Page 97 of 1500

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-97
Door ajar warning buzzer
The buzzer is sounded 4 times by the ETACS-ECU to warn the
driver if any door is open when the ignition is switched ON and
the vehicle speed reaches 8 km/h (5 mph) or faster. The buzzer
will continue to sound for 4 times even if the ignition, door sta-
tus, or vehicle speed requirements are not maintained.
NOTE: The warning buzzer can be customized on vehicles
equipped with a multi center display. Refer to P.54B-486.
Multi center display operation tone
center display >
The ETACS-ECU sounds the buzzer when the buzzer signal is
sent from the center display.
Turn-signal lamp buzzer
The ETACS-ECU sounds the buzzer in sync with the turn-sig-
nal lamps or hazard warning lamps.
NOTE: The turn-signal lamp buzzer can be customized on
vehicles equipped with a multi center display (middle grade
type). Refer to P.54B-486.
General circuit diagram for lamp reminder tone alarm function. P.90-111
General circuit diagram for seat belt tone alarm function. P.90-113
Page 101 of 1500

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-101
Normal condition is not displayed for "FRONT DOOR
SW" : Refer to Inspection Procedure M-4 "ETACS-ECU
does not receive any signal from the front door
switches P.54B-413."
Normal condition is not displayed for "H/L AUTO-CUT" :
Refer to Inspection Procedure H-9 "Headlamp
automatic shutoff function does not work normally
P.54B-305."
Normal condition is not displayed for "BUZZER" :
Replace the ETACS-ECU. The lamp reminder tone
alarm function should now work normally.
INSPECTION PROCEDURE B-3: Tone Alarm: Seat Belt Tone Alarm 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."
.
CIRCUIT OPERATION
The ETACS-ECU receives the driver's seat belt
switch ON signal from the ignition switch (IG1) and
the combination meter, and then controls the seat
belt tone alarm function.
The ETACS-ECU operates the seat belt tone alarm
function under the following conditions:
Ignition switch: "ON" position
Driver's seat belt: Unfastened
.
TECHNICAL DESCRIPTION (COMMENT)
If the seat belt tone alarm does not work, connec-
tor(s), wiring harness in the CAN bus lines, the com-
bination meter, the ETACS-ECU or the input signal
circuit 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 105 of 1500

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-105
STEP 4. Check the input signal by using "FUNCTION
DIAG." menu of the SWS monitor.
Check the input signals from the following switches:
Ignition switch: OFF ON
Driver's seat belt: Unfastened
All door: Closed
(1) Operate diagnostic tool MB991958 according to the
procedure below to display "OTHER ALARM"
a. Select "Interactive Diagnosis."
b. Select "System Select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "Function Diag."
f. Select "BUZZER."
g. Select "OTHER ALARM"
(2) Check that normal conditions are displayed for the items
described in the table below.
NOTE: Turn the ignition switch from the OFF position to the
ON position. Then item No.43 should be ON for approxi-
mately six seconds only.
Q: Does diagnostic tool MB991958 display the items "IG
SW (IG1)" and "BUZZER" as normal condition?
Normal conditions are displayed for all the items :
Replace the ETACS-ECU. Verify that the seat belt
tone alarm function works normally.
Normal condition is not displayed for "IG SW (IG1)" :
Refer to Inspection Procedure M-2 "ETACS-ECU
does not receive any signal from the ignition switch
(IG1) P.54B-408."
Normal condition is not displayed for "BUZZER" :
Replace the ETACS-ECU. Verify that the seat belt
tone alarm function works normally. ITEM NO. ITEM NAME NORMAL CONDITION
ITEM 30 IG SW (IG1) ON
ITEM 43 BUZZER ON (for approximately six
seconds after the ignition
switch is turned from OFF
to ON), and then OFF
Page 355 of 1500

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-355
54B
INTERIOR LAMP
GENERAL DESCRIPTION CONCERNING THE INTERIOR LAMPM1549021800236
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80The following ECUs affect the functions and control
of the interior lamps.
Interior lamp control function
The ETACS-ECU controls the interior lamps by turn-
ing them on and off in the following way:
When a door is opened with the ignition switch
off, the interior lamps up to a luminance of 100
percent. When a door is closed, the interior lamps
dims at a luminance of 65 percent, and goes off
30 seconds later. However if the ignition switch is
turned ON or if a door is locked while the interior
lamps is dimming, the dome lamp will go off at
that point.
When a door is opened with the ignition switch
ON, the interior lamps up at a luminance of 100
percent. When a door is closed, the interior lamps
go off.
When the ignition key is removed with all doors
closed, the interior lamps up at a luminance of
100 percent, and goes off 30 seconds later. How-
ever if the ignition key is inserted again or if a
door is locked while the interior lamps is lighting,
the interior lamps will go off at that point.
To check keyless entry operations more easily,
the interior lamps is flashed once when the doors
are locked. When the doors are unlocked, the
interior lamps at a luminance of 100 percent, and
go off 15 seconds later.
NOTE: The dimmer function can be customised on
vehicles equipped with a multi center display (middle
grade type). Refer to P.54B-486.
NOTE: The dotted lines indicate that lighting mode
when the ignition switch is turned ON, door is locked,
or any door is opened during the timer illumination
time. FUNCTION CONTROL ECU
Interior lamp control function ETACS-ECU
Interior lamp automatic-shutoff function ETACS-ECU
Ignition key hole illumination lamp function ETACS-ECU
Door ajar indicator ETACS-ECU
Seat belt indicator ETACS-ECU
Page 357 of 1500
SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-357
Seat belt indicator
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SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-358
If any of the following conditions is met with the igni-
tion switch at "ON" or "ST", the ETACS-ECU illumi-
nates, flashes or extinguishes the seat belt indicator
by using the driver's seat belt switch signal and the
vehicle speed signal sent from the combination
meter.
Illuminates when the ignition switch is at "ON"
and the seat belt switch is turned on (the driver's
seat belt is unfastened).
Flashes and illuminates the indicator 12 cycles
(after 0.5 seconds) if any of the following condi-
tions is met when sixty seconds or more have
elapsed since the ignition switch is turned "ON".
One cycle consists of five-second "flashing" and
then three-second "illumination".a. The vehicle speed has reached 8 km/h (5
mph) while the seat belt switch is turned on
(driver's seat belt is not fastened) with the
ignition switch "ON.
b. The seat belt switch has been turned on
(driver's seat belt has not been fastened) for
at least ten seconds while the ignition switch
has been turned "ON" and the vehicle speed
has been 8 km/h (5 mph) or more.
NOTE: Once this timer operation has been acti-
vated, it will not be activated again until the
vehicle speed reduces to 3 km/h (2 mph) or
less even if any of the following conditions is
met.
The indicator stops illuminating if the ignition
switch or the seat belt switch is turned off (the
driver's seat belt is fastened) while the timer
operation is active.
Page 398 of 1500

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-398
INSPECTION PROCEDURE K-7: Interior Light: The seat belt warning lamp do not illuminate or 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 combination meter and the ETACS-ECU illumi-
nates and flashes the seat belt warning lamp by
using the signal from the seat belt switch, the ignition
switch (IG1) and the vehicle speed signal.
.
TECHNICAL DESCRIPTION (COMMENT)
If the seat belt warning lamp does not illuminate or
flash correctly, connector(s), wiring harness in the
CAN bus lines, the door switches, the ETACS-ECU,
or the combination meter 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 combination meter 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
Page 401 of 1500

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-401
STEP 4. Check the input signal by using "DATA LIST"
menu of the SWS monitor.
Check the input signals from the following switches:
Ignition switch: ON
(1) Operate diagnostic tool MB991958 according to the
procedure below to display "ETACS ECU."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "Data List."
f. Select "ETACS ECU."
(2) Check that normal conditions are displayed for the items
described in the table below.
Q: Is the diagnostic tool MB991958 display the items "IG
SW (IG1)" normal condition?
YES : Go to Step 5.
NO : Refer to Inspection Procedure M-2 "ETACS-ECU
does not receive any signal from the ignition switch
(IG1) P.54B-408."
STEP 5. Replace the combination meter.
(1) Replace the combination meter.
(2) Check that the seat belt warning lamp illuminates normally.
Q: Is the seat belt warning lamp in good condition?
YES : No action is necessary and testing is complete.
NO : Replace the ETACS-ECU. Verify that the seat belt
warning lamp illuminates normally. ITEM NO. ITEM NAME NORMAL CONDITION
ITEM 30 IG SW (IG1) ON