out and get my manual or take a pic of my dash, it's Sunday morning and I am being lazy).

Although that dashboard is not exactly the same as mine (some lights are not in the same position) you have an ABS light and an anti-slip/traction control/whatever you want to call it light. On my dash, the ABS is where you see it there, while the other light is on the left side. My manual also explained the behaviour of each light, this one I found doesn't. I can't remember if it just said that the ABS light comes on when you start the car and then to signal a fault with the system, rather than coming on when it's operating (like the traction control one does). It's inconsequential at this point :)

Now, the issue has not happened again. But after reading all you guys have suggested I suppose it could have been an icy road when my wife was driving or it could also be that she lifted the foot a bit too suddenly as we were approaching a roundabout and we aren't used to the brake pedal yet. This car kind of brakes a bit, then it sort of hits a "dead zone" where it keeps braking gradually and it feels like it's braking less compared to how much you are squeezing the pedal, then you start squeezing it more and the car stops really fast. So she might have tried to squeeze it a bit more as she approached the roundabout, realised the car was slowing down too much and lifted a bit too fast. 

As to when I was driving it, I am trying to remember the type of road I was on, it wasn't the most even road in the world so maybe the wheel slipped while driving on a hole?

You have to understand that this is the first brand-new car we ever owed... The newest we owed for any length of time was a Celica Gen 7 pre-face lift, a used one, with just the ABS. The car was basically on rails. Then we owed an E36, without all the traction control and rear wheel drive, and again we didn't really manage to spin it, it never lost grip or anything like that. The E46... we didn't own that one for long enough as it was a lemon.

So all this is new to us, we understand it, just felt it was coming in a bit too soon. We weren't in any danger to lose control yet the car almost shot me out of the front window the first time (okay I am being a bit dramatic here, but it was overcompensating).

[FROSTYBALLS]

50 minutes ago, Xariann said:

Right so I attached it (can't be bothered to get out and get my manual or take a pic of my dash, it's Sunday morning and I am being lazy).

Isn't it Saturday, or have the clocks gone further forwards for BST this year?

As I said previously, if you are unsure the system is working properly, get a dealer to check it. They should be able to check for any fault codes.

[Xariann]

1 minute ago, FROSTYBALLS said:

Isn't it Saturday, or have the clocks gone further forwards for BST this year?

As I said previously, if you are unsure the system is working properly, get a dealer to check it. They should be able to check for any fault codes.

I'll just blame it on the coffee.

Yeah we are giving them a call.

[Akaay]

Hi i recently had my steering rack replaced on a toyota yaris mk3 2012 and now my traction control light is displayed on the dash and the button is being unresponsive also i noticed that my horn has now stopped working is there a sensor somewhere near the rack that might not be connected or is it another issue

[Gerg]

9 hours ago, Akaay said:

 is there a sensor somewhere near the rack that might not be connected or is it another issue

I think you are almost correct with that question.  There is a module that sits under the steering wheel, between the indicator and wiper controls, sometimes called a 'clock spring cable'.

It is designed to allow the horn control to electrically connect to the rest of the car, without the constant moving of the steering wheel causing the wire to break.  The module also contains a sensor to detect where the steering wheel rotation is pointing, which is used by the car for vehicle stability/traction control etc, I think.

When this module is refitted after your repair, the road wheels should be set at the straight ahead and the module fitted to the steering column in the exact middle of its anti-clockwise/clockwise maximum travel, otherwise the flexible cable inside it can become unduly stressed.

It sounds like it is this module that has failed (age/miles?), or less likely, has become disconnected.  The connectors have a very positive retaining clip, I would definitely not expect it to come undone by itself, unless it was simply not pushed in firmly enough, or has been damaged.  These connectors are easily checked if the trim surrounding the steering wheel (upper half/lower half, where your ignition key goes into) is removed.  I don't have a Yaris, so you'll have to find out how the 2 screws (?) are best accessed and how the in-built clips are detached from one another (can be fragile - thin plastic).

If it is this, I would guess that a new part is about £250 and fitting is less than an hours labour, but there is supposition in all the above, hopefully someone who has had this happen, or works on these cars regularly, will see your post....

I removed/replaced this part on our Auris about 3 weeks ago, yours is probably very similar.

How many miles has the car done?

I imagine the repair was not done at a Toyota garage (cost!).  What were the symptoms that caused the rack to be replaced, incidentally?