2013 Subaru BRZ -- Another Power Steering Failure & Troubleshooting Help

[BrettRS]

Hello All!


Last weekend, my girlfriend lost power steering in the BRZ and the warning light came on. She managed to get it home, but I am not comfortable with her driving the car without power steering, so she's currently driving my old truck.



The power steering failure is consistent in my limited testing after she got home and I drove it around the neighborhood. Sometimes, after turning the car off and back on, it will clear briefly and the power steering will work, but most times it just displays the failure as soon as the car is started. The car drives like a car with no power steering when the power steering turns off and it is now consistently turning off even directly on some cold starts.



I got out my handy OBDII reader, however the car is showing no logged codes or pending codes.



Obviously the first thing I did was search this forum for similar issues. I saw a number of threads on the issue. Tons of them don't have resolutions in the threads, others have suggested a few items:


1. Battery Failing under Load -- This was my first thought, as the battery in the car has been leaking gases since I got the car and I've been battling corrosion when I open the engine compartment. I took the battery to our local battery store yesterday, the load tested it, said it was failing under load. I got a new battery from them and installed it yesterday evening. A new battery did not resolve my issue.


2. Steering Angle Sensor -- Saw some posts about this from people who have taken their cars to the dealer, but most of them have reported that even after getting it replaced from the dealer, the failure continues.


3. Failed / Bad ECU -- This seems most likely. At a reported cost on the forums of about $1,500, I'm really hoping this isn't the issue, but this is what my head is telling me.



I really, really don't want to take it to the dealer, but I will if there are no further troubleshooting suggestions I can try at home that you guys might have. I just know if I do, it's going to be a big bill and I have enough of those right now.



I would love to try and resolve this on my own if there's anything else I can try other than code reading and the new battery, which I have already done. Let me know if anyone else has had this issue and has resolved it without taking it to the dealer, thanks!

[subaruslow]

Sucks, I hope you get it worked out. Keep us updated. There must be an expert on this issue that can help.

[Tcoat]

@ermax ?

[ls1ac]

The power steering is electric. Finding an intermittent electric problem can be very difficult. The dealer computer connection may be needed to keep from using the shotgun parts replacement method.

[BrettRS]

Originally Posted by ls1ac

The power steering is electric. Finding an intermittent electric problem can be very difficult. The dealer computer connection may be needed to keep from using the shotgun parts replacement method.

Yeah, it's basically constant now, so I'm going to loop around the neighborhood now for a bit and see if I can get it to throw a regular code at me, at least.

It's an automatic, 100k miles if that makes any difference for troubleshooting.

My fiat x1/9 had no clutch when I went to get it out of winter storage last weekend too, had to rollstart it in second and do loops in the school parking lot to not stall at the only light between my house and where the car was lol. I got it back but it's in pieces on my lift right now, I'm bleeding the clutch but haven't figured out if the easy minor cylinder failed or master cylinder that is a brutal repair job..

BRZ was before this issue, love to figure it out myself and get it back to running great again. If I figure anything out on my own tonight I'll let yall know.

Sent from my SM-G998U using Tapatalk

[pope]

are you sure the electric steering motor isn’t falling?

[humfrz]

I agree with @ls1ac.

I suggest you take your car into a shop and have it sorted out and fixed.

A car with the power steering going in and out, is not something that I would want my girlfriend driving.

I suggest you save your DIY urges for something less critical -

[BrettRS]

Originally Posted by humfrz

I agree with @ls1ac.

I suggest you take your car into a shop and have it sorted out and fixed.

A car with the power steering going in and out, is not something that I would want my girlfriend driving.

I suggest you save your DIY urges for something less critical -

I mean, no one is driving it right now as I said and it's a pretty simple problem to know if it's been fixed or not, but I don't have anything else to try so finna call them today.

Sent from my SM-G998U using Tapatalk

[alphasaur]

This sounds like a loose connection or weird short/capacitor issue. Did you try unplugging/cleaning connections related to the power steering? Fuse?

[BrettRS]

Originally Posted by alphasaur

This sounds like a loose connection or weird short/capacitor issue. Did you try unplugging/cleaning connections related to the power steering? Fuse?

I did, just the 80amp fuse in the engine compartment, looks OK.



Just some further thoughts after my test drive and attempt to get it to throw a code. I don't drive the BRZ often, it's my gf's daily, so not sure if it's new or unusual, but the idle seems to dip pretty hard about 3-5 seconds after starting. It always catches back up after it dips, but I can see it stutter down below a consistent idle and then pick back up to a consistent idle.



No codes on my test drive. Power steering always turned off within 10 seconds of moving in drive, sometimes on directly after restart, sometimes would come up off and then come on after rolling for a few seconds.



There is a firm lock bite when it does go, almost like you are hitting the steering wheel lock, and then it releases after a quarter of a second and you can steer without power steering. Again, unsafe to be driven, just troubleshooting.


Alongside the 'bite' when power steering goes out, there is an audible 'click' sound by my left knee when it goes out. Is the interior fuse box centered under the drivers knees or is it off to the left side? Any fuses in the interior box that anyone can suggest for me to specifically check, other than pulling and checking them all? (edit: I checked the interior fuse compartment, going to check and adding for my easy reference later when I work on it): 14ECU IG110AABS, electric power steering
9ECU IG210AEngine control unit1ECU ACC10AMain body ECU, outside rearview mirrors8OBD7.5AOn-board diagnosis system15AM17.5AStarting system19ECU IG210AEngine control unit


Any diagrams or guides where I may find the steering control harness or whatever that I have seen suggested may be loose? I think that's what you alluded to.



Still no codes and the Subi dealer can't get me in until next week, so more time to troubleshoot this weekend...


So, quick recap:


1. Still no codes
2. Dip in idle 3-5 seconds after restart (hot)
3. Steering lock 'feedback' when power steering does go out.
4. Audible click when PS goes by left knee, inside passenger compartment.



Anything else to try this weekend, I'm all ears and sockets.

[BrettRS]

Originally Posted by pope

are you sure the electric steering motor isn’t falling?

No, I have not determined if it could be related to the motor failing. Any idea if there would be a code from that failure, maybe eventually if I let the car run for longer?


Anyone familiar if there's anywhere I can test output voltage of the motor and see if it is in spec or perhaps failing to output required voltage?

[pope]

Originally Posted by BrettRS

No, I have not determined if it could be related to the motor failing. Any idea if there would be a code from that failure, maybe eventually if I let the car run for longer?

Anyone familiar if there's anywhere I can test output voltage of the motor and see if it is in spec or perhaps failing to output required voltage?

I can’t find a test procedure/voltage spec for the steering motor in the service manual. Just about every other vehicle component has a test spec so I’m surprised I can’t find anything for the steering motor. The service manuals are floating around the forum if you want to locate them and have a go at searching for the spec, maybe you’ll have better luck.

According to the the manual, Techstream can be used to test for intermittent connection failures in the wiring, if you have access to Techstream.

If the problem is in the steering angle sensor you should have warning lights for abs, traction control, and stability control because those all rely on the steering angle sensor.

The power steering motor is under the dash, I can’t remember its exact orientation, so it’s possible it’s above the left knee area and that’s what you are hearing.

There’s a “common” issue with these cars having the internal rubber coupler fail in the steering motor. It’s generally discussed as a “rattle fix” and I haven’t had the problem with my car, so I haven’t had the motor apart to know if the rattle could progress into failure, but it might be worth investigating.

[alphasaur]

Originally Posted by BrettRS

I did, just the 80amp fuse in the engine compartment, looks OK.



Just some further thoughts after my test drive and attempt to get it to throw a code. I don't drive the BRZ often, it's my gf's daily, so not sure if it's new or unusual, but the idle seems to dip pretty hard about 3-5 seconds after starting. It always catches back up after it dips, but I can see it stutter down below a consistent idle and then pick back up to a consistent idle.



No codes on my test drive. Power steering always turned off within 10 seconds of moving in drive, sometimes on directly after restart, sometimes would come up off and then come on after rolling for a few seconds.



There is a firm lock bite when it does go, almost like you are hitting the steering wheel lock, and then it releases after a quarter of a second and you can steer without power steering. Again, unsafe to be driven, just troubleshooting.


Alongside the 'bite' when power steering goes out, there is an audible 'click' sound by my left knee when it goes out. Is the interior fuse box centered under the drivers knees or is it off to the left side? Any fuses in the interior box that anyone can suggest for me to specifically check, other than pulling and checking them all? (edit: I checked the interior fuse compartment, going to check and adding for my easy reference later when I work on it): 14ECU IG110AABS, electric power steering
9ECU IG210AEngine control unit1ECU ACC10AMain body ECU, outside rearview mirrors8OBD7.5AOn-board diagnosis system15AM17.5AStarting system19ECU IG210AEngine control unit


Any diagrams or guides where I may find the steering control harness or whatever that I have seen suggested may be loose? I think that's what you alluded to.



Still no codes and the Subi dealer can't get me in until next week, so more time to troubleshoot this weekend...


So, quick recap:


1. Still no codes
2. Dip in idle 3-5 seconds after restart (hot)
3. Steering lock 'feedback' when power steering does go out.
4. Audible click when PS goes by left knee, inside passenger compartment.



Anything else to try this weekend, I'm all ears and sockets.

https://www.ft86club.com/forums/showthread.php?t=133606
this thread seems to have info on accessing the power steering unit, not sure if this is the right direction or not. Good luck.

[BrettRS]

Originally Posted by alphasaur

https://www.ft86club.com/forums/showthread.php?t=133606
this thread seems to have info on accessing the power steering unit, not sure if this is the right direction or not. Good luck.

Thanks for that link, it will be really helpful it I can isolate it to the EPS motor, since the access to it is well defined and photo'd in the thread. I read through it, it seems like everyone who did the coupler piece change did it because of a rattle, not due to loss of EPS, but at least there's a well defined procedure for getting in there and getting my hands on the EPS motor.


I'll go through the service manual posted earlier as well and see if I can find an electrical spec for the motor (doesn't sound likely, since the poster couldn't find it) and I'll take home a bench power supply to see if I can test it outside the car under load.