ELECTRIC POWER STEERING-ECU

The electric power steering-ECU is attached below the glove box, which is integrated with an input interface circuit, a microcomputer, an output drive circuit, a fail-safe relay, and a motor line relay. etc.
It is also integrated with a self-diagnostic function, and illuminates the warning lamp and outputs diagnosis code to the diagnostic connector.

CAN COMMUNICATION

The electric power steering-ECU performs the data transfer with another ECUs through CAN communication.

Signal	Receiver ECU
Signal	Engine-ECU <MT> or Engine-A-M/T-ECU <Automated manual transmission>	ABS-ECU or TCL/ASC-ECU	Electric power steering-ECU	Meter and A/C-ECU	ETACS-ECU
Motor current signal	·	-	-	-	-
Electric power steering warning lamp request signal	-	-	-	·	-

note

·: Performs the data transfer through CAN communication.

FAIL-SAFE FUNCTION

If the electric power steering-ECU detects any malfunction, it illuminates the warning lamp, deactivates the electric power steering function, and then switches the steering system into manual mode.

DIAGNOSTIC FUNCTION

Electric power steering-ECU has the following functions for easier system checks.

Diagnosis code set
Service data output
Actuator test

All the above items can be diagnosed using M.U.T.-III.

DIAGNOSIS CODE SET

There are 20 diagnostic items. Since all the diagnostic results are recorded in volatile memory (EEPROM*), they are stored in the memory even though the battery terminals are disconnected.

SERVICE DATA OUTPUT

Using M.U.T.-III, the input data sent from the sensors and motors can be read.