Check The Power Source Circuit.

Disconnect the connector from the ABS control module.
Turn the ignition switch ON, measure the voltage between terminal 18 of the ABS control module harness side connector and body ground.
Specification: approximately B+

Is the voltage within specification?

YES
- Check the ground circuit.
NO
- Check the harness or connector between the fuse (10A) in the engine compartment junction block and the ABS control module. Repair if necessary.
Fig 1: Checking Harness Or Connector Between Fuse Engine Compartment Junction Block And ABS Control Module
Courtesy of KIA MOTORS AMERICA, INC.