Abs Does Not Operate Efficiently

CAUTION: If ABS/TRAC ECU replacement is necessary during testing, always ensure ABS/TRAC ECU connectors and ground circuit are okay. If either is suspect, repair and repeat testing to confirm ABS/TRAC ECU malfunction.

Retrieve Diagnostic Trouble Codes (DTC). See RETRIEVING DIAGNOSTIC TROUBLE CODES under DIAGNOSIS & TESTING. Check speed sensor circuits. See DTC 31-34: SPEED SENSOR CIRCUIT under DIAGNOSTIC TESTS. Check brakelight switch circuit. See BRAKELIGHT SWITCH CIRCUIT under COMPONENT TESTS. Check ABS/TRAC actuator. See ABS/TRAC ACTUATOR CHECK under COMPONENT TESTS. If ABS/TRAC actuator is okay, check hydraulic system for leaks. See Figure. If all listed items test okay, replace ABS/TRAC ECU.