ECU MITSUBISHI 380 2005 Workshop Manual

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-232
STEP 8. Check the ignition switch (ACC) circuit to the
front-ECU. Measure the voltage at front-ECU connector
A-12X.
(1) Disconnect front-ECU connector A-12X and measure the
resistance available at the relay box side of the connector.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal 28 and ground.
The voltage should measure approximately 12 volts
(battery positive voltage).
Q: Is the measured voltage approximately 12 volts (battery
positive voltage)?
YES : Replace the front-ECU. Verify that the windshield
wiper works normally.
NO : Go to Step 9.
STEP 9. Check the wiring harness between front-ECU
connector A-12X (terminal 28) and the ignition switch
(ACC).

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-233
NOTE: Also check intermediate connector C-29 for loose, cor-
roded, or damaged terminals, or terminals pushed back in the
connector. If intermediate connector C-29 is damaged, repair or
replace the damaged component(s) as described in GROUP
00E, Harness Connector Inspection P.00E-2.
Q: Is the wiring harness between front-ECU connector
A-12X (terminal 28) and the ignition switch (ACC) in
good condition?
YES : No action is necessary and testing is complete.
NO : The wiring harness may be damaged or the
connector(s) may have loose, corroded or damaged
terminals, or terminals pushed back in the connector.
Repair the wiring harness as necessary. Verify that
the windshield wiper works normally.

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-234
INSPECTION PROCEDURE G-2: Windshield Wiper and Washer: The windshield wipers do not work
when the windshield wiper switch is at "INT" or "MIST" position or the windshield washer switch is at
"ON" position. However, the wipers work at low speed when the windshield wiper switch is at "LO" or
"HI."
NOTE: This troubleshooting procedure requires use
of Diagnostic Tool MB991958 and SWS monitor kit
MB991813. For details on how to use the SWS mon-
itor, refer to "How to connect SWS monitor
P.54B-13."
.
TECHNICAL DESCRIPTION (COMMENT)
This system may be at fail-safe mode as the SWS
communication line is defective.
If the system cannot receive any signal from the col-
umn switch (windshield wiper and washer switch)
due to a open circuit in the SWS communication line
or other reasons, the system will enter the fail-safe
mode when the ignition switch is at the "ACC" posi-
tion.
.
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
The column switch may be defective
The front-ECU may be defective
DIAGNOSIS
Required Special Tools:
MB991223: Harness Set
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
MB991813: SWS Monitor Kit
MB991806: SWS Monitor Cartridge
MB991812: SWS Monitor Harness (For Column-ECU)
MB991822: Test Probe Harness

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-235
Use Diagnostic Tool MB991958 to select "ECU COMM
Check" on the SWS monitor display.
Check the following ECUs:
Column-ECU
Front-ECU
To prevent damage to Diagnostic Tool MB991958, always
turn the ignition switch to the "LOCK" (OFF) position
before connecting or disconnecting Diagnostic Tool
MB991958. Connect special tool MB991910 before con-
necting special tool MB991812. Be sure to connect special
tool MB991806 after turning on special tool MB991824.
(1) Connect the special tool. Refer to "How to connect SWS
monitor P.54B-13."
(2) Turn the ignition switch to the "ON" position.
(3) Operate Diagnostic Tool MB991958 according to the
procedure below to display "ECU COMM CHECK."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "ECU COMM Check."
(4) Diagnostic Tool MB991958 should show "OK" on the "ECU
COMM Check" menus for both the "COLUMN ECU" and
the "FRONT ECU" menus.
Q: Is "OK" displayed for the "COLUMN ECU" and "FRONT
ECU" menu?
"OK" is displayed for all the items : Replace the
front-ECU. Verify that the windshield wiper works
normally.
"NG" is displayed for the "COLUMN ECU" menu : Refer
to Inspection Procedure A-2 "Communication with the
column switch (column-ECU) is not possible
P.54B-68."
"NG" is displayed for the "FRONT ECU" menu : Refer to
Inspection procedure A-4 "Communication with the
front-ECU is not possible P.54B-80."

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-236
INSPECTION PROCEDURE G-3: Windshield Wiper and Washer: All of the windshield wiper switch
positions are defective.
NOTE: This troubleshooting procedure requires use
of Diagnostic Tool MB991958 and SWS monitor kit
MB991813. For details on how to use the SWS mon-
itor, refer to "How to connect SWS monitor
P.54B-13."
.
TECHNICAL DESCRIPTION (COMMENT)
If either of the windshield wiper switch positions is
defective, the windshield wiper motor, column switch
(windshield wiper and washer switch) or the
front-ECU may be defective.
.
TROUBLESHOOTING HINTS
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
Trouble in input signal system
The wiring harness or connectors may have
loose, corroded, or damaged terminals, or termi-
nals pushed back in the connector
The wiper motor may be defective
The front-ECU may be defective
DIAGNOSIS
Required Special Tools:
MB991223: Harness Set
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
MB991813: SWS Monitor Kit
MB991806: SWS Monitor Cartridge
MB991812: SWS Monitor Harness (For Column-ECU)
MB991822: Test Probe Harness

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-237
STEP 1. Check the input signal by using "DATA LIST"
menu of the SWS monitor.
Turn the ignition switch to the ACC position before checking
input signals from the windshield wiper switch.
To prevent damage to Diagnostic Tool MB991958, always
turn the ignition switch to the "LOCK" (OFF) position
before connecting or disconnecting Diagnostic Tool
MB991958. Connect special tool MB991910 before con-
necting special tool MB991812. Be sure to connect special
tool MB991806 after turning on special tool MB991824.
(1) Connect the special tool. Refer to "How to connect SWS
monitor P.54B-13."
(2) Operate Diagnostic Tool MB991958 according to the
procedure below to display "COLUMN ECU."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "Data List."
f. Select "COLUMN ECU."
(3) Check that normal conditions are displayed for the items
described in the table below.
Q: Are normal conditions displayed for "INT WIPER SW",
"LO WIPER SW", "HI WIPER SW" and "MIST WIPER
SW"?
YES : Go to Step 2.
NO : Refer to Inspection Procedure M-6 "ETACS-ECU
does not receive any signal from the windshield mist
wiper switch P.54B-423." ITEM NO. ITEM NAME NORMAL
CONDITION
ITEM 05 INT WIPER SW ON
ITEM 06 LO WIPER SW ON
ITEM 07 HI WIPER SW ON
ITEM 08 MIST WIPER SW ON

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-239
STEP 4. Check front-ECU connector A-12X for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is front-ECU connector A-12X in good condition?
YES : Go to Step 5.
NO : Repair or replace the damaged component(s). Refer
to GROUP 00E, Harness Connector Inspection
P.00E-2. Verify that the windshield wiper operates
normally when the windshield wiper switch is moved
to each position.
STEP 5. Check the wiring harness between windshield
wiper motor connector A-03 (terminals 5 and 4) and
front-ECU connector A-12X (terminals 25 and 24).
Q: Is the wiring harness between windshield wiper motor
connector A-03 (terminals 5 and 4) and front-ECU
connector A-12X (terminals 25 and 24) in good
condition?
YES : No action is necessary and testing is complete.
NO : The wiring harness may be damaged or the
connector(s) may have loose, corroded or damaged
terminals, or terminals pushed back in the connector.
Repair the wiring harness as necessary. Verify that
the windshield wiper operates normally when the
windshield wiper switch is moved to each position.

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-241
TECHNICAL DESCRIPTION (COMMENT)
If the windshield wipers do not stop at predetermined
park position, the windshield wiper motor or the
front-ECU may be defective.
.
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
The windshield wiper motor may be defective
The front-ECU may be defective
DIAGNOSIS
Required Special Tool:
MB991223: Harness Set
STEP1. Check windshield wiper motor connector A-03 for
loose, corroded or damaged terminals, or terminals
pushed back in the connector.
Q: Is windshield wiper motor connector A-03 in good
condition?
YES : Go to Step 2.
NO : Repair or replace the damaged component(s). Refer
to GROUP 00E, Harness Connector Inspection
P.00E-2. Verify that the windshield wiper works
normally.

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-244
NOTE: Also check intermediate connector C-29 for loose, cor-
roded, or damaged terminals, or terminals pushed back in the
connector. If intermediate connector C-29 is damaged, repair or
replace the damaged component(s) as described in GROUP
00E, Harness Connector Inspection P.00E-2.
Q: Is the wiring harness between windshield wiper motor
connector A-03 (terminal 3) and the ignition switch
(ACC) in good condition?
YES : No action is necessary and testing is complete.
NO : The wiring harness may be damaged or the
connector(s) may have loose, corroded or damaged
terminals, or terminals pushed back in the connector.
Repair the wiring harness as necessary. Verify that
the windshield wiper works normally.
STEP 5. Check front-ECU connector A-12X for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is front-ECU connector A-12X in good condition?
YES : Go to Step 6.
NO : Repair or replace the damaged component(s). Refer
to GROUP 00E, Harness Connector Inspection
P.00E-2. The windshield wiper should stop at the
predetermined park position.

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-245
STEP 6. Check the wiring harness between windshield
wiper motor connector A-03 (terminal 2) and front-ECU
connector A-12X (terminal 29).
Q: Is the wiring harness between windshield wiper motor
connector A-03 (terminal 2) and front-ECU connector
A-12X (terminal 29) in good condition?
YES : Replace the front-ECU. The windshield wiper should
stop at the predetermined park position.
NO : The wiring harness may be damaged or the
connector(s) may have loose, corroded or damaged
terminals, or terminals pushed back in the connector.
Repair the wiring harness as necessary. Verify that
the windshield wiper works normally