ABS System Diagnosis Cost
ABS control module failures can set diagnostic codes for wheel speed sensors, ABS pump motors, and other ABS system parts. Replacing those items will not address the problem and repair or replacement of the ABS control module will still be required.
As part of an ABS system diagnosis, the wheel speed sensors should be checked for looseness and dirt. Sometimes securing a loose sensor and/or cleaning the wheel speed sensors will address the ABS issue.
Just like your computer at home, the ABS system may need occasional software upgrades to address various issues. A quality shop will check with the vehicle manufacturer for any Technical Service Bulletins (TSBs) related to the problems you're having and will upgrade the software when possible.
A malfunctioning ABS system can cause the ABS, traction control, brake, and possibly the Check Engine lights to illuminate. Speedometer operation may stop as well.