SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-96
If any of the following conditions is met with the igni-
tion switch at "ON" or "ST", the ETACS-ECU sounds
the tone alarm by using the driver's seat belt switch
signal and the vehicle speed signal sent from the
combination meter.
Sounds the tone alarm for six seconds when the
ignition switch is turned "ON" with the seat belt
switch on (the driver's seat belt is not fastened).
This is called "Timer function".
Sounds the tone alarm 12 cycles (after 0.5 sec-
onds) if any of the following conditions is met
when sixty seconds or more have elapsed since
the ignition switch is turned "ON". One cycle con-
sists of five-second "on" and then three-second
"off".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 the tone alarm has sounded 12
cycles, it does not sound again until the vehi-
cle speed reduces to 3 km/h (2 mph) or less
even if any of the following conditions is met.
The tone alarm stops sounding 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.
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
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
SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-111
STEP 6. Check the input signal (by using the pulse check
mode of the monitor).
Check the following switches and input signals:
Doors switches
(1) 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."
(2) Check if diagnostic tool MB991958 sounds or not.
Q: When any door switch is operated, does diagnostic tool
MB991958 sound?
YES : Replace the ETACS-ECU. The door ajar warning
buzzer function should now work normally.
NO : Refer to Inspection Procedure N-3 "ETACS-ECU
does not receive any signal from any of the door
switches P.54B-440." ITEM NAME CONDITION
door switch Open or close one of the doors
SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-112
INSPECTION PROCEDURE B-5: Tone Alarm: The Multi center Display does not Sound Normally When
it is Operated.
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 sounds the buzzer when it
receives buzzer signal from the multi center display
(MID).
.
TECHNICAL DESCRIPTION (COMMENT)
If this function does not work normally, connector(s),
wiring harness in the CAN bus lines, the mid-
dle-grade multi center display unit or the
ETACS-ECU may be defective.
.
TROUBLESHOOTING HINTS
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
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
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 operation of the multi center display
(MID).
Q: Does the multi center display work normally?
YES : Go to Step 2.
NO : First, replace the multi center display unit.
SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-115
STEP 5. Check the input signal by using "FUNCTION
DIAG." menu of the SWS monitor.
Turn the ignition switch to the "ON" position to check the input
signals from the following switches.
(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: If the function switch of the multi center display is
operated, check that No.43 "BUZZER" is displayed as nor-
mal condition.
Q: Are normal conditions displayed for the "IG SW (IG1)"
and "BUZZER"?
Normal conditions are displayed for all the items :
Replace the ETACS-ECU. Verify that the multi center
display operating sound 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 multi center
display operating sound function works normally. ITEM NO. ITEM NAME NORMAL
CONDITION
ITEM 30 IG SW (IG1) ON
ITEM 43 BUZZER ON
SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-142
INSPECTION PROCEDURE C-3: Central Door Locking System: All the Doors do not Lock or Unlock
with just the Door Lock Switch Operation.
.
TECHNICAL DESCRIPTION (COMMENT)
The door lock switch (incorporated in the power win-
dow main switch and front power window sub switch)
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
Check the input signal (by using the pulse check mode of
the monitor).
Check the input signals from the door lock switch (incorporated
in the power window main switch and front power window sub
switch):
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 special tool. Refer to "How to connect SWS
monitor P.54B-13."
(2) When the driver's or the front passenger's door lock switch
is moved from "LOCK" to "UNLOCK" and vice versa, check
if diagnostic tool MB991958 sounds or not.
(3) 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."
Q: Does diagnostic tool MB991958 sound when the driver's
or the front passenger's door lock switch is moved from
"LOCK" to "UNLOCK" and vice versa?
YES : Replace the ETACS-ECU. Check that all the doors
should be locked and unlocked by the door lock
switch.
NO : Refer to Inspection Procedure N-6 "ETACS-ECU
does not receive any signal from the door lock switch
(incorporated in the power window main switch and
front power window sub switch) P.54B-460."
SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-143
INSPECTION PROCEDURE C-4: Central Door Locking System: All the Doors do not Lock or Unlock
with just the Door Lock Key Cylinder Key Operation.
.
TECHNICAL DESCRIPTION (COMMENT)
The door lock key cylinder switch 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
Check the input signal (by using the pulse check mode of
the monitor).
Check the input signals from the door lock key cylinder switch.
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 special tool. Refer to "How to connect SWS
monitor P.54B-13."
(2) When the doors are locked and unlocked by using the
driver's door lock key cylinder, check that diagnostic tool
MB991958 sounds.
(3) 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."
Q: When the doors are locked and unlocked by using the
driver's door lock key cylinder, does diagnostic tool
MB991958 sound?
YES : Replace the ETACS-ECU. Check that all the doors
should be locked and unlocked by using driver door
lock key cylinder switch.
NO : Refer to Inspection Procedure N-4 "ETACS-ECU
does not receive any signal from the door lock key
cylinder switch P.54B-446."
SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-147
STEP 3. Check the input signal (by using the pulse check
mode of the monitor).
Check the following switches and input signals:
Key reminder switch
Door switches
(1) 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."
(2) Check if diagnostic tool MB991958 sounds or not.
Q: When the key reminder switch, any door switch is
operated, does diagnostic tool MB991958 sound?
Buzzer of diagnostic tool MB991958 sounds normally. :
Replace the ETACS-ECU. The forgotten key
prevention function should work normally.
When the ignition key is removed and inserted,
diagnostic tool MB991958 does not sound. : Refer to
Inspection Procedure N-1 "ETACS-ECU does not
receive any signal from the key reminder switch
P.54B-432."
When one of the doors is opened and closed,
diagnostic tool MB991958 does not sound : Refer to
Inspection Procedure N-3 "ETACS-ECU does not
receive any signal from any of the door switches
P.54B-440." ITEM NAME CONDITION
key reminder switch Remove and reinsert the ignition key
Door switches Open or close one of the doors