Page 438 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-438
STEP 4. Check the wiring harness between hazard warning
lamp switch connector C-08 (terminal 2) and ground.
Q: Is the wiring harness between hazard warning lamp
switch connector C-08 (terminal 2) and ground 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. If the
equipment described in "CIRCUIT OPERATION" work
normally, the input signal from the hazard warning
lamp switch should be normal.
STEP 5. Check ETACS-ECU connector C-218 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is ETACS-ECU connector C-218 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. If the equipment described in "CIRCUIT
OPERATION" work normally, the input signal from the
hazard warning lamp switch should be normal.
Page 439 of 1500
INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-439
STEP 6. Check the wiring harness between hazard warning
lamp switch connector C-08 (terminal 1) and ETACS-ECU
connector C-218 (terminal 49).
Q: Is the wiring harness between hazard warning lamp
switch connector C-08 (terminal 1) and ETACS-ECU
connector C-218 (terminal 49) in good condition?
YES : Replace the ETACS-ECU. If the equipment described
in "CIRCUIT OPERATION" work normally, the input
signal from the hazard warning lamp switch 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
equipment described in "CIRCUIT OPERATION" work
normally, the input signal from the hazard warning
lamp switch 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 442 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-442
STEP 3. Check the rear door switch (LH).
Remove the rear door switch (LH). Refer to GROUP 42, Door,
Door Assembly P.42-37. Then check continuity between the
switch terminals and the body ground.
Q: Is the rear door switch (LH) in good condition?
YES : Go to Step 4.
NO : Replace the rear door switch (LH). If the functions
described in "CIRCUIT OPERATION" work normally,
the input signal from the rear door switch (LH) should
be normal.
STEP 4. Measure resistance at the lower metal part of the
rear door switch (LH) in order to check the ground circuit
to the rear door switch (LH).
NOTE: Check that the rear door switch (LH) is grounded to the
vehicle body via its mounting screw.
Remove the cap, and measure the resistance value between
the lower metal part and ground.
The resistance should be 2 ohms or less.
Q: Is the measured resistance 2 ohms or less?
YES : Go to Step 5.
NO : Check the installation of the switch, and repair if
necessary. If the functions described in "CIRCUIT
OPERATION" work normally, the input signal from the
rear door switch (LH) should be normal.
STEP 5. Check ETACS-ECU connector C-219 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is ETACS-ECU connector C-219 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. If the functions described in "CIRCUIT
OPERATION" work normally, the input signal from the
rear door switch (LH) should be normal. SWITCH
POSITIONTESTER
CONNECTIONSPECIFIED
CONDITION
Released (ON) 1
body ground Less than 2 ohms
Pressed (OFF) 1
body ground Open circuit
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 445 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-445
STEP 10. 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 11.
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 (RH) should be normal.
STEP 11. Check the wiring harness between rear door
switch (RH) connector D-06 (terminal 1) and ETACS-ECU
connector C-217 (terminal 35).
Q: Is the wiring harness between rear door switch (RH)
connector D-06 (terminal 1) and ETACS-ECU connector
C-217 (terminal 35) 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 (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 rear door switch
(RH) 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