Mitsubishi Outlander (2013+). Manual — part 718

EXPLANATION ABOUT THE M.U.T.-III CAN BUS DIAGNOSTICS

CONTROLLER AREA NETWORK (CAN)

54C-8

CAN BUS LINE DIAGNOSTIC FLOW

ACB05636

NG

AB

From other diagnosis

1. M.U.T.-III CAN bus diagnostics

Go to ordinary diagnosis

OK:
P code, B code,
C code or
U code (current trouble)

OK:
U code (past trouble)

2. Pinpoint possible trouble spot
according to diagnosis code

· Short between CAN bus lines.
· Short in CAN bus line to power
supply or earth.
· Open circuit in can bus line
· Broken terminator resistor
· Power supply to ECU poorly
earthed

·

Checking the communication condition of ECUs.

1. M.U.T.-III CAN bus diagnostics

The M.U.T.-III diagnoses CAN bus lines in
accordance with the following strategy.

• Checking the communication condition of ECUs

The M.U.T.-III narrows down troubles in circuit by

itself. Its strategies are as follows.

AC502594AB

Diagnosis
connector

ECU B

ECU C

ECU D

ECU A

(a)

(b)

(c)

(d)

(e)

(f)

(g)

Reference circuit

EXPLANATION ABOUT THE M.U.T.-III CAN BUS DIAGNOSTICS

CONTROLLER AREA NETWORK (CAN)

54C-9

ECU which
cannot
communicate
with the
M.U.T.-III

Possible
trouble spot

Logic for narrowing down trouble spot

ECU A

CAN bus line
(a) and power
supply system
to ECU A

ECU A communicates with
the M.U.T.-III via CAN bus
lines (a) and (b). The
M.U.T.-III judges that CAN
bus line (b) is normal,
because it can communicate
with other ECUs. Possible
trouble may be present in
CAN bus line (a) or the power
supply system to ECU A.

AC204742 AZ

Diagnosis
connector

ECU B

ECU C

ECU D

ECU A

(a)

(b)

(c)

(d)

(e)

(f)

(g)

ECU C

CAN bus line
(g) and power
supply system
to ECU C

ECU C communicates with
the M.U.T.-III via CAN bus
lines (b), (c), (d) and (g). The
M.U.T.-III judges that CAN
bus lines (b), (c) and (d) are
normal, because it can
communicate with ECUs B
and D. Possible trouble may
be present in CAN bus line (g)
or the power supply system to
ECU C.

AC204742 BA

ECU B

ECU C

ECU D

ECU A

(a)

(b)

(c)

(d)

(e)

(f)

(g)

Diagnosis
connector

ECU C and
ECU D

Trouble in
CAN bus line
(d)

ECUs C ad D communicate
with the M.U.T.-III via CAN
bus lines (b), (c), (d), (e) and
(g). The M.U.T.-III judges that
CAN bus lines (b) and (c) are
normal, because it can
communicate with ECU B.
Possible trouble may be
present in CAN bus line (d),
(e) or (g) or the power supply
system to ECU D or C. CAN
bus line (d) is shared by ECUs
C and D when they
communicate with the
M.U.T.-III, so CAN bus line (d)
is suspected as ultimate
cause. CAN bus line (g) or (e)
and power supply systems to
ECU C or D are also
suspected as second cause.

AC204742BB

ECU B

ECU C

ECU D

ECU A

(a)

(b)

(c)

(d)

(e)

(f)

(g)

Diagnosis
connector

EXPLANATION ABOUT THE M.U.T.-III CAN BUS DIAGNOSTICS

CONTROLLER AREA NETWORK (CAN)

54C-10

2. If diagnosis code related to CAN communication

is set as past trouble, isolate opens as described
below.

NOTE: If you pinpoint trouble spot according to
diagnosis code, you should use time-out diagno-
sis code. diagnosis code related to failure infor-
mation is set when the data to be set contains an
error, so CAN bus line itself is probably normal.

NOTE: Time-out diagnosis codes are stored in
each ECU memory individually. Therefore, it is
possible that these diagnosis codes have not
been set simultaneously. If the trouble spot cannot
be found when you diagnose by judging from mul-
tiple diagnosis codes, check the communication
lines between each ECU.

ECU B and
ECU D

CAN bus line
(e) or (f) or
power supply
system to ECU
B or D

ECUs B ad D communicate
with the M.U.T.-III via CAN
bus lines (b), (c), (d), (e) and
(f). The M.U.T.-III judges that
CAN bus lines (b), (c) and (d)
are normal, because it can
communicate with ECU C.
Possible trouble may be
present in CAN bus line (f) or
(e) or the power supply
system to ECU B or D.

AC204742 BC

ECU B

ECU C

ECU D

ECU A

(a)

(b)

(c)

(d)

(e)

(f)

(g)

Diagnosis
connector

ECU which
cannot
communicate
with the
M.U.T.-III

Possible
trouble spot

Logic for narrowing down trouble spot

Diagnosis
code to be set

Possible
trouble spot

Logic for narrowing down trouble spot

Time-out
diagnosis code
associated with
ECU D is stored
in ECU A, ECU
B and ECU C.

Trouble in
CAN bus line
(e) and power
supply system
to ECU D

When time-out diagnosis code
associated with ECU D is stored
in ECU A, B and C, or time-out
diagnosis code associated with
ECUs A, B and C is stored in
ECU D, CAN bus line (e) is
suspected. When diagnosis code
is not stored in ECU D, the power
supply to ECU D is suspected.

AC204742 BD

ECU B

ECU C

ECU D

ECU A

(a)

(b)

(c)

(d)

(e)

(f)

(g)

Diagnosis
connector

Time-out
diagnosis code
associated with
ECUs A, B, C
and D is stored
in ECU.

Time-out
diagnosis code
associated with
ECU A is stored
in ECUs B, C
and D.

Trouble in
CAN bus line
(a) or (c) and
power supply
system to ECU
A.

When time-out diagnosis code
associated with ECU A is stored
in ECUs B, C and D, or time-out
diagnosis code associated with
ECUs B, C and D is stored in
ECU A, CAN bus line (a) or (c) is
suspected. When diagnosis code
is not stored in ECU A, the power
supply to ECU A is suspected.

AC204742 BF

ECU B

ECU C

ECU D

ECU A

(a)

(b)

(c)

(d)

(e)

(f)

(g)

Diagnosis
connector

Time-out
diagnosis code
associated with
ECUs B, C and
D is stored in
ECU A.

TROUBLESHOOTING

CONTROLLER AREA NETWORK (CAN)

54C-11

TROUBLESHOOTING

CAN BUS DIAGNOSTICS TABLE

M1548300202675

CAUTION

During diagnosis, a diagnosis code associated with another system may be set when the ignition
switch is turned on with connector(s) disconnected. After completing the repair, confirm all systems
for diagnosis code(s). If diagnosis code(s) are set, erase them all.

This diagnosis applies only to the CAN bus lines. If a
different system is defective, proceed to the applica-
ble diagnosis section for each system. Observe the
diagnosis procedure below only when the CAN bus
line is defective.

Time-out
diagnosis codes
associated with
ECUs C and D
are stored in
ECU A and
ECU B.

Trouble in
CAN bus line
(d)

If time-out diagnosis codes
associated with ECUs C and D
are stored in ECUs A and B, or
time-out codes associated with
ECUs A and B are stored in
ECUs C and D, CAN bus line (d)
is suspected. CAN bus line (g) or
(e) and power supply systems to
ECU C or D are also suspected
as second cause.

AC204742BQ

ECU B

ECU C

ECU D

ECU A

(a)

(b)

(c)

(d)

(e)

(f)

(g)

Diagnosis
connector

Time-out
diagnosis codes
associated with
ECUs A and B
are stored in
ECU C and
ECU D.

Diagnosis
code to be set

Possible
trouble spot

Logic for narrowing down trouble spot

M.U.T.-III screen

Diagnosis detail

Reference
page

(The ECUs that are not adopted are not
displayed.)

Comment

ACC00029

ACC00029

ACC00029

M.U.T.

: Red section on screen

JC

ETACS

KOS

AUDIO

SRS

OSS

ABS/ASC

CVT

ENGINE

EPS

SAS

AWC

MMCS

A/C

ETG

METER

Corner

JC

JC

AC

Failure in red
displayed area is
estimated.

Diagnosis Item 1
Communication with no
ECUs is possible
(CAN-C).

P.54C-17

−

−

Diagnosis Item 2

*1

Diagnose shorts in the
power supply to CAN-C.

P.54C-18