relay MITSUBISHI 380 2005 Service Manual

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-263
STEP 3. Check front-ECU connector A-11X for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is front-ECU connector A-11X 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 taillamps illuminate normally.
STEP 4. Check the battery power supply circuit to the
front-ECU. Measure the voltage at front-ECU connector
A-11X.
(1) Disconnect front-ECU connector A-11X and measure the
voltage available at the relay box side of the connector.
(2) Measure the voltage between terminal 7 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 taillamps
illuminate normally.
NO : Go to Step 5.

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-264
STEP 5. Check the wiring harness between front-ECU
connector A-11X (terminal 7) and the battery.
Q: Is the wiring harness between front-ECU connector
A-11X (terminal 7) 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. Verify that
the taillamps illuminate normally.
INSPECTION PROCEDURE H-2: Headlamp and Taillamp: The headlamps (low-beam) do not illuminate
normally.
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
When the lighting switch is set to "HEAD" posi-
tion, the "HEAD" signal is sent through the col-
umn-ECU (incorporated in the column switch) to
the front-ECU. If the front-ECU receives the
"HEAD" signal through the column-ECU, the
front-ECU turns on the headlamp relay (incorpo-
rated in the front-ECU), thus causing the
headlamps to illuminate. The headlamps always
illuminate at low-beam by the headlamp dimmer
switch automatic resetting function.
If the SWS communication line is defective, the
front-ECU operates the headlamps by using the
other communication lines (headlamp backup cir-
cuit) instead of that line.
.
TECHNICAL DESCRIPTION (COMMENT)
If the headlamps (low-beam) do not illuminate nor-
mally, the column 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 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

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-267
STEP 3. Check front-ECU connector A-11X for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is front-ECU connector A-11X 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 headlamps (low-beam)
illuminate normally.
STEP 4. Check the battery power supply circuit to the
front-ECU. Measure the voltage at front-ECU connector
A-11X.
(1) Disconnect front-ECU connector A-11X and measure the
voltage available at the relay box side of the connector.
(2) Measure the voltage between terminal numbers 8 and
ground, and also between terminal 9 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 headlamps
(low-beam) illuminate normally.
NO : Go to Step 5.

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-340
INSPECTION PROCEDURE J-1: Fog Light: Fog lamps do not illuminate when the fog lamp switch is
turned on.
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 ETACS-ECU sends a fog lamp illumination
request signal ("LAMP ON" signal) to the
front-ECU when the fog lamp switch is turned on
while the headlamps are illuminating at low
beam.
Then the front-ECU switches on its relay to illumi-
nate the fog lamps.
.
TECHNICAL DESCRIPTION (COMMENT)
If the headlamps illuminate at low beam, the fog
lamp relay, the fog lamp switch, the front-ECU or the
ETACS-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 fog lamp relay may be defective
The front-ECU 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: Test Probe Harness
STEP 1. Check the headlamp (low-beam) operation.
Q: Do the headlamps illuminate at low beam normally?
YES : Go to Step 2.
NO : Refer to Inspection Procedure H-2 "The headlamps
(low-beam) do not illuminate normally P.54B-264."

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-342
STEP 3. Check fog lamp relay connector A-05X for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is fog lamp relay connector A-05X 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 fog lamps illuminate normally.
STEP 4. Check the fog lamp relay.
Q: Is the fog lamp relay in good condition?
YES : Go to Step 5.
NO : Replace the fog lamp relay. Verify that the fog lamps
illuminate normally.
BATTERY VOLTAGE TESTER
CONNECTIONSPECIFIED
CONDITION
Not applied 1
4 Open circuit
Connect terminal 2
to the positive
battery terminal
Connect terminal 3
to the negative
battery terminal1
4 Less than 2 ohms

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-343
STEP 5. Check the battery power supply circuit to the fog
lamp relay. Measure the voltage at fog lamp relay
connector A-05X.
The top and bottom of the fog lamp relay are difficult to
identify. Prior to inspection, confirm the triangle mark on
the relay box.
(1) Disconnect fog lamp relay connector A-05X and measure
the voltage available at the relay box side of the connector.
(2) Measure the voltage between terminal 1 and ground, and
also between terminal 2 and ground.
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 7.
NO : Go to Step 6.
STEP 6. Check the wiring harness between fog lamp relay
connector A-05X (terminals 1 and 2) and the battery.
Q: Is the wiring harness between fog lamp relay connector
A-05X (terminals 1 and 2) 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. Verify that
the fog lamps illuminate normally.

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-344
STEP 7. Check front-ECU connector A-11X for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is front-ECU connector A-11X 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. Verify that the fog lamps illuminate normally.
STEP 8. Check the wiring harness between fog lamp relay
connector A-05X (terminal 3) and front-ECU connector
A-11X (terminal 11).
Q: Is the wiring harness between fog lamp relay connector
A-05X (terminal 3) and front-ECU connector A-11X
(terminal 11) 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. Verify that
the fog lamps illuminate normally.
STEP 9. Replace the ECU.
(1) Replace the front-ECU.
(2) The fog lamps should illuminate normally.
Q: Do the fog lamps illuminate normally?
YES : No action is necessary and testing is complete.
NO : Replace the ETACS-ECU. Verify that the fog lamps
illuminate normally.

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-345
INSPECTION PROCEDURE J-2: Fog Light: Fog lamps do not go out when the headlamps (low-beam)
are turned off while the fog lamps are on.
.
TECHNICAL DESCRIPTION (COMMENT)
If the trouble above occurs, the front-ECU may be
defective.
.
TROUBLESHOOTING HINT
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
The front-ECU may be defective
DIAGNOSIS
Replace the front-ECU.
The fog lamps should go out when the headlamps (low-beam)
are turned off while the fog lamps are on.
INSPECTION PROCEDURE J-3: Fog Light: One of the fog lamps does not illuminate.
.
TECHNICAL DESCRIPTION (COMMENT)
If one of the fog lamps does not illuminate, the fog
lamp relay or the fog lamp bulb may be defective. If
the fog lamp indicator lamp does not illuminate, the
combination meter 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 fog lamp bulb may be defective
.
DIAGNOSIS
Required Special Tool:
MB991223: Harness Set

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-347
STEP 4. Check the ground circuit to the fog lamp (LH).
Measure the resistance at fog lamp (LH) connector A-22.
(1) Disconnect fog lamp (LH) connector A-22 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 6.
NO : Go to Step 5.
STEP 5. Check the wiring harness between fog lamp (LH)
connector A-22 (terminal 2) and ground.
Q: Is the wiring harness between fog lamp (LH) connector
A-22 (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. Verify that
the fog lamps illuminate normally.
STEP 6. Check fog lamp relay connector A-05X for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is fog lamp relay connector A-05X 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. Check that the fog lamps illuminate
normally.

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-348
STEP 7. Check the wiring harness between fog lamp relay
connector A-05X (terminal 4) and fog lamp (LH) connector
A-22 (terminal 1).
Q: Is the wiring harness between fog lamp relay connector
A-05X (terminal 4) and fog lamp (LH) connector A-22
(terminal 1) 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 fog lamps illuminate normally.
STEP 8. Check fog lamp (RH) connector A-28 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is fog lamp (RH) connector A-28 in good condition?
YES : Go to Step 9.
NO : Repair or replace the damaged component(s). Refer
to GROUP 00E, Harness Connector Inspection
P.00E-2. Check that the fog lamps illuminate
normally.
STEP 9. Check the fog lamp bulb (RH).
(1) Remove the fog lamp bulb (RH).
(2) Verify that the fog lamp bulb (RH) is not damaged or burned
out.
Q: Is the fog lamp bulb (RH) in good condition?
YES : Go to Step 10.
NO : Replace the fog lamp bulb (RH). Verify that the fog
lamps illuminate normally.