Power steering died when I was on the Freeway

[Ultramaroon]

Originally Posted by woode

Yes, I am positive in my case. I literally could not turn the steering wheel more than a few inches using all my strength. When the car is moving it is generally easier to turn without power steering at all.

I looked for an actual copy of the TSB. Found the number but didn't have any more luck.

According to what I found the pump motor would overheat because it was fighting a filter clogged with rust. That does NOT fit with your experience. Did you ever find out what really happened?

[woode]

Originally Posted by Ultramaroon

I looked for an actual copy of the TSB. Found the number but didn't have any more luck.

According to what I found the pump motor would overheat because it was fighting a filter clogged with rust. That does NOT fit with your experience. Did you ever find out what really happened?

No, it only happened that one time.. and I sold the car not long after so never had the TSB performed.

[Ultramaroon]

Originally Posted by woode

No, it only happened that one time.. and I sold the car not long after so never had the TSB performed.

I wonder if Mazda isn't hiding anything because that sounds REALLY disturbing.

[Tomking]

Originally Posted by woode

Yes, I am positive in my case. I literally could not turn the steering wheel more than a few inches using all my strength. When the car is moving it is generally easier to turn without power steering at all.

That is exactly what has happened to me, I put my full weigh on it and was only able to pull a few inches. Whether it was lost of power or locking issue, it is very series issue.

For those in doubt, I am in my 50's and have been driving lots of car without power steering in the early 80 so I would know what it feel like.

My "Steering locked" issue remained until I turn off the car and leave it for 10 secs before turning it on again. It was not cutting in and out like some mentioned here.

[Ultramaroon]

Originally Posted by Tomking

That is exactly what has happened to me, I put my full weigh on it and was only able to pull a few inches. Whether it was lost of power or locking issue, it is very series issue.

For those in doubt, I am in my 50's and have been driving lots of car without power steering in the early 80 so I would know what it feel like.

My "Steering locked" issue remained until I turn off the car and leave it for 10 secs before turning it on again. It was not cutting in and out like some mentioned here.

Well, sir, you are both patient and persistent to revisit your thread.

Please accept my apology. You indeed must have quite a pair.

Now I am genuinely a bit nervous. This is the stuff that kills people.

[Ultramaroon]

Originally Posted by Sarlacc

Anyone got any input on how electric power steering works in general, and on our cars in particular?

If you're sitting still with the engine off it's possible to turn the steering wheel a few degrees either direction and feel a light springy resistance.

The steering wheel is not coupled to the shaft in this arc. This is only the error input. Think of it like a gaming joystick. Turn a bit to the right. It commands the servo to turn the shaft to the right until the shaft and steering wheel are back in alignment.

Now for the hard part. The failure modes would be determined by how the reduction gear is coupled to the shaft and specific choices made in the design of the controller itself. I would have to see schematics and all the related code (because no one designs purely analog systems anymore) to decipher it any further.

[mav1178]

Originally Posted by Tomking

That is exactly what has happened to me, I put my full weigh on it and was only able to pull a few inches. Whether it was lost of power or locking issue, it is very series issue.

For those in doubt, I am in my 50's and have been driving lots of car without power steering in the early 80 so I would know what it feel like.

My "Steering locked" issue remained until I turn off the car and leave it for 10 secs before turning it on again. It was not cutting in and out like some mentioned here.

Again: is your steering locked, or did the assist get disabled? Even the link you presented in your first post says that this is a power steering ASSIST issue.

What I doubt right now is your assessment of the issue at hand, being that everyone else in this thread seems to think it's not an issue. Perhaps you can provide the actual diagnosis and parts replaced so we can take a look?

Originally Posted by Ultramaroon

This is the stuff that kills people.

.. only if it's an actual lock issue.

If my steering was locked, I would not be able to turn it at all, let alone "a few inches".

-alex

[Ultramaroon]

Originally Posted by mav1178

.. only if it's an actual lock issue.

If my steering was locked, I would not be able to turn it at all, let alone "a few inches".

-alex

I am fully converted to OP's argument. He confused the issue with his defensive response about people not owning the car and how it's hard to turn when it's off but this sounds different.

[mav1178]

Originally Posted by Ultramaroon

I am fully converted to OP's argument. He confused the issue with his defensive response about people not owning the car and how it's hard to turn when it's off but this sounds different.

Then the question is:

with the car in the "On" position but engine not started, is the amount of force needed to turn the steering wheel the same as when the initial problem occured?

If so, it's not a lock issue.

If not, it's an isolated lock issue that is most likely related to a bad steering input sensor, motor, or both.

-alex

[HunterGreene]

Frankly, I am surprised that the thread is still on-topic, given that both Tcoat and Ultramaroon have chimed in.

I've never noticed any probems with my PS, and that was including some days this past summer where we almost hit 100 F (around 38-40 C).

Originally Posted by chaoskaze

Ur high school must be amazing, the stupidest thing I ever did was cramming 9 guys into 1 Corolla...

Not to assist the threadjack, but stupidest thing I participated in HS was the annual "race to dinner" that my HS cross-country team would do before the last invitational every year. Take about 2 dozen teenage boys, cram them into 6-7 cars (usually cheap sedans), and then have them race to the restaurant of choice, no rules except get there first. Some of the things I saw (passing in the oncoming lane on a 5-lane road, brake checking, running lights that were VERY red, amounts of speeding that would make Ken Gushi blush), would make me piss my pants these days.

It was damn fun, though

And one last thing...Thanks for the new sig, Ultra

Originally Posted by Ultramaroon

...they don't stick on. They flop open.

[Ultramaroon]

Originally Posted by HunterGreene

And one last thing...Thanks for the new sig, Ultra

Wow! I am honored. You held on to your last one for a "very long" time.

[Ultramaroon]

Originally Posted by mav1178

Then the question is:

with the car in the "On" position but engine not started, is the amount of force needed to turn the steering wheel the same as when the initial problem occured?

If so, it's not a lock issue.

If not, it's an isolated lock issue that is most likely related to a bad steering input sensor, motor, or both.

-alex

Agreed. @Tomking, how would you answer this?

[Tcoat]

Originally Posted by HunterGreene

Frankly, I am surprised that the thread is still on-topic, given that both Tcoat and Ultramaroon have chimed in.


And one last thing...Thanks for the new sig, Ultra

FOSD bylaw #2 - No Order Member shall interfere with or deliberately derail any thread within the Technical Topics Sub Forum unless; i) the op of said thread initiates such derailment, ii) the op has received all possible assistance on the topic but refuses to believe any of it, or iii) the thread has run beyond any possible resolution of the issue (i.e. any cricket related thread)

This thread is still viable and therefore remains inviolate under the bylaw.

[Sarlacc]

A quote form this thread: www.ft86club.com/forums/showthread.php?t=11810&page=3

Originally Posted by mobybrz

Yes, there is a power steering ECU. It is connected to the CAN, the TRQ1 and TRQ2 steering sensors, and an angular resolver (angle sensor). It outputs to the power steering motor.

What you mention between the IS versions isn't (or at least is extremely likely to be) different ECUs. It is more likely different *maps* juts like we are all aware of with ECUTEK on the engine ECU. Theoretically, it should be possible to perform the same reverse engineering work on the power steering ECU to allow maps to be edited or adjusted. I wouldn't be surprised if there is a different EPS map between the FR-S and the BRZ given the differences in suspension.

As it stands, I would imagine the GT86/FR-S/BRZ steering maps based on mostly on speed and driver applied torque. There is might be/likely is an influence from the VSC mode settings, steering angle, gear, and measures of yaw angle (side slip/rotation, the same measure that drives VSC intervention).

To give an example, one could theoretically create a map that is designed to assist the driver i an accident avoidance manuever on the highway. The ECU could detect a likely avoidance maneuver and provide an increased steering torque initially (effecitvely increasing the drivers turning rate) before ramping down the provided torque (slowing the drivers turning rate) to prevent an overcorrection and help dampen any potential for a tank slapper. You could use (again theoretically) anything coming over the CAN to influence the map.

And that sounds perfectly reasonable and enlightened to me.
I still think there's an open question here. Is the power steering mechanically able to make the steering harder than it'd be if it just lost power?
I mean, it really shouldn't. I've seen software glitches in my car, a couple of times it flashed a lot of warning lamps and wouldn't start before I got out, locked the doors with the remote, opened it and got in again.
And that's fine. A software glitch that will kill me is not.