Mitsubishi 380. Manual — part 882

COMBINATION METER ASSEMBLY

CHASSIS ELECTRICAL

54A-62

DTC U1112: SRS-ECU Time-out

CAUTION

If DTC U1112 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

The combination meter communicates with the
SRS-ECU through CAN bus lines. If it can not
receive all the necessary signals from the SRS-ECU,
DTC U1112 is set.

.

TECHNICAL DESCRIPTION (COMMENT)

Current trouble

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

lines between the SRS-ECU and the combination
meter, the power supply system to the SRS-ECU,
the SRS-ECU itself, or the combination 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 SRS-ECU and the combination
meter, and the power supply system to the
SRS-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 SRS-ECU

• Malfunction of combination meter

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)

COMBINATION METER ASSEMBLY

CHASSIS ELECTRICAL

54A-63

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 4.

STEP 2. Using diagnostic tool MB991958, read SRS
diagnostic trouble code.
Check that the SRS-ECU sets a DTC.

Q: Is the DTC set?

YES : Refer to GROUP 52B, Diagnosis-Diagnostic Trouble

Code Chart

P.52B-21

.

NO : Go to Step 3.

STEP 3. 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 lines between the
SRS-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 SRS-ECU and then go to step 4.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

COMBINATION METER ASSEMBLY

CHASSIS ELECTRICAL

54A-64

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 : The procedure is complete.
NO : Go to Step 1.

DTC U1120: Failure Information on Engine ECU (Related to Engine)

CAUTION

If DTC U1120 is set in the combination meter,
diagnose the CAN main bus line.

CAUTION

If DTC U1120 has been set, SWS related DTC 021
(U1128) is also set. After SWS has been diag-
nosed, don't forget to erase DTC 021 (U1128).

CAUTION

The engine control system- related DTC may be
set when DTC U1120 is set. (For details refer to
GROUP 00, Intersystem Affiliated DTC Reference
Table

P.00-17

.) Diagnose the engine control sys-

tem first when the engine control system- related
DTC is set.

.

CIRCUIT OPERATION

Refer to

P.54A-49

.

.

DTC SET CONDITION

The combination meter communicates with the
Engine ECU via CAN bus line. If failure information is
sent to the Engine ECU, DTC U1120 will be set.

.

TECHNICAL DESCRIPTION (COMMENT)

Current trouble

• The Engine ECU or the combination meter may

be defective.

Past trouble

• Carry out diagnosis with particular emphasis on

connector(s) or wiring harness between the
Engine ECU and the combination meter. For
diagnosis procedures, refer to "How to cope with
past trouble" (Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points

P.00-14

).

.

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 combination meter

DIAGNOSIS

Required Special Tools:

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

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

• MB991827: MUT-III USB Cable

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

communication system)

COMBINATION METER ASSEMBLY

CHASSIS ELECTRICAL

54A-65

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