ABS Hydraulic Unit/Control Module Assembly Description

ABS Hydraulic Unit/Control Module Assembly Description
ABS control module is a component of ABS hydraulic unit/control module assembly and has the following functions.

Self-Diagnosis Function
ABS 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.
^ When ignition switch is turned ON, ABS warning lamp lights for 2 seconds to check its warning lamp and circuit.
^ When no abnormality has been detected (the system is in good condition), ABS warning lamp turns OFF after 2 seconds.
^ 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.





^ When Diag. switch PNK wire terminal (2) of blue diagnosis connector (1) (monitor connector) is grounded, the abnormal area is output as DTC. It is indicated by flashing of ABS warning lamp. (Refer to the following table.)








^ For procedure to clear all DTC's, refer to DTC Clearance. Clearing Trouble Codes
Also ABS control module turns ON EBD warning lamp (brake warning lamp) depending on the trouble that detected by the module and EBD warning lamp does not indicate DTC as well as ABS warning lamp.

Fail-Safe Function
When an abnormality occurs (an abnormal DTC is detected), ABS control module turns OFF the fail-safe relay (transistor) which supplies power to itself. Thus, with ABS not operating, brakes function just like the brake system of the vehicle without ABS.

Fail-Safe Operation
When ABS hydraulic unit/control module detects malfunction, when ABS hydraulic unit/control module enters fail-safe mode and ABS hydraulic unit/control module turns off ABS or EBD operation.

Fail-Safe Operation Table

Fail-Safe Operation Table: