Anyone with the correct scanner can figure out which ABS sensor is not working correctly - one at each front hub and one on the rear axle housing.
Get that done at any good shop and then proceed from there. First have them check the connectors and wires for damage or loose... (do that yourself).
Nothing special about the Dynatrac front axle sensor replacement. If it is a front sensor the shop should be able to figure out the replacement part or get info through SMB West or Dyantrac.
Take sensor to Napa and let them find it for you.
Four time Baja 1000 winner, four time Baja 500 winner. Solo'ed the Baja 1000 to LaPaz/Cabo twice.
4-Wheeling since 1972, Desert Racing since 1989.