Thread: Brake Pedal Vibration Issue

So I'm seeing something on my '06 Grand Prix that has me a little lost. I figured someone here has seen the issue, and can give me a little guidance. When I'm driving slow (5-15 mph), there is an odd noise that I believe is coming from my brakes. The best way I know to describe it is like similar to a deep grinding type noise. This still isn't really an accurate description, but it is an abnormal sound. From the driver's seat it sounds as if it's coming from the front driver's wheel. The more telling item may be that when this happens, the brake pedal pushes back at you and has a bad vibration. When it's happening, you don't have good brakes, but you can press through it and the brakes are there. I've noticed in parking lots and on driveways, both smooth and rough, but it may happen more often on rough surfaces with holes and such. When it happens, it does it for approximately 2-5 seconds then goes away. It will do it with or without you applying the brakes. I've had the pads changed about a year ago, and I had someone check the pads and rotors the other day with my oil change. He said all that looks good. It started as an occasional problem, but it is doing it more often. Does anyone have any ideas as to what may be going on?

Also check the wiring harness from the hub to the engine along the control arm. They corrode up and make intermittent connections activating the abs. An ABS code reader may help you diagnose before going full module rebuild.


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I agree with the above. I swapped out way too many abs parts before I realized it was the actual pins on the abs connector had corroded. Probably not the issue on yours as Markpa stated, the wiring tends to go bad or short. ABS scanner is your best freind.

If the ABS light hasn't come on, would it still show an error code once connected to a scanner? Also, would the code readers they use at Autozone or Advance have the capability to read these codes?

A very very common issue on the 99-03 is a fault in the module. It's happening on mine right now. Basically, the module doesn't talk to the car all the time or ever m even scan tools so it won't throw any codes 99% of the time even though they're there. Only fix is to either replace or ship to some guy on eBay that repairs them. I'm about to try repairing myself since all it is is a quick solder with really thin wire. Only problem is that it's EXTREMELY precise work so you need a precise adjustable soldering iron with temp control and a magnifying glass with a very steady hand. I've done precision soldering before so I'll keep you posted!

I believe I have confirmed that it's on the ABS system. I pulled the ABS fuse (#23 if anyone was wondering), and I have yet to have it happen. Normally I can't make it out of my drive without it occurring 3-4 times, but I've made 4 trips in and out with no issue. Now I just need to get it somewhere with an ABS capable code reader.

If it turns out to be the control module, it looks like they are fairly expensive. Would it be ill advised to find one on a you pull it type junkyard? I know it likely wouldn't last as long as having mine repaired or purchasing a new one, but it would save a good deal of money. If I go that route, would the control modules on similar year Impalas and Malibus be the same?

On a side note, I appreciate the advise/help with this issue. I'm already further much along in diagnosing the problem than I was before.

Or keep the fused pulled. My 08 does not have anti lock brakes. Actually stops quicker when you jump on it.


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Can also be a bad wheel speed sensor with one of the speed signals dropping out at low speeds. My ol 98 Regal had bad rear bearing and my newest Wbody, an 04 Grand Prix needs new right front hub bearing assembly. when I do it I have a pair of rear bearings Ill install. Also I am planning to install brakes soon too.
If the ABS connector is corroded fix that issue or disable it. If its ok a reasonable dollop of dielectric grease will eliminate it happening. If your not getting a light my thought would be hub bearing first, but a scan while its activating will confirm.