ABS is coming on at low speeds?

2004 FORD F-150
150,000 MILES • 4.6L • V8 • 2WD • AUTOMATIC
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BOOTDOG54
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Hello, I'm a mechanic yet having trouble with an ABS problem. ABS pulsates at low speeds, right around 15 mph and lower. Rotors are good, ABS light was on, diagnosed and the problem lead to the ABS box /module. Changed out box/module and the light went out, yet it still pulsates at low speeds. I used diagnostic computer to monitor speed sensors and all numbers are normal and no codes are present. Any ideas? I think its a speed sensor but which one? I hope yall can help.
May 6, 2014 at 5:44 AM
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HMAC300
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This is caused by weak signal to the ABS module. I would check the sensors to see if they are dirty or corroded.
May 6, 2014 at 5:57 AM
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BOOTDOG54
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We're using a Bosch program on the laptop in real time it showed the right front seanr was weak so I got new one fixed it thanks for the help
May 6, 2014 at 6:27 AM
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JJB1960
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Well, i didn't see this 1 coming. Haven't done the rotors yet because after driving it on Wednesday and it sure felt like the problem was in the rear. So i pulled the drums of, and after comparing the hardware side to side, realized one of the springs, well both of these retaining springs were the same. So went to the store where i got them and wanted to look at a new hardware pkg. And sure enough they were the same. This is wrong because with them both the same, its hitting the emergency brake and causing it to bind up, which made the cable bind up and push the retainer thru the backing plate and binding everything up. So i think its safe to say that this was the problem all along, i hope. Had to go to work after discovering this and got snowed in in fair play, wait for my ride. Lol. But i had to bend the 1 spring around so it was a mirror to the other 1 and now it doesn't interfere with anything. Things you don't expect. Now i need a new emergency brake cable and then will know. Will keep you posted. Thanks.
Mar 13, 2021 at 5:26 PM
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JACOBANDNICKOLAS
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Hi,

We haven't heard from you for a few days. Have you made any progress? We are interested in knowing.

Joe
Mar 16, 2021 at 6:57 PM
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JJB1960
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After the deal with the emergency brake, yes i think i still have warped rotors. We got a couple feet of snow here and have not been working on the truck. I will let you know bout the rotors.
Mar 17, 2021 at 6:24 PM
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JACOBANDNICKOLAS
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Sounds good. Let us know when you get back to it.

Take care,
Joe
Mar 17, 2021 at 6:35 PM