Abs Does Not Operate Efficiently

WARNING: This page is about a different car, the 2000 Lexus SC 400, 2000 Lexus SC 300, 1999 Lexus SC 400, and 1999 Lexus SC 300. However, it is still accessible from the selected car via links, so may be relevant.

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.