Mitsubishi Outlander (2013+). Manual - part 172

ELECTRIC POWER STEERING

ELECTRIC POWER STEERING (EPS)

37-8

TORQUE SENSOR

M2370001600020

The torque sensor is mounted on the column shaft,
and detects the steering force. When the steering
wheel is turned, the phase relationship between the
input shaft and the lower shaft will be changed due to
distortion of the torsion bar. The torque sensor will
detect the distortion angle and send two voltage sig-
nals (main and sub) to the EPS-ECU in accordance
with it.

ELECTRIC POWER STEERING-ECU
(EPS-ECU)

M2370000800195

The EPS-ECU includes an input interface circuit, a
microprocessor, an output drive circuit, a power relay
and a motor line relay. It also integrates a self-diag-
nostic function, and illuminates the warning lamp on
the combination meter when a trouble occurs. At the
same time, it sends diagnosis code(s) to the diagno-
sis connector.

CAN communication

The EPS-ECU communicates with the other ECUs
and other units through CAN communication to con-
trol the steering system.

NOTE: Indicates items which send and receive data
through CAN communication.

ACB05508

Torque sensor

Lower shaft

Torsion bar

Torque sensor

Input shaft

Output voltage (V)

Torque sensor characteristic chart

Neutral

Sub

Main

2.5

Input signals

Sent to

Engine-ECU

4WD-ECU

Combination
meter (via the
ETACS-ECU)

ETACS-ECU

Engine speed

•

−

Vehicle speed

•

−

Additional torque

•

Distance information (diagnosis
additional information)

−

•

−

Vehicle information (diagnosis
control)

−

•

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ELECTRIC POWER STEERING

ELECTRIC POWER STEERING (EPS)

37-9

NOTE: Indicates items which send and receive data
through CAN communication.

Fail-safe function

If the EPS-ECU detects any malfunction, it illumi-
nates the EPS warning lamp, deactivates the EPS
functions, and then switches the steering system into
manual mode.

DIAGNOSIS FUNCTION

The EPS-ECU has the following functions to make
system checks easier.

• Diagnosis code set

• Service data output

All the above items can be diagnosed using MUT-III.

Diagnosis code set

There are 29 diagnostic items. Since all the diagnos-
tic results are recorded in volatile memory (EEP-
ROM*), they are stored in the memory even though
the battery terminals are disconnected.

NOTE:

•

*EEPROM (Electrical Erasable & Programmable
ROM): Special type of memory that can be pro-
grammed or erased electrically.

•

For diagnosis items, refer to Workshop Manual.

Service data output

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

NOTE: For service data items, refer to Workshop
Manual.

OPERATION

M2370000700217

IGNITION SWITCH ON

Ignition supply voltage is applied to the EPS-ECU,
and the ECU enters standby mode.

1. When the engine is started, the engine speed sig-

nal sent from the engine-ECU is input to the
EPS-ECU.

2. After starting the engine, the EPS-ECU judges

the engine status "ENGINE SPEED ON" when
the engine speed reaches 500 r/min, then the
power assist function is ready.

Output signal name

Received by

Engine-ECU

Combination meter
(via the ETACS-ECU)

Diagnosis connector

Motor current signal

•

−

EPS warning lamp illumination
request signal

−

•

−

Diagnosis code signal

−

•

Service data output signal

−

•

AC611649

Electric power
steering-ECU

Engine-ECU

OFF

Motor

Motor current signal

Maximum limit value (82Arms)

Engine speed

500 r/min

min 0.6 second

0.8 second

Motor output

Determination of motor
control start

Temporary increase of motor
assist limit value

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ELECTRIC POWER STEERING

ELECTRIC POWER STEERING (EPS)

37-10

STEERING WHEEL OPERATION

1. When the steering wheel is operated, the torque

sensor integrated into the column shaft detects
the steering torque and outputs the torque sensor
signal (main and sub), which varies with the
steering force, to the EPS-ECU.

2. The EPS-ECU outputs the current in proportion to

the torque sensor signal to the motor.

3. The motor outputs the rotational torque (assist

torque) in proportion to the current intensity and
assists the power steering gear.

FAIL-SAFE FUNCTION OPERATION

During the fail-safe mode, the electric power steering
operates as a manual steering system.

ACB05506

EPS-ECU

Torque sensor

Torque sensor signal (main)

Torque sensor signal (sub)

Motor current