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Discussion Starter · #1 ·
Hey all. I just changed front pads and rotors on my daughters 2010. The ABS light was on when I backed out of the garage, and the TC light came on at the end of the driveway. After driving about 1/2 a mile both lights went out. When I stopped, the brakes “stuttered” a bit then the lights came on again and brakes felt fine. Again after 1/2 mile the lights went out. Any suggestions? Thanks.
 

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Define "stuttered". Both the ABS and TC work off the sensors at each wheel. If a wheel stops turning while the others are rotating it interprets that as a skid. The ABS then pumps the brakes at that wheel rapidly to stop the skid. Could that be the "stuttering"? Could you have gotten grease/oil/brake fluid on the brakes and they grabbed/"stuttered" when stopping? That could be interpreted as a skid too. The light would go out if the problem ceased.
 

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Discussion Starter · #3 ·
Stutter, just like when trying to stop on ice, but very quick. On dry pavement. I did check the rotors fo oil or grease, and nothingThinking it might be in the ABS control module, maybe some dirt or something. Thanks for the suggestions.
 

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Stutter, just like when trying to stop on ice, but very quick.
So it felt like the ABS was working but on dry pavement? That is very unusual. Again, it takes a stopped wheel sensor to enable ABS. Or it "thinks" the ABS sensor is stopped.
Well, with hard codes the ABS/TC would stay lit. Something like a bad/broken sensor, wire, or a bad module. So since the light went out on it's own it was an intermittent problem perhaps caused by something that happened during the brake job. Maybe check the wiring that goes into the wheel sensor and any connectors. It is fragile and could have been damaged or strained.
 

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Discussion Starter · #7 ·
So it felt like the ABS was working but on dry pavement? That is very unusual. Again, it takes a stopped wheel sensor to enable ABS. Or it "thinks" the ABS sensor is stopped.
Well, with hard codes the ABS/TC would stay lit. Something like a bad/broken sensor, wire, or a bad module. So since the light went out on it's own it was an intermittent problem perhaps caused by something that happened during the brake job. Maybe check the wiring that goes into the wheel sensor and any connectors. It is fragile and could have been damaged or strained.
Thanks, I’ll go over it all again.
 

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Did you happen to disturb the wheel speed sensor wires? Really shouldn’t be a problem when doing a brake job. More likely to happen when replacing struts or control arms. But if the wires were damaged by stretching or knocked by a tool, they may cause a malfunction.

A bad wheel hub assembly can cause such a problem. Usually happens when the bearing is failing and causing the tone ring inside to be mis-positioned. It’s highly unlikely. But sometimes if you have beat the brake rotors off the car, to replace or machine, you can disturb the bearing if they’re older assemblies. I have a lot of cars come in for abs problems that turn out to be a bad hub assembly. The sensors are occasionally bad on GMs, but this is an older car. I just had a Jeep in with 37,000 miles that already had a failed wheel speed sensor. It was causing the abs to activate and not allow the vehicle to quickly accelerate. Causing the customer to be afraid to drive it very far.

On the Jeep, and also our Cobalts, the abs sensing wheel speed differences will active the abs pump and also can cause the throttle go “dead”. Like you may push the accelerator to the floor and it will not respond. I’m sure you have experienced this while driving in snow or ice where you’re from. Also can happen in mud or sand. Really anywhere the wheels are losing traction. But when a sensor is malfunction be cause of a bad sensor, wire or hub assembly, it can cause unwanted actuation of the abs and traction control systems.
 

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I have done four wheel hubs this year on our cars. One on a 2012 Jeep, and one on our '08 Cobalt. The Cobalt did not have ABS but the hub was howling at highway speed. The 2012 Jeep was the only one with ABS and it was an ABS code that led to discovering the bad hub. I remember on that Jeep that the ABS wire was clipped to the brake hose. To remove the caliper it needed to be unclipped from the brake hose. Easy to see it getting twisted or pulled.
 

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I was remembering the ABS wires on my car. And they don’t look too good. The outer wire casing is flaking apart. But they do work ok. Although my ABS pump is not currently working. One of a few things I plan to fix at some point.

Honestly most of my cars have had faulty ABS since they’ve all been older vehicles. My first two cars didn’t even come with ABS though so I really don’t need it too bad, 70s and 80s cars. It’s nice to have when it’s necessary though. My traction control works on this Cobalt and I do like that it does. That means the wheel speed sensors are working. Traction control on the Cobalt works by altering the throttle body position and reducing power when the tires slip.

I don’t know if the code readers that places like O’Reillys or AutoZone have will read stores codes for ABS. They may only read codes if they light is illuminated. Either way they will read your codes for free, so that’s something you may consider trying. I guess it couldn’t hurt to go by the store and ask. Not sure if y’all have those auto parts stores up there in Canada or not. I know AutoZone is in other countries besides the US. I know for sure they have them in Mexico. Although I never saw one down there.
 
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