Page 335 of 1500

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-335
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 rear combination lamp
(RH) connector F-03 (terminal 5) and ETACS-ECU
connector C-219 (terminal 9) in good condition?
YES : Replace the rear combination lamp socket assembly
(RH). Verify that the turn-signal lamps illuminate
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 turn-signal lamps illuminate normally.
INSPECTION PROCEDURE I-4: The turn-signal lamp indicator does 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
At the same time that the turn-signal lamps are illu-
minated, the ETACS-ECU sends a signal to illumi-
nate the turn-signal lamp indicator via the CAN bus
line.
.
TECHNICAL DESCRIPTION (COMMENT)
If the turn-signal indicator does not illuminate nor-
mally, connector(s), wiring harness in the CAN bus
lines, the ETACS-ECU or 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 combination meter may be defective
The ETACS-ECU may be defective
.
Page 340 of 1500

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."
Page 350 of 1500
SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-350
STEP 13. Check the wiring harness between fog lamp relay
connector A-05X (terminal 4) and fog lamp (RH) connector
A-28 (terminal 1).
Q: Is the wiring harness between fog lamp relay connector
A-05X (terminal 4) and fog lamp (RH) connector A-28
(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.
INSPECTION PROCEDURE J-4: The fog lamp indicator does 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."
.
Page 359 of 1500

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-359
INSPECTION PROCEDURE K-1: Interior Light: The dome lamp do not illuminate and go out 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
The ETACS-ECU operates the dome lamp according
to the following signals:
Ignition switch (IG1): ON or OFF
Key reminder switch: ON or OFF
Door switches: ON or OFF
Driver’s door lock actuator switch: ON or OFF
Interior lamp loaded signal: ON
.
TECHNICAL DESCRIPTION (COMMENT)
If the dome lamp does not illuminate normally, a
burned-out dome lamp bulb, the input circuits from
the switches described in "CIRCUIT OPERATION",
the power supply line to the switches 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 ETACS-ECU may be defective
Page 368 of 1500

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-368
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 which of the front dome lamp, rear dome
lamp or trunk lamp do not illuminate normally.
Q: Which of the front dome lamp, rear dome lamp or trunk
lamp fail to illuminate normally?
Front dome lamp and rear dome lamp : Go to Step 2.
Front dome lamp : Go to Step 4.
Rear dome lamp : Go to Step 9.
Tru n k l am p : Go to Step 14.
STEP 2. Check map lamp assembly connector D-02
, overhead console assembly connector
D-03 and ETACS-ECU connector C-219 for
loose, corroded or damaged terminals, or terminals
pushed back in the connector.
Q: Is map lamp assembly connector D-02
sunroof>, overhead console assembly connector D-03
and ETACS-ECU connector C-219 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. Check that the front dome lamp and rear
dome lamp illuminates normally.
Page 373 of 1500

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-373
STEP 13. Check the wiring harness between rear dome
lamp connector D-07 (terminals 1 and 2) and ETACS-ECU
connector C-219 (terminals 6 and 5).
Q: Is the wiring harness between rear dome lamp
connector D-07 (terminals 1 and 2) and ETACS-ECU
connector C-219 (terminals 6 and 5) in good condition?
YES : Replace the rear dome lamp. Check that the rear
dome lamp illuminates 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. Check that
the rear dome lamp illuminates normally.
STEP 14. Check the input signal (by using the pulse check
mode of the monitor).
Check the input signals from the trunk lid latch assembly.
Check whether diagnostic tool MB991958 sounds or not
when the trunk is opened.
(1) Operate diagnostic tool MB991958 according to the
procedure below to display "Pulse checking."
a. Select "Interactive Diagnosis."
b. Select "System Select."
c. Select "SWS."
d. Select "Pulse Checking."
Q: Does diagnostic tool MB991958 sound when the trunk is
opened and closed?
YES : Go to Step 15.
NO : Refer to Inspection Procedure N-7 "ETACS-ECU
does not receive any signal from the trunk lid latch
assembly P.54B-469."
Page 376 of 1500

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-376
NOTE: Also check intermediate connector C-28 and junction
block connector C-204 for loose, corroded, or damaged termi-
nals, or terminals pushed back in the connector. If intermediate
connector C-28 or 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 trunk lamp connector
D-10 (terminals 1 and 2) and ETACS-ECU connector
C-219 (terminal 6) or C-218 (terminal 46) in good
condition?
YES : Replace the trunk lamp. Check that the trunk lamp
illuminates 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. Check that
the trunk lamp illuminates normally.
INSPECTION PROCEDURE K-3: Interior lamp: Dome lamp dimming function does not work 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."
.
Page 377 of 1500

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-377
CIRCUIT OPERATION
The ETACS-ECU operates the dome lamp dimming
function according to the input signals from the fol-
lowing switches:
Ignition switch (IG1): OFF
Key reminder switch: ON
Door switches: OFF
Driver's door lock actuator switch: LOCK or
UNLOCK
.
TECHNICAL DESCRIPTION (COMMENT)
If the dome lamps do not dim normally, the input cir-
cuits from the switches described in "CIRCUIT
OPERATION" 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 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 dome lamp.
If a door is opened while the dome lamp switch is at
"door-linked" position, the dome lamp should illuminate.
Q: Does the dome lamp illuminate normally?
YES : Go to Step 2.
NO : Refer to Inspection Procedure K-1 "The dome lamp
do not illuminate and go out normally P.54B-359."
STEP 2. Check the adjustment function.
Q: Has the dome lamp delay-off time been set to other than
"0 second" by the adjustment function?
YES : Go to Step 3.
NO : Set the dome lamp delay-off time to "0 second."