GR Yaris POWER STEERING FAILS mid turn on the Nürburgring
- Thread starter Dragos_DreS
- Start date
Don’t really know but to fast is the wrong word for it is not that fast. Mid turn bit earlier it turns of epas and you are left on your own a for half a second then it is coming back. For me it is not quick turning of the wheel or fast movement. (I am not that close to the limit)
- Dec 27, 2021
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Michael Knight
Totally Hooked
It so hard to get out the code and to troubleshoot this….
So I booked a track day
next Thursday. It’s the worst. Hopefull I don’t get the fault? The dealership feels like don’t track the car. It not under warranty. Reads the instruction manual and it stands with extra oil changes it is warranty on track. If there is no mods.
Michael Knight
Totally Hooked
I really cannot see how track driving would damage the car if warmed up and cooled down properly and with extra maintenance needed as you said. Its quite easy to demo the issue and on track its much safer to do if needed.It so hard to get out the code and to troubleshoot this….
So I booked a track day
The dealership feels like don’t track the car. It not under warranty. Reads the instruction manual and it stands with extra oil changes it is warranty on track. If there is no mods.
Michael Knight
Totally Hooked
Got the same code. When asked from Toyota they answered (again) - this is normal, its ok for this car.
I started questioning how this aligns with their motto "Pushing limits for the better".
Any better comments from other Toyota representatives? I feel it bit funny if they claim this normal. Maybe its ok for Corolla.
I started questioning how this aligns with their motto "Pushing limits for the better".
Any better comments from other Toyota representatives? I feel it bit funny if they claim this normal. Maybe its ok for Corolla.
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A post from wiborg engineering contains some interesting points about the features of the stock suspension geometry at the front:
"the contact patch moves outwards increasing this lever arm and thus giving larges turning forces during braking (and more load on the steering gear itself) so an adjustment helps here as well."
www.gr-yaris.co.uk
The inherent limitations of the suspension geometry is overloading the EPAS causing it to temporarily derate. Not sure there is much more that can be done easily to EPAS. Has anyone tried the wiborg engineering front arms to see if this improves the situation with the EPAS derating on track?
en.wiborg-engineering.se
"the contact patch moves outwards increasing this lever arm and thus giving larges turning forces during braking (and more load on the steering gear itself) so an adjustment helps here as well."
Wheel Alignment
www.gr-yaris.co.uk
The inherent limitations of the suspension geometry is overloading the EPAS causing it to temporarily derate. Not sure there is much more that can be done easily to EPAS. Has anyone tried the wiborg engineering front arms to see if this improves the situation with the EPAS derating on track?
Wiborg Engineering Circuit race geometry kit - Front Yaris GR | Wiborg Engineering
The Wiborg Engineering kit contains all parts needed to replace the front lower control arms and greatly improve the handling and grip potential of the front suspension of the yaris GR. Contains all parts needed for installation, kit is a bolt-on solution and require no machining or modfication...
en.wiborg-engineering.se
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I had the EPAS issues before getting the wiborg arms, and still have them with the arms fitted.
Trailing the brakes makes it happen pretty reliably - I've kinda got used to it now, but would be keen to find a solution.
My car is modified enough that taking it to Toyota to look it isn't really an option!
Trailing the brakes makes it happen pretty reliably - I've kinda got used to it now, but would be keen to find a solution.
My car is modified enough that taking it to Toyota to look it isn't really an option!
Michael Knight
Totally Hooked
Got a generic response from Toyota Auto Finland Oy - not an issue but a normal feature. In practice they did not really analyse it, just said its no issue.
To get get a proper feedback would need to get the issue analyzed by right factory engineers.
not sure if have right contacts but could try. alhtough its kind of difficult as its not the official way so changes of getting it fixed is kind of 0.05%.
Does the issue happen with cars that have their ECU swapped to Motec or Syvecs?
To get get a proper feedback would need to get the issue analyzed by right factory engineers.
not sure if have right contacts but could try. alhtough its kind of difficult as its not the official way so changes of getting it fixed is kind of 0.05%.
Does the issue happen with cars that have their ECU swapped to Motec or Syvecs?
My thought too, but is it about the abs taking too much of the available electric power or just the applied braking making it too hard for the epas to work.
I've never had the problem occur without trailbraking.
Michael Knight
Totally Hooked
no need to brake that hard to get the steering issue on, light trail brake is enough.
- Dec 27, 2021
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are you sure? and add brake fading (cooling issue) to it as well!
edit: I would think the whole brake system was working overtime and wondering ...what's going on here
Did the wiborg arms make any difference?
Otherwise would you recommend the wiborg arms in terms of performance vs any increased nvh?
I'm wondering if the arms have slightly improved the loading that a v2 with aim of further reducing load on the steering by adjusting the geo would make it less of an issue.
Also wondering if the mk2 yaris might have this fixed.
Like you say it is manageable to drive through the temporary loss of steering if you are used to it.
My car was off the road for about 6 months during which time I had the Wiborg arms fitted, and I've only been out once since then, so I don't know if I can really give honest back-to-back feedback on how much difference they made. The car is fantastic to drive - super neutral, will 4-wheel drift under power, very predictable and confidence inspiring, but it was like that before too 
I didn't notice a huge difference with NVH, but I'm pretty far down the road of rose joints, and I don't think I'd notice much more NVH over the bloody verkline gearbox mount!
I do have some clearance issues with the inside of the wheels rubbing on the arms at full lock, but that might be related to mega (-4/5 deg) camber and/or slightly loo low ride height, I haven't really looked in detail.
I haven't driven the same tracks with/without Wiborg, but I wouldn't say there's a huge difference in encountering the EPAS issue, trailing the brake will pretty much make it happen with or without Wiborg. This is with 255 A052 tyres on a 9" wheel - I didn't encounter it with OEM wheels/tyres, but only did one track day like that.
I would be surprised if it was fixed in the mk2, but you never know. There was a comment above about disconnecting the front ARB making it go away - I'm not super keen on changing the F:R balance, but it would be interesting to see if it does "fix" the problem.
I didn't notice a huge difference with NVH, but I'm pretty far down the road of rose joints, and I don't think I'd notice much more NVH over the bloody verkline gearbox mount!I do have some clearance issues with the inside of the wheels rubbing on the arms at full lock, but that might be related to mega (-4/5 deg) camber and/or slightly loo low ride height, I haven't really looked in detail.
I haven't driven the same tracks with/without Wiborg, but I wouldn't say there's a huge difference in encountering the EPAS issue, trailing the brake will pretty much make it happen with or without Wiborg. This is with 255 A052 tyres on a 9" wheel - I didn't encounter it with OEM wheels/tyres, but only did one track day like that.
I would be surprised if it was fixed in the mk2, but you never know. There was a comment above about disconnecting the front ARB making it go away - I'm not super keen on changing the F:R balance, but it would be interesting to see if it does "fix" the problem.
CerN
Totally Hooked
