Mitsubishi Galant (2004+). Manual — part 1457

COMBINATION METER ASSEMBLY AND VEHICLE SPEED SENSOR

TSB Revision

CHASSIS ELECTRICAL

54A-71

STEP 1. Using scan tool MB991958, diagnose the CAN bus
line.
Use scan tool MB991958 to diagnose the CAN bus lines.
(1) Connect scan 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-14

). On

completion, go to Step 4.

STEP 2. Using scan 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-33

.

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.00-6

).

NO : Replace SRS-ECU and then go to step 4.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

COMBINATION METER ASSEMBLY AND VEHICLE SPEED SENSOR

TSB Revision

CHASSIS ELECTRICAL

54A-72

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 Powertrain Control Module (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
is also set. After SWS has been diagnosed, don't
forget to erase DTC 021.

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.00-16

.) Diagnose the engine control sys-

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

.

CIRCUIT OPERATION
Refer to

P.54A-57

.

.

DTC SET CONDITION
The combination meter communicates with the
powertrain control module via CAN bus line. If failure
information is sent to the powertrain control module,
DTC U1120 will be set.

.

TECHNICAL DESCRIPTION (COMMENT)

Current trouble

• The powertrain control module or the combina-

tion meter may be defective.

Past trouble

• Carry out diagnosis with particular emphasis on

connector(s) or wiring harness between the
powertrain control module 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.00-6

).

.

TROUBLESHOOTING HINTS

• The wiring harness or connectors may have

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

• Malfunction of powertrain control module

• Malfunction of combination meter

DIAGNOSIS

Required Special Tools:

• MB991958: Scan 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 AND VEHICLE SPEED SENSOR

TSB Revision

CHASSIS ELECTRICAL

54A-73

STEP 1. Using scan tool MB991958, diagnose the CAN bus
line.
Use scan tool MB991958 to diagnose the CAN bus lines.
(1) Connect scan 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-14

). On

completion, go to Step 6.

STEP 2. Using scan tool MB991958, read the MFI system
diagnostic trouble code.
Check if an MFI system DTC is set.
Q: Is the DTC set?

YES : Diagnose the MFI system by referring to GROUP

13A, MFI Diagnosis

− Diagnostic Trouble Code Chart

P.13A-34

or GROUP 13B, MFI Diagnosis

−

Diagnostic Trouble Code Chart

P.13B-33

.

NO : Go to Step 3.

STEP 3. Using scan 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 U1120: Failure information on powertrain control mod-
ule (related to engine) <vehicles with TCL>

• Multi-center display

DTC 020: Failure information on powertrain control module
(related to engine)

• A/C-ECU

DTC U1120: Failure information on powertrain control mod-
ule (related to engine)

Q: Is the DTC set?

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

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

COMBINATION METER ASSEMBLY AND VEHICLE SPEED SENSOR

TSB Revision

CHASSIS ELECTRICAL

54A-74

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 lines between the
powertrain control module and the combination meter
(Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points-How to
Cope with Intermittent Malfunction

P.00-6

).

NO : Replace powertrain control module 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 lines between the
powertrain control module and the combination meter
(Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points-How to
Cope with Intermittent Malfunction

P.00-6

).

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

STEP 6. 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.