My ABS Inop light recently started coming on intermittently. any ideas what is causing this??

 

Check your third brake light in the rear, if the bulb is slowly burning out the abs light will come on and off depends if the light is completely burned out or not. its happend to me.

another reason might be low battery voltage, or a problem with the VSS. see if you can pull the abs code out and you can go from there.