Abs Does Not Operate Efficiently

Retrieve Diagnostic Trouble Codes (DTC). See RETRIEVING DIAGNOSTIC TROUBLE CODES  under DIAGNOSIS & TESTING. If any DTCs are present, perform appropriate diagnostic test. If no DTCs are present, check speed sensor circuit. Perform appropriate wheel speed sensor circuit test. See DIAGNOSTIC TROUBLE CODE IDENTIFICATION  table under DIAGNOSIS & TESTING. Check brakelight switch circuit. See DTC C1249/49: BRAKELIGHT SWITCH CIRCUIT  under DIAGNOSTIC TESTS. Check ABS/TRAC/VSC actuator. See ABS/TRAC/VSC ACTUATOR CHECK  under COMPONENT TESTS. If ABS/TRAC/VSC actuator is not okay, check hydraulic system for leakage.