2001 Chevy truck 4wd ABS problem

Truck is going into ABS stop mode at slow speed intermittenly. My original thought was a lazy wheel speed sensor. When hooked to the scanner the wheel speed sensors are showing 3mph even at a dead stop / Transmission in Park. When driving wheel speed sensors are reading properly until you stop, then the lowest they read is 3mph. When the ABS system comes on all sensors go from what ever they are reading to 3mph. I am leaning towards a bad ABS module but was wondering if anyone else has had a similar issue. I dont see any tests procedures on the scanner and my vantage is not updated enough. Any thoughts? Thanks

What scanner are you using? My own snap on scanner does similar things even when the vhicle is stationary! I think you'll probably find you have tone rings that are rustted up and throwing the air gap off, very common on Gm truck and Ford Truck. My own opinion is that if the module talks and all 4 are reading equally it isn't the module

I am using a snap-on mt2500. I checked a bit further and found that the 3mph reading is common on this GM. I pulled the sensors and cleaned them already but I will try it again and look for play in a bearing. I was thrown a bit by the 3mph. Every other one I have done you could see the wheel that was acting up when it went into the abs mode. I guess they cant all be easy. Thanks for the input

I had a Grandam last week that continued with a lh rear speed sensor fault even with a new sensor an all 4 sensors read equally for speed on the road test. It had corroded wires in a pass through connector in the trunk floor. 24 ohms resistance on the drivers side, 2 ohms on the pass side. Like I said all 4 still rear equally with my MT2500. Did I see you with this truck on IATN?

Call the dealership with your VIN#.

I have a 2002 Silverado 4X4 and it was covered under a recall.

3 mph is normal for a GM when the vehicle is not moving. You probably have a speed sensor dropping out from either to much air gap or a dirty or loose ring. Unless you have a scope or something to graph the sensors it will be difficult to find. If it has any aftermarket front hub assemblies lately then I would suspect which ever one it was.