GENERAL DESCRIPTION
SIMPLIFIED WIRING SYSTEM (SWS)54B-5
INTERMITTENT CONTROL
ETACS-ECU uses the dial position of the variable
intermittent wiper control switch and the vehicle
speed signal sent by the combination meter to calcu-
late the interval to be sent to the front-ECU. The
front-ECU determines the intermittent time from the
input SWS data signal, and turns ON the windshield
wiper drive signal. When the wiper is at the STOP
position, the windshield wiper auto-stop signal goes
OFF to turn OFF the windshield wiper drive signal.
After the intermittent time from when the windshield
wiper drive signal turned ON, the windshield wiper
drive signal is turned ON again and the above opera-
tion is repeated.
.
MIST WIPER CONTROL
When the ignition switch is in the ACC or ON posi-
tion, and the windshield mist wiper switch of the col-
umn switch is turned ON, the front-ECU turns ON the
windshield wiper drive signal. At the same time, the
wiper speed switching relay is turned ON
(HIGH-SPEED). While the windshield mist wiper
switch is ON, the windshield wiper will operate at
high speed. Then, if the windshield mist wiper switch
is turned off, the wiper operates at low speed until it
stops at the predetermined park position.
When the windshield mist switch is turned on briefly,
the wiper operates once at low speed.
At the point the windshield mist switch is turned ON,
if the windshield wiper has been operating intermit-
tently, the same operations as the above will be per-
formed while the windshield mist wiper switch is ON.
After the windshield mist wiper switch goes OFF, the
intermittent operations will be set again after the
windshield wiper auto-stop signal last is turned ON.
.
WASHER CONTROL
When the ignition switch is in the ACC or ON posi-
tion, and the windshield washer switch of the column
switch is turned ON, the front-ECU turns ON the
windshield washer relay. The windshield wiper drive
signal is turned ON in 0.15 seconds until 2 seconds
after the windshield washer switch goes OFF to
operate the windshield wiper continuously. When the
windshield washer switch is turned ON, if the wind-
shield wiper is operating intermittently, intermittent
operations will be continued after continuous opera-
tions.
HEADLAMP
.
HEADLAMP AUTOMATIC SHUTDOWN
FUNCTION
Even if the lighting switch (tail lamp switch or
headlamp switch) is ON, the headlamps and tail
lamps will automatically go off in the following condi-
tions to prevent the battery from discharging:
When the ignition key is turned from "ON" to "LOCK"
(OFF) or "ACC" position with the lighting switch
turned ON, and this state continues for three min-
utes, the lamp will automatically be turned off. If the
driver's seat door is opened during these three min-
utes, the lamp will go off one second later.
.
HIGH-BEAM INDICATOR
At the same time that the high beams are illumi-
nated, the ETACS-ECU sends a signal to illuminate
the high-beam indicator via the CAN bus line. The
combination meter receives the transmitted signal
and turns the high-beam indicator on and off.
FLASHER TIMER
.
TURN-SIGNAL LAMP
The turn-signal lamp output (flashing signal) is
turned ON when the ignition switch is ON and the
turn-signal lamp switch is ON (LH or RH). If the front
turn-signal lamp or rear turn-signal lamp bulb has
burned out, the flashing speed increases to indicate
that the bulb has burned out.
.
HAZARD WARNING LAMP
Detects the signal where the hazard warning lamp
switch input changes from OFF to ON, and reverse
the flashing state according to this signal. The haz-
ard warning lamps toggle on and off whenever the
hazard warning lamp switch is operated.
.
TURN-SIGNAL INDICATORS
At the same time that the turn-signal lamps are illu-
minated, the ETACS-ECU sends a signal to illumi-
nate the turn-signal lamp indicator via the CAN bus
line. The combination meter receives the transmitted
signal and turns the turn-signal lamp indicator on and
off.
SWS DIAGNOSIS
SIMPLIFIED WIRING SYSTEM (SWS)54B-17
ETACS
NOTE: For item No.43, the diagnostic tool
MB991958 (MUT-III Sub Assembly) also displays
"ON" when the lamp reminder tone alarm or the seat
belt tone alarm function is triggered.
.
CHECK
ITEMITEM NO. DISPLAY ON
DIAGNOSTIC
TOOLCHECK CONDITION NORMAL
CONDITION
Tone alarm 43 BUZZER When requirements for sounding each
warning tone alarm are not satisfiedOFF
Front fog
lamps36 F.FOG LAMP
1. Lighting switch: HEAD
2. Fog lamp switch: ONON
Other than the condition above OFF
Driver’s door
switch32 FRONT DOOR
SWDriver’s door switch and Front passenger’s
door switch is on ON
Driver’s door switch and Front passenger’s
door switch is offOFF
Headlamp
automatic
shutoff
function35 H/L AUTO-CUT
1. Lighting switch: Other than OFF
2. Ignition switch: from ON or START to
LOCK (OFF) or ACC
3. Front door switch: ON (front door open) OFF to ON (after
approximately one
second)
When requirements for the headlamp
automatic shutoff are not satisfiedOFF
Ignition
switch (ACC)31 IG SW (ACC) Ignition switch: ACC or ON ON
Ignition switch: LOCK (OFF) or START OFF
Ignition
switch (IG1)30 IG SW (IG1) Ignition switch: ON or START ON
Ignition switch: LOCK (OFF) or ACC OFF
Windshield
intermittent
wiper interval37 INT WIPE
TIME1. Ignition switch: ACC or ON
2. Operate the intermittent wiper control,
and change the wiper intervalThe diagnostic tool
MB991958
(MUT-III Sub
Assembly)
displays
intermittent wiper
interval in
response to the
intermittent wiper
control positions.
SYMPTOM CHART
SIMPLIFIED WIRING SYSTEM (SWS)54B-57
SYMPTOM CHARTM1549000801159
ECU COMMUNICATION SYSTEM
FUNCTION SYSTEM
SYMPTOM INSPECTION
PROCEDUREREFERENCE
PA G E
Communication with the SWS monitor kit is not possible. A-1
P.54B-63
Communication with the column switch (column-ECU) is not possible. A-2
P.54B-68
Communication with the ETACS-ECU is not possible. A-3
P.54B-74
Communication with the front-ECU is not possible. A-4
P.54B-80
Communication with the sunroof-ECU is not possible. A-5
P.54B-87
SYSTEM SYMPTOM INSPECTION
PROCEDUREREFERENCE
PA G E
Tone alarm General description concerning the tone alarm
P.54B-94
Light reminder tone alarm function does not work
normally.B-2
P.54B-98
Seat belt tone alarm function does not work
normally.B-3
P.54B-101
Door ajar warning buzzer function does not work
normally.B-4
P.54B-106
The multi center display does not sound normally
when it is operated.
P.54B-112
Turn-signal lamp buzzer function does not work
normally.B-6
P.54B-116
Central door locking
systemGeneral description concerning central door
locking system
P.54B-118
The central door locking system does not work at
all.C-1
P.54B-122
Some doors do not lock or unlock. C-2
P.54B-129
All the doors do not lock or unlock with just the
door lock switch operation.C-3
P.54B-142
All the doors do not lock or unlock with just the
door lock key cylinder key operation.C-4
P.54B-143
Forgotten key prevention function does not work
normally.C-5
P.54B-144
SYMPTOM CHART
SIMPLIFIED WIRING SYSTEM (SWS)54B-59
Headlamp and
taillampGeneral description concerning the headlamp and
taillampP.54B-257
The taillights do not illuminate normally. H-1
P.54B-260
The headlamps (low-beam) do not illuminate
normally.H-2
P.54B-264
The headlamps (high-beam) do not illuminate
normally.H-3
P.54B-268
When the passing switch is turned "ON," the
headlamps (low-beam or high-beam) do not
illuminate.H-4
P.54B-271
Headlights do not illuminate when the lighting
switch is at "TAIL," and "PASSING" position, but
illuminate at low-beam when the switch is at
"HEAD" position. At this position, the headlamps
cannot be changed to high beam by operating the
dimmer switch.H-5
P.54B-273
The taillamps, the position lamps, front parking
lamps or the license plate lamp do not illuminate.H-6
P.54B-275
One of the headlamps does not illuminate. H-7
P.54B-290
The high-beam indicator lamp does not illuminate. H-8
P.54B-301
Headlamp automatic shutoff function does not
work normally.H-9
P.54B-305
Headlamp dimmer switch automatic resetting
function does not work normally.H-10
P.54B-308
Flasher timer General description concerning the flasher timer
P.54B-309
Turn-signal lamps do not flash when the
turn-signal lamp switch is turned on.I-1
P.54B-310
Hazard warning lamps do not flash when the
hazard warning lamp switch is turned on.I-2
P.54B-314
One of the turn-signal lamps does not illuminate. I-3
P.54B-316
The turn-signal lamp indicator does not illuminate
normally.I-4
P.54B-335
Fog lamp General description concerning the fog lamps
P.54B-339
Fog lamps do not illuminate when the fog lamp
switch is turned on.J-1
P.54B-340
Fog lamps do not go out when the headlamps
(low-beam) are turned off while the fog lamps are
on.J-2
P.54B-345
One of the fog lamps does not illuminate. J-3
P.54B-345
The fog lamp indicator does not illuminate
normally.J-4
P.54B-350 SYSTEM SYMPTOM INSPECTION
PROCEDUREREFERENCE
PA G E
SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-94
NOTE: Also check intermediate connector C-27 for loose, cor-
roded, or damaged terminals, or terminals pushed back in the
connector. If intermediate connector C-27 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 sunroof motor assembly
connector D-04 (terminal 10) and ETACS-ECU connector
C-218 (terminal 53) in good condition?
YES : Go to Step 10.
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. The system
should communicate with the sunroof-ECU normally.
STEP 10. Replace the sunroof motor assembly.
(1) Replace the sunroof motor assembly.
(2) The system should communicate with the sunroof-ECU
normally.
Q: Can the system communicate with the sunroof-ECU?
YES : No action is necessary and testing is complete.
NO : Replace the ETACS-ECU. The system should
communicate with the sunroof-ECU normally.
TONE ALARM
GENERAL DESCRIPTION CONCERNING THE TONE ALARMM1549021000326
The tone alarm functions are as follows. These func-
tions are controlled by relevant ECUs.
FUNCTION CONTROL ECU
Light reminder tone alarm function ETACS-ECU, column switch
Seat belt tone alarm function ETACS-ECU
Door ajar warning buzzer ETACS-ECU
Center display operation tone
Turn-signal lamp buzzer ETACS-ECU, column switch
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
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
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.
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
Door ajar warning buzzer
Forgotten key reminder
Power window timer function
Sunroof timer function
Keyless entry system
Timed locking mechanism
Headlamp automatic shutdown function
Dome lamp
Interior lamp automatic-shutdown function
Ignition key hole illumination lamp
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