Page 390 of 1500

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-390
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 interior lamps.
If the interior lamp switch is moved to the "door interlock posi-
tion", the interior lamps should illuminate when either door is
opened.
Q: Do the interior lamp illuminate normally?
All the interior lamps illuminate normally. : Go to Step 2.
None of the interior lamps illuminate normally. : Refer to
Inspection Procedure K-1 "The dome lamp do not
illuminate and go out normally P.54B-359."
Some of the interior lamps do not illuminate normally. :
Refer to Inspection Procedure K-2 "The front dome
lamp, rear dome lamp or trunk lamp do not illuminate
or go out normally P.54B-366."
STEP 2. Check the adjustment function.
Q: Has a setting other than "No auto-shutoff" been
selected for the interior lamp automatic shutdown
function by the adjustment function?
YES : Go to Step 3.
NO : Set the interior lamp automatic shutdown function to
another setting other than "No auto-shutoff".
Page 414 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-414
CIRCUIT OPERATION
The ETACS-ECU operates the following functions or
systems according to signal from the front door
switches:
Light reminder tone alarm function
switch (RH)>
Door ajar warning buzzer
Forgotten key reminder
Power window timer function
Sunroof timer function
Keyless entry system
Timed locking mechanism
Headlamp automatic shutdown function
door switch (RH)>
Dome lamp
Interior lamp automatic-shutdown function
Ignition key hole illumination lamp
switch (RH)>
Door-ajar indicator lamp
.
TECHNICAL DESCRIPTION (COMMENT)
If the signal is not normal, the functions or systems
described in "CIRCUIT OPERATION" do not work
normally. If the signal is not normal, the front door
switches or the ETACS-ECU may be defective.
.
TROUBLESHOOTING HINTS
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
The front door switches may be defective
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 415 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-415
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 the input signal (by using the pulse check
mode of the monitor).
Check the input signals from the front door switches.
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 diagnostic tool MB991958.Refer to "How to
connect SWS monitor P.54B-13."
(2) 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."
(3) Check that diagnostic tool MB991958 sounds.
Q: Does diagnostic tool MB991958 sound when each front
door is opened and closed?
When the front door (RH) is opened and closed,
diagnostic tool MB991958 does not sound. : Go to Step
2.
When the front door (LH) is opened and closed,
diagnostic tool MB991958 does not sound. : Go to Step
7.
When either front door is opened and closed, diagnostic
tool MB991958 sounds. : Replace the ETACS-ECU. If the
functions described in "CIRCUIT OPERATION" work
normally, the input signal from the front door switches
should be normal.
STEP 2. Check front door switch (RH) connector D-34 for
loose, corroded or damaged terminals, or terminals
pushed back in the connector.
Q: Is front door switch (RH) connector D-34 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. If the functions described in "CIRCUIT
OPERATION" work normally, the input signal from the
front door switch (RH) should be normal.
Page 417 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-417
STEP 6. Check the wiring harness between front door
switch (RH) connector D-34 (terminal 1) and ETACS-ECU
connector C-219 (terminal 10).
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 front door switch (RH)
connector D-34 (terminal 1) and ETACS-ECU connector
C-219 (terminal 10) in good condition?
YES : Replace the ETACS-ECU. If the functions described
in "CIRCUIT OPERATION" work normally, the input
signal from the front door switch (RH) should be
normal.
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. If the
functions described in "CIRCUIT OPERATION" work
normally, the input signal from the front door switch
(RH) should be normal.
Page 440 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-440
INSPECTION PROCEDURE N-3: ETACS-ECU does not receive any signal from any of the door
switches.
.
CIRCUIT OPERATION
The ETACS-ECU operates the following functions or
systems according to signal from the front or rear
door switches:
Light reminder tone alarm function
switch (RH)>
Door ajar warning buzzer
Ignition key reminder tone alarm
switches>
Power window timer function
switches>
Sunroof timer function
Headlamp automatic shutdown function
door switch (RH)>
Keyless entry system
Timer lock
Dome lamp
Interior lamp automatic-shutdown function
door switches>
Ignition key hole illumination lamp
switch (RH)>
Door-ajar indicator lamp
.
TECHNICAL DESCRIPTION (COMMENT)
If the signal is not normal, the functions or systems
described in "CIRCUIT OPERATION" do not work
normally. If the signal is not normal, the front or rear
door switches or the ETACS-ECU may be defective.
.
TROUBLESHOOTING HINTS
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
The front or rear door switches may be defective
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
Page 441 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-441
STEP 1. Check the input signal (by using the pulse check
mode of the monitor).
Check the input signals from the all door switches.
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 diagnostic tool MB991958. Refer to "How to
connect SWS monitor P.54B-13."
(2) 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."
(3) Check that diagnostic tool MB991958 sounds.
Q: When the front and rear doors are opened/closed, does
the diagnostic tool MB991958 sound?
When the front doors are opened and closed, diagnostic
tool MB991958 does not sound. : Refer to Inspection
Procedure M-4 "ETACS-ECU does not receive any
signal from the front door switches P.54B-413."
When the rear door (LH) is opened and closed,
diagnostic tool MB991958 does not sound. : Go to Step
2.
When the rear door (RH) is opened and closed,
diagnostic tool MB991958 does not sound. : Go to Step
7.
STEP 2. Check rear door switch (LH) connector D-16 for
loose, corroded or damaged terminals, or terminals
pushed back in the connector.
Q: Is rear door switch (LH) connector D-16 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. If the functions described in "CIRCUIT
OPERATION" work normally, the input signal from the
rear door switch (LH) should be normal.
Page 443 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-443
STEP 6. Check the wiring harness between rear door
switch (LH) connector D-16 (terminal 1) and ETACS-ECU
connector C-219 (terminal 7).
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 door switch (LH)
connector D-16 (terminal 1) and ETACS-ECU connector
C-219 (terminal 7) in good condition?
YES : Replace the ETACS-ECU. If the functions described
in "CIRCUIT OPERATION" work normally, the input
signal from the rear door switch (LH) should be
normal.
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. If the
functions described in "CIRCUIT OPERATION" work
normally, the input signal from the rear door switch
(LH) should be normal.
Page 446 of 1500
INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-446
INSPECTION PROCEDURE N-4: ETACS-ECU does not receive any signal from the door lock key
cylinder switch.
.
CIRCUIT OPERATION
The ETACS-ECU operates the central door locking
system according to signal from the door lock key
cylinder switch.
.
TECHNICAL DESCRIPTION (COMMENT)
If the signal is not normal, the systems, which are
described in "CIRCUIT OPERATION", do not work
normally.
.
TROUBLESHOOTING HINTS
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
The door lock key cylinder switch may be defec-
tive
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