ECU MITSUBISHI 380 2005 Repair Manual

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-63
SYMPTOM PROCEDURES
INSPECTION PROCEDURE A-1: Communication with the SWS Monitor Kit is not Possible.
.
TECHNICAL DESCRIPTION (COMMENT)
The SWS monitor kit may be connected improperly.
.
TROUBLESHOOTING HINTS
The SWS monitor body (I/F cartridge) may be
defective
The SWS monitor harness may be defective
The wiring harness or connectors may have
loose, corroded, or damaged terminals, or termi-
nals pushed back in the connector
The ETACS-ECU may be defective
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
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: Probe Harness

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-64
STEP 1. Verify SWS monitor kit MB991813 for proper
connection.
Q: Is SWS monitor kit MB991813 connected with the
column switch properly?
YES : Go to Step 2.
NO : Connect SWS monitor kit MB991813 to the column
switch securely.
STEP 2. Verify the power supply circuit to the ETACS-ECU.
Q: Does the system communicate with diagnostic tool
MB991958 when the ignition switch is turned to the
"ON" position?
YES : Refer to Inspection Procedure A-3 "Communication
with the ETACS-ECU is not possible P.54B-74."
NO : Go to Step 3.
STEP 3. Check ETACS-ECU connectors C-218 and C-219
for loose, corroded or damaged terminals, or terminals
pushed back in the connector.
Q: Are ETACS-ECU connectors C-218 and C-219 in good
condition?
YES : Go to Step 4.
NO : Repair or replace the damaged component(s). Refer
to GROUP 00E, Harness Connector Inspection
P.00E-2. Verify that the system should communicate
with the SWS monitor normally.

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-65
STEP 4. Check the ground circuit to the ETACS-ECU.
Measure the resistance at ETACS-ECU connectors C-218
and C-219.
(1) Disconnect ETACS-ECU connectors C-218 and C-219, and
measure the resistance available at the junction block side
of the connector.
(2) Measure the resistance value between ETACS-ECU
connector C-218 terminal 50 and ground.
The resistance should be 2 ohms or less.
Measure the resistance value between ETACS-ECU
connector C-219 terminal 3 and ground.
The resistance should be 2 ohms or less.
Q: Is the measured resistance 2 ohms or less?
YES : Go to Step 6.
NO : Go to Step 5.

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-66
STEP 5. Check the wiring harness between ETACS-ECU
connector C-218 (terminal 50) or ETACS-ECU connector
C-219 (terminal 3) and ground.
NOTE: Also check junction block connector C-211 for loose,
corroded, or damaged terminals, or terminals pushed back in
the connector. If junction block connector C-211 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 ETACS-ECU connector
C-218 (terminal 50) or ETACS-ECU connector C-219
(terminal 3) and ground 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 system should communicate with the SWS
monitor kit normally.

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-67
STEP 6. Check data link connector C-125 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is data link connector C-125 in good condition?
YES : Go to Step 7.
NO : Repair or replace the damaged component(s). Refer
to GROUP 00E, Harness Connector Inspection
P.00E-2. Verify that the system should communicate
with the SWS monitor kit normally.
STEP 7. Check the wiring harness between ETACS-ECU
connector C-218 (terminals 45, 53 and 61) and data link
connector C-125 (terminals 9, 3 and 1).
Q: Is the wiring harness between ETACS-ECU connector
C-218 (terminals 45, 53 and 61) and data link connector
C-125 (terminals 9, 3 and 1) in good condition?
YES : Replace the ETACS-ECU. The system should
communicate with the SWS monitor kit normally.
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 system should communicate with the SWS
monitor kit normally.

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-68
INSPECTION PROCEDURE A-2: Communication with the Column Switch (column-ECU) is not
Possible.
NOTE: This troubleshooting procedure requires the
use of diagnostic tool MB991958 and SWS monitor
kit MB991813. For details on how to use the SWS
monitor, refer to "How to connect SWS monitor
P.54B-13."
.
CIRCUIT OPERATION
The power supply to the column switch is pro-
vided by the battery and the ignition switch (IG1).
If the power supply system from the battery is
defective, the system operates by the power sup-
ply from the ignition switch (IG1).
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
.
TECHNICAL DESCRIPTION (COMMENT)
The power supply circuit to the column switch (col-
umn-ECU) may be defective. If the battery power
supply circuit (terminal 1 of the column switch) to the
ECU is damaged, also check the power supply circuit
from the ignition switch (IG1) (terminal 9 of the col-
umn switch), and repair if necessary.
.
TROUBLESHOOTING HINTS
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 ETACS-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: Probe Harness

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-69
STEP 1. Use diagnostic tool MB991958 to select "ECU
COMM Check" on the SWS monitor display.
Check the following ECUs:
ETACS-ECU
Column-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 "ETACS ECU"
and the "COLUMN ECU" menus.
Q: Is "OK" displayed for both the "ETACS ECU" and
"COLUMN ECU" menus?
"OK" is displayed for all the items : Go to Step 2.
"NG" is displayed for the "COLUMN ECU" menu : Go to
St e p 6 .
"NG" is displayed for the "ETACS ECU" menu : Refer to
Inspection Procedure A-3 "Communication with the
ETACS-ECU is not possible P.54B-74."
"NG" is displayed for all the items : Refer to Inspection
Procedure A-3 "Communication with the ETACS-ECU
is not possible P.54B-74."

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-70
STEP 2. Check column switch connector C-309 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is column switch connector C-309 in good condition?
YES : Go to Step 3.
NO : Repair or replace the damaged component(s). The
system should communicate with the column switch
(column-ECU) normally.
STEP 3. Check the power supply circuit to the column
switch. Measure the voltage at column switch connector
C-309.
(1) Disconnect column switch connector C-309 and measure
the voltage available at the wiring harness side of the
connector.
(2) Measure the voltage between terminal 1 and ground by
backprobing.
The voltage should measure approximately 12 volts
(battery positive voltage).
Q: Is the measured voltage approximately 12 volts (battery
positive voltage)?
YES : Go to Step 5.
NO : Go to Step 4.
STEP 4. Check the wiring harness between column switch
connector C-309 (terminal 1) and the battery.

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-71
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 connector as described in GROUP 00E, Harness
Connector Inspection P.00E-2.
Q: Is the wiring harness between column switch connector
C-309 (terminal 1) and the battery 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. The system
should communicate with the column switch
(column-ECU) normally.
STEP 5. Check the ground circuit to the column switch.
Measure the resistance at column switch connector C-309.
(1) Disconnect column switch connector C-309 and measure
the resistance available at the wiring harness side of the
connector.
(2) Measure the resistance value between terminal 4 and
ground.
The resistance should be 2 ohms or less.
Q: Is the measured resistance 2 ohms or less?
YES : Go to Step 7.
NO : Go to Step 6.

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-72
STEP 6. Check the wiring harness between column switch
connector C-309 (terminal 4) and ground.
Q: Is the wiring harness between column switch connector
C-309 (terminal 4) and ground 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. The system
should communicate with the column switch
(column-ECU) normally.
STEP 7. Check ETACS-ECU connector C-218 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is ETACS-ECU connector C-218 in good condition?
YES : Go to Step 8.
NO : Repair or replace the damaged component(s). Refer
to GROUP 00E, Harness Connector Inspection
P.00E-2. The system should communicate with the
column switch (column-ECU) normally.
STEP 8. Check the wiring harness between column switch
connector C-309 (terminal 3) and ETACS-ECU connector
C-218 (terminal 53).
Q: Is the wiring harness between column switch connector
C-309 (terminal 3) and ETACS-ECU connector C-218
(terminal 53) in good condition?
YES : Go to Step 9.
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. The system
should communicate with the column switch
(column-ECU) normally.