Hi, I'm having some issues with the ABS on my 2000 Bravada. It started out after going over a railroad crossing, I had an intermittent ABS light that would come in and out when going over bumps on the right side, as well as coming on when turning the wheel all the way to the right (full lock), and then would go away when letting off. Had the code read and it was the right sensor reporting erratically. Messed with the wire a bit and was able to get the light to come on and off by messing with where the wire kinks to go behind the dust shield, so I replaced the sensor as it was (all 3 shims, no cleanup etc).

New sensor has the over 15mph light issue. Light comes on and stays on until the car is turned off. That code is open circuit. Today I've been trial and error testing with cleaning the surfaces and removing shims. Removing 1-2 shims results in ABS engaging at low speeds ( below 5mph) but no trouble light. My thoughts on removing the shims were that the sensor is generating enough current to report to the ecbm but not give a proper reading at low speeds. I can't get my multimeter to display the voltage when I spin the wheels for some reason but resistance is showing about 1.05k ohms on both the old and new sensor so I believe it's functioning properly. I've searched around but it seems like people only have one of these scenerios, not all three. I'm kind of tired of pulling the caliper off so any help would be appreciated.

 

Just put all 3 shims back in and its still firing at low speeds with no lights. Think I may have gotten a bad sensor?

 

Replacing the sensor is not recommended, (for the very reason that you're experiencing). During the manufacturing process, each sensor is custom fit. If the sensor is in too far, it will contact the tone ring and be destroyed as soon as the vehicle moves. If the sensor is too far away from the tone ring, you'll either get low speed activation and no ABS light, or the ABS light will come on after the "rolling" self test. Best to replace the entire hub/bearing/sensor assembly. Just from your results, I'd say all of the shims need to be removed, BUT, you run the risk of destroying the sensor

 

it definitely hasn't touched yet, there are no marks or anything on the end of the sensor. would I be able to feel contact by rotating the hub by hand just to double check that I won't do any real damage from running without shims?

Will over voltage cause any weird behavior? Or do you think I'm at the point where as I said, it's generating enough voltage to pass the checks but not enough at low speeds causing the ABS to fire?

Tomorrow I'll check the old one vs the new one's length with calipers. I'd think that should at least give me an idea where I stand?

 

You might be able to feel it, no guarantees.


With both caliper pistons retracted, (to reduce drag) turning the wheel by hand, (one revolution per second) you should see at least 350 AC mV's. You'll need an accurate digital volt meter set to the AC millivolt scale, (not DC volts).


You'll need to accurately measure within .001"

 

I had the exact issue in my Bravada. I replaced the wheel bearings and that resolved everything.