Mitsubishi Galant 9G. Manual — part 4

SWS DIAGNOSIS

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-12

HOW TO DIAGNOSE THE CAN BUS LINES

Required Special Tools:

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

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

• MB991827: MUT-III USB Cable

• MB991910: MUT-III Main Harness A

CAUTION

To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Select "CAN bus diagnosis" from the start-up screen.
4. When the vehicle information is displayed, confirm that it

matches the vehicle being diagnosed.

• If they match, go to step 8.

• If not, go to step 5.

5. Select the "view vehicle information" button.
6. Enter the vehicle information and select the "OK" button.
7. When the vehicle information is displayed, confirm again

that it matches the vehicle being diagnosed.

• If they match, go to step 8.

• If not, go to step 5.

8. Select the "OK" button.
9. When the optional equipment screen is displayed, choose

the one which the vehicle is fitted with, and then select the
"OK" button.

SWS DIAGNOSTIC TROUBLESHOOTING STRATEGY

M1549000500906

1. Gather information about the problem from the

customer.

2. Verify that the condition described by the

customer exists.
NOTE: If an error occurs in the SWS communica-
tion line, the ECU isolated from the communica-
tion line performs a fail-safe or backup operation,
so the problem may not match the one shown in
the Trouble Symptom Chart. However, the cause
of the failure can be tracked down by performing
the following troubleshooting with the SWS moni-
tor.

3. Version number and destination check

Check whether the SWS version number (1) and
destination (North America) meet the vehicle
specifications. If they are different, replace the
ETACS-ECU with a correct one.

4. Use scan tool MB991958 (MUT-III Sub Assembly)

to select "ECU COMM Check" on the SWS
monitor display.

Check whether the communication status of the
input- or output-signal-side ECU associated with
the defective function is normal.

• If "OK" is displayed for all related ECUs, they

communicate with each other normally and the
input or output signal circuit system may be
defective. Therefore, check SWS monitor service
data.

• If "NG" is displayed for any of the related ECUs,

something may be wrong with the ECU for which
"NG" appears, its power supply or grounding sys-
tem, or a wiring harness or connector between
the SWS monitor and the ECU. Check the wiring
harness and connectors associated with the ECU
and examine the ECU itself.

5. Service data on the SWS monitor

Select the defective function from the
function-specific diagnostic menu, and check the
service data that appears for each function item.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SWS DIAGNOSIS

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-13

When the SWS communication line is monitored,
you can determine whether the problem lies in the
input or output signal circuit system by checking
whether communication data is correct:

• If the switch condition does not meet the service

data display, the input signal is defective.

• If the switch condition meets the service data dis-

play, the output signal system is defective.

NOTE: In addition to the function-specific diag-
nostic menu, a service data menu is available for
SWS monitor service data to check all items for
each ECU.

6. Check the input signal circuit system

Check the relevant switch, sensor, input
signal-side ECU and their wiring harness and
connector.

7. Check the output signal circuit system

Check an output signal-side ECU, electrical load
components and their wiring harness and
connector.

HOW TO CONNECT SWS MONITOR

M1549014800706

Required Special Tools:

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

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

• MB991827: MUT-III USB Cable

• MB991910: MUT-III Main Harness A

• MB991813: SWS Monitor Kit

• MB991806: SWS Monitor Cartridge

• MB991812: SWS Monitor Harness (For Column-ECU)

• MB991822: Probe Harness

CAUTION

To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958. Connect
the main harness A MB991910 before connecting the SWS
monitor harness (for column-ECU) MB991812. Be sure to
connect SWS monitor cartridge MB991806 after turning on
the V.C.I. MB991924.
1. Ensure that the ignition switch is at the "LOCK" (OFF)

position.

2. Start up the personal computer.
3. Connect special tool MB991827 to special tool MB991824

and the personal computer.

4. Connect special tool MB991910 to special tool MB991824.
5. Connect special tool MB991910 to the data link connector.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SWS DIAGNOSIS

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-14

6. Remove the steering column cover.
7. Remove the steering column switch connector.
8. Connect special tool MB991812 to the column switch

connector.

9. Connect special tool MB991812 to special tool MB991806.
10.Connect special tool MB991806 to special tool MB991824.
11.Turn the power switch of special tool MB991824 to the "ON"

position.
NOTE: When special tool MB991824 is energized, special
tool MB991824 indicator light will be illuminated in a green
color.

12.Start the MUT-III system on the personal computer.

AC302210

COLUMN SWITCH
CONNECTOR

COLUMN SWITCH
CONNECTOR AT
HARNESS SIDE

MB991812

AB

AC208681

MB991806

AB

MB991812

MB991824

MB991910

MB991827

SWS DIAGNOSIS

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SIMPLIFIED WIRING SYSTEM (SWS)

54B-15

HOW TO USE SWS MONITOR

M1549020400332

To carry out troubleshooting, operate scan tool
MB991958 (MUT-III Sub Assembly) as follows.

Interactive

Diagnosis

TIR

Technical Infomation

Retrieval

Tutorial

Maintenance

Power Down

Menu

Function Select Menu

CAN bus diagnosis

MUT-3 Function Select Menu

Special Function

System Select

POWERTRAIN

UNDER CAR

System Check

SRS-AIR BAG

AUTO A/C

ETACS

SWS

BODY

Select system

Drive Recorder

Drive Recorder

Simulated Vehicle Speed
Output

Actuator T

Actuator Test

est

SWS

Check Chart For Problem
Symptom

Select function

Self-diagnosis

Pulse Checking

Special Function

Voltmeter

Data List

Data List

SWS MONITOR

SWS

BODY

Pulse check

Pulse check

SWS

BODY

Simulated vehicle speed output

Pulse check

L

H

L

-10

0

SWS Ver. Destination

Item

Value

Ver. 0

Ver. 1

Ver. 2

Ver. 3

PASSENGER CAR

MMMA PRODUCTS (GALANT, ECLIPSE)

MINI CARS

SWS monitor

SWS monitor

SWS

BODY

Check SWS version and destination and press "OK" button.

SWS Ver.

SWS Destination

1

NAS

SWS Ver. List

Item

Information

AC207214

Maintenance

Meter

Diplay

Resistor

Start-up the MUT-III system.

Select "Interactive Diagnosis"

Select "System Select".

Select "SWS" from the "BODY" tab.

For the SWS monitor, select
"SWS MONITOR".

For the pulse check, select
"Pulse Checking".

Confirm the SWS version and
destination.

AB

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