System Operation
Self-Diagnosis FunctionABS control module diagnoses conditions of the system component parts (whether or not there is any abnormality) all the time and indicates the results (warning of abnormality occurrence and DTC) through the "ABS" warning lamp as described below.
1. When ignition switch is turned ON, "ABS" warning lamp lights for 2 seconds to check its bulb and circuit.
2. When no abnormality has been detected (the system is in good condition), "ABS" warning lamp turns OFF after 2 seconds.
3. When the vehicle starts to move after the ignition switch is turned ON (more than one wheel speed sensor signals are inputted), solenoid valves and motor of ABS hydraulic unit operate once one after another for electrical check. During this check, motor operation sound may be heard but that means nothing abnormal.
4. When an abnormality in the system is detected, "ABS" warning lamp lights and the area where that abnormality lies is stored in the memory of EEPROM in ABS control module.
5. When Diag. switch terminal of diagnosis connector (monitor connector) is grounded, the abnormal area is output as DTC. It is indicated by flashing of "ABS" warning lamp. For procedure to clear all DTC's, refer to the item How To Clear Diagnostic Trouble Codes.