couple issues...might be related?

MomsAlero · 08-20-2011, 07:01 AM

on my mom's 01 Alero 4dr with the 2.4/auto, there are a few issues...I have some ideas as to what They could be but I'd rather ask the "pros" so I could know for sure without throwing parts at it.

first problem I can't simulate, but my mom swears is happening. she says every now and then when she uses the brakes there's a vibration (sounds like a warped rotor but its not happening all the time). but I've driven the car twice now and cannot simulate this.

second problem I know exists...sometimes when you turn the wheel to the left or right, the "Trac Off", "ABS" and "Service Vehicle Soon" light come on.

my ideas on this are possibly a bad wheel bearing (but its not making any noise) or a bad ABS sensor or wiring...haven't pulled wheels yet to look...any help at all would be greatly appreciated!!

MMGT1 · 08-20-2011, 08:47 AM

Sounds like you got it man. Id say a bad hub

a.graham52 · 08-20-2011, 09:02 AM

id check the wires first and makse sure they havnt rubed anywhere. then jack the wheels and make sure theres no play in the hubs and go form there. as for your brakes try making a stop from 50-10 going down hill. that should warm them up pretty good. driving styles really make a difference with brakes. you could be a lot more gentle with them and therefore they dont heat up enough to cause a pulse.

Redog · 08-20-2011, 09:50 AM

Yes it's def a wheel hub you have there, but you'll have to get it scaned to find out which one, then play around with the wires and bearing itself BEFORE replacing the hub.

Since it's not constant, could be a loose connection. I'd hate to see anybody put money were it isn't needed

MMGT1 · 08-20-2011, 09:51 AM

Agree 100% with Red there^^

MomsAlero · 08-20-2011, 10:31 AM

thanks for all the help y'all! I thought it was a hub or wiring, I just wanted To make certain. who can scan it to find out which one? I tried having Advance Auto Parts scan it and it came up with nothing since the Service Engine Soon light wasn't on, the Service VEHICLE Soon light was on...

Redog · 08-20-2011, 11:20 AM

You'll need a place that does ABS and body codes. Some Advance Autos have them, most don't. Call around

MomsAlero · 08-20-2011, 12:33 PM

well where would you say are some places to call to? like oil change places, places like Midas or Meineke? none of the auto parts stores here will run those kind of codes

TdotAlero · 08-20-2011, 05:27 PM

I had the same issue last winter. The three lights were always on and I was thinking it's the hub again, so I'll just replace it in spring. When I was swapping my winter tires to summer, I unplugged both front ABS sensors, and blew them with some air and cleaned the connection. The lights haven't come on since.
As for the first problem, it might be related to the bad bearing. If any of the front suspension parts are loose or broken, vibration will always be there. Or get the rotors machined, as a first option, as it's usually pretty cheap.

SIUlero · 08-20-2011, 06:29 PM

The pulsation she's feeling is most likely the ABS pump kicking in because of faulty readings from the wheel speed sensor. It will only do it when the SVS, ABS and Trac light are not on, so if those come on before you can reproduce the symptom, you'll have to restart the car. With the radio off, you should be able to hear the ABS pump running when you feel the pedal pulsate. Also, try turning the wheel a little while braking if you can't get it to do it straight-line.

Like others have said, check your wiring first, and if that's all good, figure out which sensor it is and replace that hub.

MomsAlero · 08-21-2011, 05:44 PM

ok guys, a little update. i took it to a place to get it scanned, popped the codes for BOTH front ABS sensors and a "open circuit" on the left side. so, i replaced the left side (i've heard of these cars having one side go out and causing the other side to freak and indicate it's bad too-and since i had two codes for the left, i replaced it). i pulled the left bearing out and sure enough, the ABS wires were broken...both of them. so i put in the new left bearing and now i'm waiting for the shop to open to reset the codes...then we'll see if i'm doing the right side too...

thanks for the help all, i really appreciate it!

oh, and one edit...the pulsation was the ABS trying to work. i finally was able to "feel" it. that's what i told her i thought it was...

MomsAlero · 08-26-2011, 07:10 PM

ok a little update, and its not really a good one. went today to have the codes cleared...the right side isn't coming on anymore...the left side (that I replaced) is coming on and as soon as you clear it it comes right back. I don't know if I got a bad hub or if maybe there's some bad wiring in there...but its not saying open circuit anymore, Just a bad wheel sensor...any ideas?

a.graham52 · 08-26-2011, 07:15 PM

whats the dtc number? always write those down for reference if you havnt already. check and double check the connector. make sure both terminals in the connectors arnt pushed out the back of the connector. also make sure the wires coming out of the sensor havnt rubbed on the cv joint.

MomsAlero · 08-27-2011, 02:30 AM

i'll have to go back and get the code ran one more time to know the DTC number. i forgot to get it...D'OH! i'll go over and over the wiring again and see if i missed anything...i wonder if i just got a bad sensor...