Page 408 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-408
INSPECTION PROCEDURE M-2: ETACS-ECU does not receive any signal from the ignition switch
(IG1).
.
CIRCUIT OPERATION
The ETACS-ECU operates the following equipment
or functions according to signal from the ignition
switch (IG1):
Light reminder tone alarm function
Seat belt tone alarm function
Door ajar warning buzzer
Turn-signal lamp buzzer
Multi center display operation tone
multi center display (middle grade type)>
Power window timer function
Sunroof timer function
Headlamp automatic shutdown function
Turn-signal lamp
Dome lamp dimming function
Ignition key hole illumination lamp
If the power supply circuit from the battery to the
ETACS-ECU is open, this circuit is used as
backup circuit.
If the signal is not normal, the equipment or functions
described in "CIRCUIT OPERATION" do not work
normally.
The ETACS-ECU receives information on the ignition
switch condition (IG1) from the combination meter
via CAN communication. If the ignition switch (IG1)
input signal is incorrect, refer to the Diagnostic Trou-
ble Code Chart P.54B-25.
.
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 ETACS-ECU may be defective
DIAGNOSIS
Required Special Tool:
MB991223: Harness Set
STEP 1. 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 2.
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
ignition switch (IG1) should be normal.
Page 411 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-411
CIRCUIT OPERATION
The ETACS-ECU operates the fog lamps according
to signal from the fog lamp switch.
.
TECHNICAL DESCRIPTION (COMMENT)
If the signal is not normal, the fog lamps do not work
normally. If the signal is not normal, the fog lamp
switch or the ETACS-ECU may be defective.
.
TROUBLESHOOTING HINTS
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
The fog lamp switch 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 Tool:
MB991223: Harness Set
STEP 1. Check fog lamp switch connector C-128 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is fog lamp switch connector C-128 in good condition?
YES : Go to Step 2.
NO : Repair or replace the damaged component(s). Refer
to GROUP 00E, Harness Connector Inspection
P.00E-2. Repair the fog lamp switch. If the fog lamp
switch operates normally, a correct signal is sent from
the fog lamp switch.
STEP 2. Check the fog lamp switch.
Remove the fog lamp switch. Refer to GROUP 54A, Fog lamp
P.54A-168. Then check continuity between the switch termi-
nals.
Q: Is the fog lamp switch in good condition?
YES : Go to Step 3.
NO : Repair the fog lamp switch. If the fog lamp switch
operates normally, a correct signal is sent from the
fog lamp switch.
SWITCH
POSITIONTESTER
CONNECTIONSPECIFIED
CONDITION
Released 1
2 Open circuit
Pressed 1
2 Less than 2 ohms
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 420 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-420
INSPECTION PROCEDURE M-5: Column Switch: ETACS-ECU does not receive any signal from the
taillamp switch, the headlamp switch, the passing lamp switch, the dimmer switch or the turn-signal
lamp switch.
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 following equipment
or functions according to signal from the column
switch (turn-signal lamp and lighting switch):
Light reminder tone alarm function
Turn-signal lamp buzzer
Headlamp
Turn-signal lamp
High-beam indicator
Turn-signal indicators
.
TECHNICAL DESCRIPTION (COMMENT)
If the signal is not normal, the equipment or functions
described in "CIRCUIT OPERATION" do not work
normally. If the signal is not normal, the column
switch (turn-signal lamp and lighting switch) or the
ETACS-ECU may be defective.
.
TROUBLESHOOTING HINTS
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
The column switch (turn-signal lamp and lighting
switch) 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 423 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-423
INSPECTION PROCEDURE M-6: Column switch: ETACS-ECU does not receive any signal from the
windshield mist wiper switch, the windshield intermittent wiper switch, the windshield low-speed
wiper switch, the windshield high-speed wiper switch or the windshield washer switch.
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 windshield wiper and
washer according to signal from the windshield wiper
and washer switch.
.
TECHNICAL DESCRIPTION (COMMENT)
If the signal is not normal, the windshield wiper and
washer do not work normally.
.
TROUBLESHOOTING HINTS
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
The column switch may be defective (windshield
wiper and washer switch)
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 426 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-426
INSPECTION PROCEDURE M-7: Column Switch: ETACS-ECU does not receive any signal from the
variable intermittent wiper control switch.
.
CIRCUIT OPERATION
The ETACS-ECU calculates the windshield intermit-
tent wiper interval according to the position of the
variable intermittent wiper control switch, which is
incorporated in column switch (windshield wiper and
washer switch).
.
TECHNICAL DESCRIPTION (COMMENT)
If the windshield intermittent wiper interval cannot be
adjusted, the column switch or the ETACS-ECU may
be defective.
.
TROUBLESHOOTING HINTS
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
The column switch may be defective (windshield
wiper and washer switch)
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 Tool:
MB991223: Harness Set
STEP 1. Check column switch connector C-309 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is column switch connector C-309 in good condition?
YES : Go to Step 2.
NO : Repair or replace the damaged component(s). Refer
to GROUP 00E, Harness Connector Inspection
P.00E-2. If the wiper interval can be adjusted
normally, the variable intermittent wiper control switch
should send a signal to the ECU.
Page 429 of 1500
INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-429
INSPECTION PROCEDURE M-8: Sunroof Switch: ETACS-ECU does not receive any signal from the
up, open or close/down switch.
.
CIRCUIT OPERATION
The ETACS-ECU receives a signal through the sun-
roof motor assembly via the SWS communication
line from the sunroof switch, and sends a signal to
the data link connector.
.
TECHNICAL DESCRIPTION (COMMENT)
If the SWS communication line between the sunroof
motor assembly and the ETACS-ECU is defective,
the ETACS-ECU cannot identify the input signal from
the sunroof switch even if the sunroof is normal.
.
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 sunroof motor assembly may be defective
The ETACS-ECU may be defective
Page 432 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-432
INSPECTION PROCEDURE N-1: ETACS-ECU does not receive any signal from the key reminder
switch.
.
CIRCUIT OPERATION
The ETACS-ECU operates the following functions or
systems according to signal from the key reminder
switch:
Forgotten key reminder
Keyless entry system
Timed locking mechanism
Dome lamp dimming function
Ignition key hole illumination lamp
.
TECHNICAL DESCRIPTION (COMMENT)
If the signal is not normal, the functions or systems
described in "CIRCUIT OPERATION" do not work
normally.
.
TROUBLESHOOTING HINTS
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
The key reminder switch 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 Tool:
MB991223: Harness Set
STEP 1. Check key reminder switch connector C-310 for
loose, corroded or damaged terminals, or terminals
pushed back in the connector.
Q: Is key reminder switch connector C-310 in good
condition?
YES : Go to Step 2.
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
key reminder switch should be normal.