Joel

For the past couple months my power steering has been shutting off randomly. It usually happens in parking lots after making a turn. I will get an error on my DIC that says POWER STEERING and it just dies. If I shut my car off and restart it the power steering works fine. It has been happening much more frequently the past week. It happened 3 times today. What could this be caused by? My car has 48,000 miles on it so it's not covered by the warranty. Here are the basics on my car:

05 Cobalt Sedan
5 speed manual

Thank you in advance for any help.

Joel

HackAbuse

Mine does it occassionally when I have my sound system turned all the way up, so it's probably related to current draw. You may have a short somewhere.

fivepointohman

Stupid question but have you checked the serpentine belt?

HackAbuse

Power steering in cobalts is electronic, not hydraulic

06blackg85ss

iTrader: (1)

check the plug in the back left of the underhood fuse box... they can get loose with wheel hop and shitty roads... I had that problem for a little while myself and the connector was just loose

Joel

The comment about it having to do with current draw reminded me of something else. Lately the radio has been humming when on AM. If i press the brakes the humming changes pitch and/or makes a static noise. It does the same thing if I adjust the AC blower, or turn on the turn signal, pretty much any change in current draw causes it. I think I definitely have some sort of electrical problem, but how am I going to locate it? I'll try the connector on the fuse box first off. Thanks for the quick replies so far.

fivepointohman

I did not know that, thats great, man do i really trust that electric power steering? LOL... I have to take a closer look at my car i guess on that one.. sorry man!

Tomtwtwtw

If you're having problems all over like that, I'd get your battery and alternator tested to make sure one or the other isn't on its way out. The hot Arizona summers tend to take a toll on electrical systems.

Joel

The car is new though, it shouldn't be having problems already....that's the whole point of buying a new car. Where is the power steering unit located? I am thinking I've got a short somewhere most likely. It also seems that the power steering only fails when it's real hot outside, like yesterday when it failed four times, it was 112 degrees outside, and my car was sitting outside all day. Maybe the power steering unit is overheating or something. This sucks.

smartmlp

iTrader: (1)

The power steering unit will shut it self off if it overheats.

As the module, look under your dash. You should be able to see the unit in plain sight, its attached directly to the steering shaft.

Joel

Crazy, it's actually in the car. I'm so used to oldschool hydraulic power steering pumps. I'm gonna check it out, see if there are any loose connections or anything obvious.

stryder

ok question, joel do you have an interceptor? I just got one and when I hooked the 12v to the little pink wire from the stock boost guage all kinds of haywire **** happens, such as the power steering coming on the dic, and when i turn the key off the car stays running.

Tomtwtwtw

Key word being *shouldn't*. I'm more concerned with you saying your radio reception gets worse when you hit the brakes, adjust your a/c, etc. To me that sounds like your car isn't getting enough electrical current, but there's plenty of other stuff that it could be. Good luck finding the fix, though. Electrical problems suck.

LSCobaltlover05

This is from the manual:

"If you turn the steering wheel in either direction several times until it stops, or hold the steering wheel in the stopped position for an extended amount of time, you may notice a reduced amount of power steering assist."

Hope it helps.

Joel

No I don't have an interceptor. I have no aftermarket equipment on the car at all. There is an ipod charger/fm transmitter, but that can't be causing this i'm sure. As for the radio reception, it's only with AM, and it seems to be only when I'm on a weaker station that reception cuts out. I'm not sure if that's normal, or if it's in any way related to the power steering issue.

suburbanrobot

what if this happens on the highway while going around a curve?

Joel

My fiance asked me the same question. You can still turn the wheel, it's just a little difficult...

06G5GT

The same thing that would happen if you lost your hydraulic boost. It would still be steerable but require more effort.

Joel

Alright, I think I've narrowed down the problem. It is definitely related to heat. It never happens at night, and it happens the most when the car has been sitting in the hot sun all day. It has been around 115 degrees during the day here lately, and it is parked outside. What could be causing this? Do you think the power steering unit itself is overheating? Does anyone else have this problem? Anyone have any ideas? I really want to fix this myself because my warranty is expired.

Thanks!

Mikey851

I'll check out some electrical diagrams and see if I can come up with anything.

This is from Alldata: "The PSCM nor the EPS motor are designed to handle 58 amps continuously. The PSCM will go into overload protection mode to avoid system thermal damage. In this mode the PSCM will limit the amount of current commanded to the EPS motor which reduces steering assist levels."

The computer selects if it will enter overload protection mode based on the amount of amperage which is drawn. If I were you, and I was going to diagnose the system, I would wait for a hot day when this is happening and use an amp clamp to monitor how much amperage is being consumed while you turn the wheel back and forth. The system uses a brush type DC motor, and if the brushes are damaged or the motor is damaged at all it will draw too much current and the computer will limit it's output.

player_1

I'm having the same problem too,
my power steering pops up on my DIC and then I loose all power steering.
if I turn the car off and on, I get the power steering back.
it seems pretty random to me thou

Joel

Well today, before I started driving it I spun the wheel back and forth from lock to lock a few times to try to get the power steering to shut off. Nothing happened and it worked the whole way home. I did it again just now when I drove it, and it worked fine again. Usually on my drive home it fails about 3-4 times, so apparently it helps to turn the wheel before driving it. I don't understand why that's the case, but that's what seems to be going on. Freakin stupid electric power steering. I wish it was just hydraulic, then I might know how to fix it.

As for hooking up an amp meter to the motor, I don't have the tools or the time required to do that. So I might just be screwed. I may have to just drive with intermittent power steering until I graduate in May and actually have money. Do you guys think this would be an expensive problem to have a mechanic fix?

Tomtwtwtw

Maybe dumb question, but have you checked the power steering fuse? It almost sounds like there is a short somewhere causing this intermittent failure. I don't believe it's heat related, only because there are tons of other Cobalts in the same weather, and this is the first case I've seen. Perhaps you can have the dealer inspect it, and, depending on the cause, save yourself some money by fixing it yourself.

Joel

I've checked the fuse and it appears to be fine. Usually fuses cause something to stop working entirely. I guess the fuse could be messed up, but that doesn't explain why it works when I crank the wheel before driving it.

Mikey851

Well I think ^ is on the right track about a short. What I was referring to was a short in the motor or somewhere else. Turning the steering wheel from lock to lock could have an effect as there is a steering wheel torque sensor as well as a control module for the power steering.

The problem could lie in either of those two components, and on other cars with steering wheel position sensors you actually have to calibrate them by turning the wheel from lock to lock. It's possible that something is wrong in that area. I looked a little yesterday for some info on how to diagnose it and didn't get much help from "Some Data" lol; I will look again and let you know if I find anything.

Here is a picture of the circuit. Sorry for the size, I can't resize because I'm not at home right now. The blue dot is the motor, the green dot is the control module and the red dot is the steering torque sensor. If any one of those have a problem you will experience what you are experiencing. Your problem is intermittent, so it's probably going to be a connection issue somewhere. Like I said I will see what I can dig up:

[IMG][/IMG]