2005 MITSUBISHI 380 Relay box

SWS DIAGNOSIS
SIMPLIFIED WIRING SYSTEM (SWS)54B-10
SWS DIAGNOSIS
GENERAL DESCRIPTION
BEFORE CARRYING OUT TROUBLESHOOTINGM1549014700710
Before carrying out troubleshooting, check the fol-
lowing two items.
Make sure that the ETACS-ECU, the junction
block (J/B), the front-ECU and the engine com-
partment relay box are connected securely.
Make sure that fuses and fusible links related to
relevant systems are not blown.
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
DIAGNOSTIC FUNCTIONM1549028900245
ON-BOARD DIAGNOSTICS
If an error occurs in the ECU or the SWS or CAN
communication line which performs the SWS or CAN
communication, the DTC is memorized in
ETACS-ECU. The DTCs have 11 items. The DTCs
are checked to connect diagnostic tool MB991958
(MUT-III sub assembly). The memorised DTCs are
not erased even if the ignition switch is turned to the
LOCK (OFF) position. The DTCs are erased to oper-
ate diagnostic tool MB991958 (MUT-III sub assem-
bly).NOTE:
*1: For vehicles that do not have a sunroof,
the diagnosis code is always sent but it does not indi-
cate a problem.
NOTE:
*2: The diagnosis code for the current prob-
lem is not sent.
NOTE:
*3: For vehicles that do not have a multi cen-
ter display (middle grade type), the diagnosis code is
always sent but it does not indicate a problem.
HOW TO CONNECT THE DIAGNOSTIC TOOL
(MUT-III)
Required Special Tools:
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 DTC CODE TROUBLE CONTENT
001 or U1700 Malfunction of SWS communication line or ETACS-ECU
002 or U1701 Malfunction of column switch
003 or U1702 Malfunction of front-ECU
004
*1 or U1073Malfunction of sunroof-ECU
010
*2 or U1073Bus Off
011 or U1100 Engine ECU time-out
012 or U1101 A/T ECU time-out
013 or U1110 A/C-ECU time-out
014 or U1108 Combination meter time-out
015
*3 or U1111Multi center display unit time-out
021 or U1128 Failure information on combination meter

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-83
STEP 2. 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 3.
NO : Repair or replace the damaged component(s). Refer
to GROUP 00E, Harness Connector Inspection
P.00E-2. The system should communicate with the
front-ECU normally.
STEP 3. 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 5 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 5.
NO : Go to Step 4.

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-84
STEP 4. Check the wiring harness between front-ECU
connector A-11X (terminal 5) and the battery.
Q: Is the wiring harness between front-ECU connector
A-11X (terminal 5) 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 front-ECU 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 system should communicate with the
front-ECU normally.
STEP 6. Check the ground circuit to the front-ECU.
Measure the resistance 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) Measure the resistance value between terminal 21 and
ground.
The resistance should be 2 ohms or less.
Q: Is the measured resistance 2 ohms or less?
YES : Go to Step 8.
NO : Go to Step 7.

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-199
STEP 17. Check the battery power supply circuit to the
horn relay. Measure the voltage at horn relay connector
A-06X.
(1) Disconnect horn relay connector A-06X 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 19.
NO : Go to Step 18.
STEP 18. Check the wiring harness between horn relay
connector A-06X (terminals 1 and 2) and the battery.
Q: Is the wiring harness between horn relay connector
A-06X (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 horn sounds normally.
STEP 19. Check ETACS-ECU connector C-217 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is ETACS-ECU connector C-217 in good condition?
YES : Go to Step 20.
NO : Repair or replace the damaged component(s). Refer
to GROUP 00E, Harness Connector Inspection
P.00E-2. Verify that the horn sounds normally.

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-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-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-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.