2002 F250 SD, Crew Cab 4x4. Here is my issue, hopefully someone can shed some light. First issue, the ABS light flashes on my dash board almost constantly. Not really a big deal until the second issue. Second issue, when t he ABS light turns off on the dash, if I am in the process of braking at the exact moment the light turns off the brakes will "catch" and the truck will pull severely to the right. Not sure what's going on. Any help would be great. Thanks

 

Gotta get the codes read, but sounds like a front sensor is starting to go out.

It could be the wheel bearing itself is shot and the sensor isn't close enough to the tone ring.

CHECK IT ASAP.

 

wheel bearing is good, father in law ran the codes yesterday, couldn't get anything. (and he's a mechanic). Will double check though. Thanks

 

Not PCM codes, ABS codes. You need a CAN-capable reader to get the ABS codes.

If it pulls to the right, that means the ABS unit is releasing the LEFT side.

So, I'd check the wiring there (especially the connector for dirt/corrosion), pull the sensor and make sure the tip is clean.

I wouldn't go so far as to give you real numbers for the 2006, but if it was my 2001, I'd check the sensor voltage with a DVM (meter) in AC range, and make sure when spinning the wheel by hand it was somewhere above .350 volts. (350 millivolts)

There was a big "known issue" with the earlier Kelsey-Hayes ABS units in Chevy and Ford in the late 90's, and my 2001 has the same type of unit.

If the area under the ABS sensor rusted, it would push the sensor away from the tone ring, and cause low voltage from the sensor. So, the ABS unit would think the wheel had stopped spinning and activate the ABS for that wheel. In the Chevy TSB, they had the voltages necessary to get a good reading from the sensor.

In your case, I think the sensor is going bad, the ABS unit knows it (hence the blinking light) and sometimes, the sensor starts to work again, the ABS sees it back "online" and starts to use it. When it fails again, it thinks the wheel is locked up, releases that wheel, and causes the pull. So, if it's pulling right, it's the left sensor.

Of course, the ABS module itself might be going bad, but I bet it's the sensor itself, or there's enough crud under it, or it's coming loose, that the ABS module isn't seeing the correct voltage.

 

thanks krewat, I appreciate all your information. Will check everything out.