Mitsubishi Outlander (2013+). Manual — part 54

ELECTRONICALLY CONTROLLED 4WD

REAR AXLE

27-11

Electronically controlled 4WD electric circuit diagram

4WD-ECU

M2270000500078

FUNCTION

The main functions of 4WD-ECU are as follows:

1. Communication function

• CAN communication with other ECUs (Engine

ECU, CVT-ECU, ABS/ASC-ECU, steering
wheel sensor, ETACS)

ACB05564

AC

Engine-ECU

Ignition switch(IG1)

Fusible link

Fusible link

ABS/ASC
-ECU

Combination meter

4WD switch

Electronic control
coupling solenoid

NOTE:The dashed line indicates CAN communication lines.

7.5 A

10 A

15 A

ETACS-ECU
(Fuse)

ETACS-ECU
(Fuse)

Diagnosis
connector

IG1
relay

4WD-ECU

ETACS-ECU

LCD

4WD ECO
4WD AUTO
4WD LOCK

CVT-ECU

Steering
wheel sensor

ELECTRONICALLY CONTROLLED 4WD

REAR AXLE

27-12

• Communication with drive mode switch: The

signal from the drive mode switch changes
the drive mode.

• Combination meter display: Drive mode is dis-

played.

2. Coupling control function

• Current output: Differential control function of

the electronic control coupling according to
the vehicle conditions

3. ECU self-diagnosis function

• Initial check: ROM check, relay check, etc.

• Recording function of diagnosis codes and

freeze frame data in case of failure

• System shutdown function after failure detec-

tion, "4WD-E" and "LOCK" indicator warning
and message indication on display

• Normal control: Malfunction of CPU power

supply, relay check, open or short circuit of
the I/O signal, abnormal CAN communication

FAIL-SAFE FUNCTION

FAILURE DETECTION

4WD-ECU performs the following checks at a timing
shown in the chart below. 4WD-ECU determines the
malfunction occurred when the failure detection con-
ditions are met, and it sets the diagnosis code and
executes the countermeasures for trouble. When the
failure resume conditions are met, ECU determines
the status is normal, and resumes the system.

Start-up (Initial check just after the ignition

switch is turned ON.)

1. CPU check

• Performs the ROM and RAM check.

2. Actuator check

• After CPU check has been completed, check

the driving voltage with the actuator relay
OFF.

Always (During ignition ON status other than ini-

tial check operation)

1. CPU check

• Performs CAN communication and interactive

check between CPUs.

2. Power supply check

• Monitors the CPU supply voltage and checks

if the voltage is within specifications.

3. Actuator check

• Checks if the actuator relay turns ON accord-

ing to the control.

• Compares the command current value from

CPU with the monitored current and checks if
they agree.

4. External wire connection check

• Checks if the input and output of each exter-

nal wire connection is open, shorted, or stuck.

NOTE: For the fail-safe specification, refer to Work-
shop Manual.

DIAGNOSTIC FUNCTION

4WD-ECU has the following functions for easier sys-
tem checks. All of the following items can be diag-
nosed using the M.U.T.-III.

• Diagnosis code set

• Service data output

• Actuator test

• Freeze frame data output

DIAGNOSIS CODE SET

Using M.U.T.-III, the diagnosis code (information of
failures generated in the electronically controlled
4WD system) can be read. When a failure occurs,
4WD-ECU sets the diagnosis code for that failure in
the nonvolatile memory (EEPROM*), so the recorded
information will not be erased even if the battery is
disconnected.

NOTE:

.

•

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

•

For the diagnosis code output items of the elec-
tronically controlled 4WD, refer to Workshop
Manual.

SERVICE DATA OUTPUT

Using M.U.T.-III, the data (input data from each ECU
and switch) used for control by the electronically con-
trolled 4WD system can be read.

NOTE: For each service data item, refer to Work-
shop Manual.

ACTUATOR TEST

M.U.T.-III can forcibly drive the actuators (electronic
control coupling solenoid and drive mode indicator)
controlled by the electronically controlled 4WD sys-
tem.

NOTE: For the actuator test specification, refer to
Workshop Manual.

FREEZE FRAME DATA OUTPUT

M.U.T.-III can read the freeze frame data (driving
conditions when the failure occurs) set when the
diagnosis code is detected.

NOTE: For freeze frame data items, refer to Work-
shop Manual.

ELECTRONICALLY CONTROLLED 4WD

REAR AXLE

27-13

4WD SWITCH

M2270001300011

The 4WD switch has been installed on the floor con-
sole. When the 4WD switch is operated with the igni-
tion switch ON, the drive mode can alternate 4WD
ECO, 4WD AUTO or 4WD LOCK.

ELECTRONIC CONTROL COUPLING

M2270000700072

FEATURES

The electronic control coupling realizes the highly
reliable 4WD system with lighter weight and simpler
construction.

CONSTRUCTION

The electronic control coupling is comprised of the
front housing, main clutch, main cam, ball, pilot cam,
armature, pilot clutch, rear housing, magnetic coil,
and shaft.

• The front housing is joined to the propeller shaft

and rotates along with the shaft.

• The main clutch and pilot clutch are assembled to

the front housing on the outer side and to the
shaft on the inner side (The pilot clutch is
installed via the pilot cam).

• The shaft is engaged via serrations with the drive

pinion of the rear differential.

AC505099AC

Main clutch

Pilot clutch

Armature

Ball

Main cam

Magnet coil

Front housing

Rear housing

Rear differential

Shaft

Drive pinion

Pilot cam

ELECTRONICALLY CONTROLLED 4WD

REAR AXLE

27-14

OPERATION

Coupling stops (2WD: Magnetic coil de-energized.)

The drive force from the transfer is transmitted to the
front housing connected to the propeller shaft. The
drive force is also transferred to the pilot clutch and
the outer side of the main clutch assembled to the
front housing. Because the pilot clutch and the main
clutch are not engaged with the magnetic coil
de-energized, the drive force is not transferred to the
shaft and the drive pinion of the rear differential.

AC505106AE

Main clutch

Shaft

Front housing

Propeller shaft

Pilot clutch

Drive pinion
(Rear differential)

Magnet coil