Mitsubishi 380. Manual — part 879

COMBINATION METER ASSEMBLY

CHASSIS ELECTRICAL

54A-50

DIAGNOSIS

Required Special Tools:

• MB991958: Diagnostic Tool (MUT-III Sub Assembly)

• MB991824: Vehicles Communication Interface (V.C.I.)

• MB991827: MUT-III USB Cable

• MB991910: MUT-III Main Harness A (Vehicles with CAN

communication system)

STEP 1. Using diagnostic tool MB991958, diagnose the
CAN bus line.
Use diagnostic tool MB991958 to diagnose the CAN bus lines.
(1) Connect diagnostic tool MB991958 to the data link

connector.

(2) Turn the ignition switch to "ON" position.
(3) Diagnose the CAN bus line.

Q: Is the check result satisfactory?

YES : Go to Step 2.
NO : Repair the CAN bus lines. (Refer to GROUP 54C,

Diagnosis-Can Bus Diagnostic Chart

P.54C-405

).

STEP 2. Recheck for diagnostic trouble code.
Recheck if the DTC is set.

1. Erase the DTC.
2. Turn the ignition switch to "ON" position.
3. Check if the DTC is set.

Q: Is the check result satisfactory?

YES : An intermittent malfunction is suspected. Refer to

GROUP 00, How to Use Troubleshooting/Inspection
Service Points - How to Cope with Intermittent
Malfunction

P.00-14

.

NO : Replace combination meter.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

COMBINATION METER ASSEMBLY

CHASSIS ELECTRICAL

54A-51

DTC U1100: Engine ECU Time-out (Related to Engine) DTC U1101: Auto Transmission ECU Time-out
(Related to A/T)

CAUTION

If DTC U1100 or U1101 is set in the combination
meter, always diagnose the CAN bus lines.

CAUTION

Whenever the ECU is replaced, ensure that the
communication circuit is normal.

.

CIRCUIT OPERATION

Refer to

P.54A-49

.

.

DTC SET CONDITION

U1100

• The combination meter receives engine control

system-related signals from the Engine ECU via
CAN bus lines. If the display unit can not receives
the necessary signals, DTC U1100 will be set.

U1101

• The combination meter receives A/T control sys-

tem-related signal from the Auto Transmission
ECU via CAN bus lines. If the display unit can not
receive the necessary signals, DTC U1101 will be
set.

.

TECHNICAL DESCRIPTION (COMMENT)

CAUTION

If the ignition switch is turned to the ON position
without starting the engine, DTC (past trouble)
017 and 018 may be set on the combination
meter (incorporating meter-ECU) after three min-
utes.

Current trouble

• Connector(s) or wiring harness in the CAN bus

lines between the Engine ECU and the combina-
tion meter, the power supply system to the
Engine ECU, the Engine ECU itself, or the combi-
nation meter may be defective.

Past trouble

• Carry out diagnosis with particular emphasis on

connector(s) or wiring harness in the CAN bus
lines between the Engine ECU and the combina-
tion meter, and the power supply system to the
Engine ECU. For diagnosis procedures, refer to
"How to cope with past trouble" (Refer to GROUP
00, How to Use Troubleshooting/Inspection Ser-
vice Points

P.00-14

).

NOTE: For a past trouble, you may not find it by
the MUT-III CAN bus diagnostics even if there is
any failure in CAN bus lines. In this case, refer to
GROUP 00, How to Use Troubleshooting/Inspec-
tion Service Points

− How to Cope with Intermit-

tent Malfunction

P.00-14

.) and check the CAN

bus lines. You can narrow down the possible
cause of the trouble by referring to the DTC,
which is set regarding the CAN communica-
tion-linked ECUs (Refer to GROUP 54C, CAN
bus line Diagnostics Flow

P.54C-6

).

.

TROUBLESHOOTING HINTS

• Refer to circuit diagrams GROUP-

90

• Refer to configuration diagrams GROUP-

80

• The wiring harness or connectors may have

loose, corroded, or damaged terminals, or termi-
nals pushed back in the connector.

• Malfunction of Engine ECU.

• Malfunction of Auto Transmission ECU

• Malfunction of combination meter

16DB407A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

A/T

CONTROL

UNIT

COMBINATION METER ASSEMBLY

CHASSIS ELECTRICAL

54A-52

DIAGNOSIS

Required Special Tools:

• MB991958: Diagnostic Tool (MUT-III Sub Assembly)

• MB991824: Vehicle Communication Interface (V.C.I.)

• MB991827: MUT-III USB Cable

• MB991911: MUT-III Main Harness A (Vehicles with CAN

communication system)

STEP 1. Using diagnostic tool MB991958, diagnose the
CAN bus line.
Use diagnostic tool MB991958 to diagnose the CAN bus lines.
(1) Connect diagnostic tool MB991958 to the data link

connector.

(2) Turn the ignition switch to "ON" position.
(3) Diagnose the CAN bus line.

Q: Is the check result satisfactory?

YES : Go to Step 2.
NO : Repair the CAN bus lines (Refer to GROUP 54C,

Diagnosis-Can Bus Diagnostic Chart

P.54C-15

). On

completion, go to Step 6.

STEP 2. Using diagnostic tool MB991958, read the MPI
system diagnostic trouble code.
Check if an MPI system DTC is set.

Q: Is the DTC set?

YES : Diagnose the MPI system by referring to GROUP

13A, MPI Diagnosis

− Diagnostic Trouble Code Chart

P.13A-17

.

NO : Go to Step 3.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

COMBINATION METER ASSEMBLY

CHASSIS ELECTRICAL

54A-53

STEP 3. Using diagnostic tool MB991958, read the
diagnostic trouble code related to the other system.
Check if a DTC, which relates to CAN communication-linked
systems below, is set.
ABS-ECU

• DTC U1100: Engine ECU time-out (related to Engine)

<vehicles with TCL>

• DTC U1101: Auto Transmission ECU time-out (related

to automatic transmission) <vehicles with TCL>

Multi-centre display

• DTC 011: Engine ECU time-out (related to Engine)

• DTC 012: Auto Transmission ECU time-out (related to

A/T)

ETACS-ECU

• DTC 011: Engine ECU time-out (related to Engine)

• DTC 012: Auto Transmission ECU time-out (related to

A/T)

A/C-ECU

• DTC U1100: Engine ECU time-out (related to Engine)

Q: Is the DTC set?

YES : Go to Step 4.
NO : Go to Step 5.

STEP 4. Recheck for diagnostic trouble code.
Recheck if the DTC is set.

1. Erase the DTC.
2. Turn the ignition switch to "ON" position.
3. Check if the DTC is set.

Q: Is the check result satisfactory?

YES : A poor connection, open circuit or other intermittent

malfunction is present in the CAN bus lines between
the Engine ECU and the combination meter (Refer to
GROUP 00, How to Use Troubleshooting/Inspection
Service Points

− How to Cope with Intermittent

Malfunction

P.00-14

).

NO : Replace Engine ECU and then go to Step 6.

STEP 5. Recheck for diagnostic trouble code.
Recheck if the DTC is set.

1. Erase the DTC.
2. Turn the ignition switch to "ON" position.
3. Check if the DTC is set.

Q: Is the check result satisfactory?

YES : A poor connection, open circuit or other intermittent

malfunction is present in the CAN bus lines between
the Engine ECU and the combination meter (Refer to
GROUP 00, How to Use Troubleshooting/Inspection
Service Points

− How to Cope with Intermittent

Malfunction

P.00-14

).

NO : Replace combination meter and then go to Step 6.