GR Yaris POWER STEERING FAILS mid turn on the Nürburgring

so maybe better to go for 1000CCA LiFePo just to be on the safe side with power delivery? Mine is 600CCA which should be the same as stock is rated but who can tell.
Then again, what kind of current the power steering requests at its peak - would be fun to know. Hard to think it would use more than for example starter motor..
 
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I've also had the same experience of temporary loss of steering at the ring and other circuits and he loaded up. I'm running 9.5" protrack wheels with ar1s. When I get the loss of assistance Im still able to steer but it is very hard.
A friend of mine works for OEMs to calibrate Epas steering. He has said this behaviour is likely due to derating of the assitance due to overloading/overheating of the motor. Epas systems have inbuilt protection to temporarily reduce power to allow the system to cool down. He said there is really not much that can be done as it's very hard to uprated
epas systems as it is all integrated through the Canbus. Wonder if the corolla suffers with the same issue...
 
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Crackfox said:
I've also had the same experience of temporary loss of steering at the ring and other circuits and he loaded up. I'm running 9.5" protrack wheels with ar1s. When I get the loss of assistance Im still able to steer but it is very hard.
A friend of mine works for OEMs to calibrate Epas steering. He has said this behaviour is likely due to derating of the assitance due to overloading/overheating of the motor. Epas systems have inbuilt protection to temporarily reduce power to allow the system to cool down. He said there is really not much that can be done as it's very hard to uprated
epas systems as it is all integrated through the Canbus. Wonder if the corolla suffers with the same issue...
Click to expand...
Seems to be an issue on Gr86 aswell https://www.ft86club.com/forums/showthread.php?p=3486168
 
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Crackfox said:
I've also had the same experience of temporary loss of steering at the ring and other circuits and he loaded up. I'm running 9.5" protrack wheels with ar1s. When I get the loss of assistance Im still able to steer but it is very hard.
A friend of mine works for OEMs to calibrate Epas steering. He has said this behaviour is likely due to derating of the assitance due to overloading/overheating of the motor. Epas systems have inbuilt protection to temporarily reduce power to allow the system to cool down. He said there is really not much that can be done as it's very hard to uprated
epas systems as it is all integrated through the Canbus. Wonder if the corolla suffers with the same issue...
Click to expand...
Maybe the go light go fast - strategy has gone too light in this one. Would be cool if Toyota would accept the fault and replace power steering with more capable unit but dont see this likely scenario.
 
topic is also debated in GRC forums. there one suggested that it might be software calibration issue. I sent the question to my service guy, hopefully they get the issue reported also towards Toyota but not really sure if Toyota is active with these kind of reports. If we would get more reports towards Toyota, maybe they could do something for it.

As JPN Kinto program has option to adjust steering feel or weight, they have likely tools to change the power steering settings.

"I haven't driven the corolla hard enough to test for this, but what you're feeling is the torque sensor saturating due to the torsion bar bottoming out. Toyota will need to re-tune the steering to fix it but it shouldn't require any hardware changes. I'd complain to the dealer, enough complaints should warrant a fix."
 
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Happened to me too at the bottom of foxhole at the nurburgring.
Well to be precise the cut off happened just after the compression.
When you go very fast at this place the compression is very hard and you have to steer a little bit so it make sense.
I doubt it's an heat related issue because at this place you almost don't steer at all before.

I was on 4S tyres on OEM wheels.
Can't remember if I had my KW V4 yet.

Now on 235 AR-1 (8.5 wheels) with KW V4...might happen more, we'll see.

But it didn't happen at all during 2 trackdays on 245 cup2 tyres on a small racetrack with lot of hard turns.

I have to say that my current setup is lighter than OEM setup.
8.5 TC105 Weedssport wheels + very light nuts + 245 Cup2 tyres = 500g lighter than OEM setup....
And also I have Girodiscs that are lighter than OEM discs (~1.8 kilos !)
Overall 2.3 kilos ligher on rotating mass
All of this might help a little bit.

I might be at the nurburgring next weekend ;)
 
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991RS said:
Happened to me too at the bottom of foxhole at the nurburgring.
Well to be precise the cut off happened just after the compression.
When you go very fast at this place the compression is very hard and you have to steer a little bit so it make sense.
I doubt it's an heat related issue because at this place you almost don't steer at all before.

I was on 4S tyres on OEM wheels.
Can't remember if I had my KW V4 yet.

Now on 235 AR-1 (8.5 wheels) with KW V4...might happen more, we'll see.

But it didn't happen at all during 2 trackdays on 245 cup2 tyres on a small racetrack with lot of hard turns.

I have to say that my current setup is lighter than OEM setup.
8.5 TC105 Weedssport wheels + very light nuts + 245 Cup2 tyres = 500g lighter than OEM setup....
And also I have Girodiscs that are lighter than OEM discs (~1.8 kilos !)
Overall 2.3 kilos ligher on rotating mass
All of this might help a little bit.

I might be at the nurburgring next weekend ;)
Click to expand...
its not heat issue, its maybe power steering not managing the required force ie not powerful enough.
wish there was a easy fix for this as this is quite annoying issue. don't like steering sticking when its most needed.
 
I have reported the problem to my locale Toyota workshop. And I am getting a new battery. Thanks to the very nice warranty. Have no ide if it will fix it but I think Toyota thinks it is very cheap to replace battery so will see.

I gave them the dates I was on track and they checked faults cods on that day. So if you know what to look for there is fault code on it. But not the same code every time. Don’t remember the exact text and code !!!OFCOURS and did not write it down…..
 
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Pelle said:
I have reported the problem to my locale Toyota workshop. And I am getting a new battery. Thanks to the very nice warranty. Have no ide if it will fix it but I think Toyota thinks it is very cheap to replace battery so will see.

I gave them the dates I was on track and they checked faults cods on that day. So if you know what to look for there is fault code on it. But not the same code every time. Don’t remember the exact text and code !!!OFCOURS and did not write it down…..
Click to expand...
Please post detail of errors and if that fix helped. My car was in service analysis and they did not find any codes.
 
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Just came across this thread
... My power steering on track went a tiny bit stiff for like a second or less only a few times. When chucking it into a corner.

Running standard shocks with eibach springs.... 9.5 wide wheels with nankang AR1.

Maybe it's the bigger wider wheels giving the power steering more to do.🤔
 
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Michael Knight said:
Please post detail of errors and if that fix helped. My car was in service analysis and they did not find any codes.
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Will do when my little Toyota shop have time for the car. Was no warning warning. But the text after the code was like :driving fast and turning much. 😜 was not saying epas not working. More in tone to :turning to fast or turning irraticly.

Don’t really remember got happy they started doing something about it after saying same thing 2 times befor this.
 
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Pelle said:
Will do when my little Toyota shop have time for the car. Was no warning warning. But the text after the code was like :driving fast and turning much. 😜 was not saying epas not working. More in tone to :turning to fast or turning irraticly.

Don’t really remember got happy they started doing something about it after saying same thing 2 times befor this.
Click to expand...
Ok please post detail where the error was generated and what spesific error it was. I could try to find it with my shop too.
 
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Michael Knight said:
topic is also debated in GRC forums. there one suggested that it might be software calibration issue. I sent the question to my service guy, hopefully they get the issue reported also towards Toyota but not really sure if Toyota is active with these kind of reports. If we would get more reports towards Toyota, maybe they could do something for it.

As JPN Kinto program has option to adjust steering feel or weight, they have likely tools to change the power steering settings.

"I haven't driven the corolla hard enough to test for this, but what you're feeling is the torque sensor saturating due to the torsion bar bottoming out. Toyota will need to re-tune the steering to fix it but it shouldn't require any hardware changes. I'd complain to the dealer, enough complaints should warrant a fix."
Click to expand...
Hello guys, I didn't come here since a while and now I read this answer:

"...but what you're feeling is the torque sensor saturating due to the torsion bar bottoming out."

This is a very interesting information. I don't know who exactly said that, but this is definitely the best explanation for this issue: not due to overheat, not due to current power loss, but simply due to calibration.

In fact, if the torque sensor is constantly reporting data about the torsion bar angle position (or angular speed) so that the EPAS adjusts the assistance accordingly, it could be understandable that the EPAS stops to function when there is no valid data to work with, due to "the torsion bar bottoming out" causing sensor overloading.

As a software engineer, this sounds like a bug to me, like if the edge case where the torque sensor sends "extreme" values (or just no change in value, if the bar bottomed out) is not handled properly in the software.
 
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Pelle said:
I have reported the problem to my locale Toyota workshop. And I am getting a new battery. Thanks to the very nice warranty. Have no ide if it will fix it but I think Toyota thinks it is very cheap to replace battery so will see.

I gave them the dates I was on track and they checked faults cods on that day. So if you know what to look for there is fault code on it. But not the same code every time. Don’t remember the exact text and code !!!OFCOURS and did not write it down…..
Click to expand...
mind asking the data from them? I would love to share this with my service rep. going there monday to fix the wiper motor.
 
Pelle said:
The car is is in on the 12/6 will take all the data they have/the fault code so we can share white you😊
Click to expand...
cool looking forward to this! my service rep did not find any fault codes which is strange - guess it should store some kind of data. or is there multiple places where to look for codes?
 
Here is the Code my Guy is going on.

The line is what is related to the steering
 

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