2005 MITSUBISHI 380 ECU

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-411
CIRCUIT OPERATION
The ETACS-ECU operates the fog lamps according
to signal from the fog lamp switch.
.
TECHNICAL DESCRIPTION (COMMENT)
If the signal is not normal, the fog lamps do not work
normally. If the signal is not normal, the fog lamp
switch or the ETACS-ECU may be defective.
.
TROUBLESHOOTING HINTS
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
The fog lamp switch 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
DIAGNOSIS
Required Special Tool:
MB991223: Harness Set
STEP 1. Check fog lamp switch connector C-128 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is fog lamp switch connector C-128 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. Repair the fog lamp switch. If the fog lamp
switch operates normally, a correct signal is sent from
the fog lamp switch.
STEP 2. Check the fog lamp switch.
Remove the fog lamp switch. Refer to GROUP 54A, Fog lamp
P.54A-168. Then check continuity between the switch termi-
nals.
Q: Is the fog lamp switch in good condition?
YES : Go to Step 3.
NO : Repair the fog lamp switch. If the fog lamp switch
operates normally, a correct signal is sent from the
fog lamp switch.
SWITCH
POSITIONTESTER
CONNECTIONSPECIFIED
CONDITION
Released 1
2 Open circuit
Pressed 1
2 Less than 2 ohms

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-412
STEP 3. Check the ground circuit to the fog lamp switch.
Measure the resistance at fog lamp switch connector
C-128.
(1) Disconnect fog lamp switch connector C-128 and measure
the resistance available at the wiring harness side of the
connector.
(2) Measure the resistance value between terminal 2 and
ground.
The resistance should be 2 ohms or less.
Q: Is the measured resistance 2 ohms or less?
YES : Go to Step 5.
NO : Go to Step 4.
STEP 4. Check the wiring harness between fog lamp
switch connector C-128 (terminal 2) and ground.
Q: Is the wiring harness between fog lamp switch
connector C-128 (terminal 2) 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. If the fog
lamp switch operates normally, a correct signal is sent
from the fog lamp switch.
STEP 5. 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 6.
NO : Repair or replace the damaged component(s). Refer
to GROUP 00E, Harness Connector Inspection
P.00E-2. If the fog lamp switch operates normally, a
correct signal is sent from the fog lamp switch.

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-413
STEP 6. Check the wiring harness between fog lamp
switch connector C-128 (terminal 1) and ETACS-ECU
connector C-218 (terminal 48).
Q: Is the wiring harness between fog lamp switch
connector C-128 (terminal 1) and ETACS-ECU connector
C-218 (terminal 48) in good condition?
YES : Replace the ETACS-ECU. If the fog lamp switch
operates normally, a correct signal is sent from the
fog lamp switch.
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. If the fog
lamp switch operates normally, a correct signal is sent
from the fog lamp switch.
INSPECTION PROCEDURE M-4: ETACS-ECU does not receive any signal from the front door
switches.
.

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-414
CIRCUIT OPERATION
The ETACS-ECU operates the following functions or
systems according to signal from the front door
switches:
Light reminder tone alarm function switch (RH)>
Door ajar warning buzzer
Forgotten key reminder
Power window timer function
Sunroof timer function
Keyless entry system
Timed locking mechanism
Headlamp automatic shutdown function door switch (RH)>
Dome lamp
Interior lamp automatic-shutdown function
Ignition key hole illumination lamp switch (RH)>
Door-ajar indicator lamp
.
TECHNICAL DESCRIPTION (COMMENT)
If the signal is not normal, the functions or systems
described in "CIRCUIT OPERATION" do not work
normally. If the signal is not normal, the front door
switches or the ETACS-ECU may be defective.
.
TROUBLESHOOTING HINTS
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
The front door switches 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

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-415
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
STEP 1. Check the input signal (by using the pulse check
mode of the monitor).
Check the input signals from the front door switches.
To prevent damage to diagnostic tool MB991958, always
turn the ignition switch to the "LOCK" (OFF) position
before connecting or disconnecting diagnostic tool
MB991958.
(1) Connect the diagnostic tool MB991958.Refer to "How to
connect SWS monitor P.54B-13."
(2) Operate diagnostic tool MB991958 according to the
procedure below to display "Pulse check."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "Pulse Checking."
(3) Check that diagnostic tool MB991958 sounds.
Q: Does diagnostic tool MB991958 sound when each front
door is opened and closed?
When the front door (RH) is opened and closed,
diagnostic tool MB991958 does not sound. : Go to Step
2.
When the front door (LH) is opened and closed,
diagnostic tool MB991958 does not sound. : Go to Step
7.
When either front door is opened and closed, diagnostic
tool MB991958 sounds. : Replace the ETACS-ECU. If the
functions described in "CIRCUIT OPERATION" work
normally, the input signal from the front door switches
should be normal.
STEP 2. Check front door switch (RH) connector D-34 for
loose, corroded or damaged terminals, or terminals
pushed back in the connector.
Q: Is front door switch (RH) connector D-34 in good
condition?
YES : Go to Step 3.
NO : Repair or replace the damaged component(s). Refer
to GROUP 00E, Harness Connector Inspection
P.00E-2. If the functions described in "CIRCUIT
OPERATION" work normally, the input signal from the
front door switch (RH) should be normal.

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-416
STEP 3. Check the front door switch (LH).
Remove the front door switch (RH). Refer to GROUP 42, Door,
Door Assembly P.42-37. Then check continuity between the
switch terminals and the body ground.
Q: Is the front door switch (LH) in good condition?
YES : Go to Step 4.
NO : Replace the front door switch (RH). If the functions
described in "CIRCUIT OPERATION" work normally,
the input signal from the front door switch (RH) should
be normal.
STEP 4. Measure resistance at the lower metal part of the
front door switch (RH) in order to check the ground circuit
to the front door switch (RH).
NOTE: Check that the front door switch (RH) is grounded to the
vehicle body via its mounting screw.
Remove the cap, and measure the resistance value between
the lower metal part and ground.
The resistance should be 2 ohms or less.
Q: Is the measured resistance 2 ohms or less?
YES : Go to Step 5.
NO : Check the installation of the switch, and repair if
necessary. If the functions described in "CIRCUIT
OPERATION" work normally, the input signal from the
front door switch (RH) should be normal.
STEP 5. Check ETACS-ECU connector C-219 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is ETACS-ECU connector C-219 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. If the functions described in "CIRCUIT
OPERATION" work normally, the input signal from the
front door switch (LH) should be normal. SWITCH
POSITIONTESTER
CONNECTIONSPECIFIED
CONDITION
Released (ON) 1
body ground Less than 2 ohms
Pressed (OFF) 1
body ground Open circuit

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-417
STEP 6. Check the wiring harness between front door
switch (RH) connector D-34 (terminal 1) and ETACS-ECU
connector C-219 (terminal 10).
NOTE: Also check junction block connector C-204 for loose,
corroded, or damaged terminals, or terminals pushed back in
the connector. If junction block connector C-204 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 door switch (RH)
connector D-34 (terminal 1) and ETACS-ECU connector
C-219 (terminal 10) in good condition?
YES : Replace the ETACS-ECU. If the functions described
in "CIRCUIT OPERATION" work normally, the input
signal from the front door switch (RH) should be
normal.
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. If the
functions described in "CIRCUIT OPERATION" work
normally, the input signal from the front door switch
(RH) should be normal.

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-419
STEP 10. 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 11.
NO : Repair or replace the damaged component(s). Refer
to GROUP 00E, Harness Connector Inspection
P.00E-2. If the functions described in "CIRCUIT
OPERATION" work normally, the input signal from the
front door switch (LH) should be normal.
STEP 11. Check the wiring harness between front door
switch (LH) connector D-22 (terminal 1) and ETACS-ECU
connector C-218 (terminal 59).
Q: Is the wiring harness between front door switch (LH)
connector D-22 (terminal 1) and ETACS-ECU connector
C-218 (terminal 59) in good condition?
YES : Replace the ETACS-ECU. If the functions described
in "CIRCUIT OPERATION" work normally, the input
signal from the front door switch (LH) should be
normal.
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. If the
functions described in "CIRCUIT OPERATION" work
normally, the input signal from the front door switch
(LH) should be normal.