Abs Does Not Operate
WARNING: This page is about a different car, the 1998 Lexus SC 400, 1998 Lexus SC 300, 1997 Lexus SC 400, and 1997 Lexus SC 300. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
If ECU replacement is necessary during testing, always ensure ECU connectors and ground circuit are okay. If either are suspect, repair and repeat testing to confirm ECU malfunction.
Retrieve Diagnostic Trouble Codes (DTC). See RETRIEVING TROUBLE CODES under SELF-DIAGNOSTIC SYSTEM. Ensure a normal code is output. Check ignition power supply circuit. See DTC 41 IGNITION POWER SOURCE CIRCUIT under SELF-DIAGNOSTIC SYSTEM. Check speed sensor circuits. See DTC 31, 32, 33 and 34 (speed sensor circuit codes) under SELF-DIAGNOSTIC SYSTEM . Check ABS/TRAC actuator. See appropriate ABS/TRAC ACTUATOR CHECK under DIAGNOSIS & TESTING . If ABS/TRAC actuator is okay, check hydraulic system for leaks. See Fig 1. If all listed items test okay, replace ABS/TRAC ECU.