False ABS Activation
07-15-2008, 07:53 PM
#1
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Join Date: Jul 2008
Location: Connecticut
Posts: 1,140
False ABS Activation
Hello everyone, I am new. Nice to meet all you fellow 4.6'rs
You might want to turn up your sound a little bit but this is basically a video of my car with a friend of mine recording as we drive around at low speed of about >10mph. There is a buzzing noise, and the buzzing is when I press the brake pedal normally to come to a controlled stop, and it occurs during the controlled 5-0mph stop. The buzzing is most certainly a false ABS activation, and some have said that the wheel speed sensor might be clogged and getting a strange reading. The pedal vibrates by the way when the buzzing is going on.
The clicking that follows the buzzing does not usually happen. I am able to get it to come on because I know how to make it happen after dealing with the problem for so long. It comes from when I am on either inclined.. or flat surface.. and I come to a very drawn out slowww.. extremely calm stop. I can hit the brake pedal.. hear the buzz, then take my foot off the brake pedal and cruise at like 3 mph.. and it will click like that. One time, I went across a slight incline with it clicking like that for 15 seconds or so.. now that was abnormal.
So anyway.. here’s the video.
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You might want to turn up your sound a little bit but this is basically a video of my car with a friend of mine recording as we drive around at low speed of about >10mph. There is a buzzing noise, and the buzzing is when I press the brake pedal normally to come to a controlled stop, and it occurs during the controlled 5-0mph stop. The buzzing is most certainly a false ABS activation, and some have said that the wheel speed sensor might be clogged and getting a strange reading. The pedal vibrates by the way when the buzzing is going on.
The clicking that follows the buzzing does not usually happen. I am able to get it to come on because I know how to make it happen after dealing with the problem for so long. It comes from when I am on either inclined.. or flat surface.. and I come to a very drawn out slowww.. extremely calm stop. I can hit the brake pedal.. hear the buzz, then take my foot off the brake pedal and cruise at like 3 mph.. and it will click like that. One time, I went across a slight incline with it clicking like that for 15 seconds or so.. now that was abnormal.
So anyway.. here’s the video.
<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/qbbJCe4Il8g&hl=en&fs=1"></param><param name="allowFullScreen" value="true"></param><embed src="http://www.youtube.com/v/qbbJCe4Il8g&hl=en&fs=1" type="application/x-shockwave-flash" allowfullscreen="true" width="425" height="344"></embed></object>
07-15-2008, 07:54 PM
#2
4th Gear Member
Thread Starter
Join Date: Jul 2008
Location: Connecticut
Posts: 1,140
07-15-2008, 09:25 PM
#6
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Join Date: Jul 2008
Location: Connecticut
Posts: 1,140
RE: False ABS Activation
I know the speed sensors are in by one bolt.. I just havent found the time to jack up the car and get the proper leverage to unbolt them and take them out and see whats up.
07-15-2008, 10:12 PM
#7
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Join Date: Oct 2006
Location: Durham, NC
Posts: 1,541
RE: False ABS Activation
Do you have an ABS light on? Do you know if its been disconnected or unplugged? Have you had to refill the master cylinder any? You can pull trouble codes to determine where in the system the fault is originating. If its not throwing codes, then the reluctor ring or sensor is bad. Im no where near a shop manual, but to test the sensor/ring you need a multimeter. Sensor checks are as easy as measuring the ohmspresent by the sensor. To test the rings, switch it to volts and measure the output after the sensor, spin the wheel as fast as possible and you should get a value. Again, i do not know what these values should be...but i'm sure any large discrepancy should be the faulty ring/sensor.
As for the clicking...i have no idea.
As for the clicking...i have no idea.
07-15-2008, 10:28 PM
#8
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Join Date: Jul 2008
Location: Connecticut
Posts: 1,140
RE: False ABS Activation
There is no ABS light on.
I unplugged the ABS fuse once, and the light came on. The vibration stopped. I plugged in the fuse, and the ABS light went away and the vibration came back.
I changed the brake fluid about 5 months ago.
I never pulled any kind of codes.
I can get the car to do that clicking while at a slight roll, in neutral for like, 30 seconds. In fact, I just did it about an hour ago.. I was just testing it. My friend was in the car, stuck his head out the window and said he could hear the clicking up front, from the front right wheel. I made it click for a longgggg time, then I finally released the brake fully and it went away completely.
I unplugged the ABS fuse once, and the light came on. The vibration stopped. I plugged in the fuse, and the ABS light went away and the vibration came back.
I changed the brake fluid about 5 months ago.
I never pulled any kind of codes.
I can get the car to do that clicking while at a slight roll, in neutral for like, 30 seconds. In fact, I just did it about an hour ago.. I was just testing it. My friend was in the car, stuck his head out the window and said he could hear the clicking up front, from the front right wheel. I made it click for a longgggg time, then I finally released the brake fully and it went away completely.
