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.
SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-345
INSPECTION PROCEDURE J-2: Fog Light: Fog lamps do not go out when the headlamps (low-beam)
are turned off while the fog lamps are on.
.
TECHNICAL DESCRIPTION (COMMENT)
If the trouble above occurs, the front-ECU may be
defective.
.
TROUBLESHOOTING HINT
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
The front-ECU may be defective
DIAGNOSIS
Replace the front-ECU.
The fog lamps should go out when the headlamps (low-beam)
are turned off while the fog lamps are on.
INSPECTION PROCEDURE J-3: Fog Light: One of the fog lamps does not illuminate.
.
TECHNICAL DESCRIPTION (COMMENT)
If one of the fog lamps does not illuminate, the fog
lamp relay or the fog lamp bulb may be defective. If
the fog lamp indicator lamp does not illuminate, the
combination meter may be defective.
.
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 fog lamp bulb may be defective
.
DIAGNOSIS
Required Special Tool:
MB991223: Harness Set
SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-359
INSPECTION PROCEDURE K-1: Interior Light: The dome lamp do not illuminate and 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 ETACS-ECU operates the dome lamp according
to the following signals:
Ignition switch (IG1): ON or OFF
Key reminder switch: ON or OFF
Door switches: ON or OFF
Driver’s door lock actuator switch: ON or OFF
Interior lamp loaded signal: ON
.
TECHNICAL DESCRIPTION (COMMENT)
If the dome lamp does not illuminate normally, a
burned-out dome lamp bulb, the input circuits from
the switches described in "CIRCUIT OPERATION",
the power supply line to the switches 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
SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-381
INSPECTION PROCEDURE K-4: Interior Light: The ignition key hole illumination lamp does 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
When the driver's door is opened with the ignition
switch at "ACC" position, the ETACS-ECU illumi-
nates the ignition key hole illumination lamp.
The ignition key hole illumination lamp goes out
in 30 seconds after the driver's door is closed.
The ignition key hole illumination lamp remains
illuminated for 30 seconds after the ignition key is
pulled out.
The ETACS-ECU operates the ignition key hole
illumination lamp according to the input signals
from the following switches:
Ignition switch (IG1): OFF
Key reminder switch: OFF
Interior lamp loaded signal: ON
Vehicle condition:
Ignition switch: "LOCK" (OFF) or "ACC" posi-
tion
Ignition key: Removed from the ignition key
cylinder
Driver’s door: Opened or closed
.
TECHNICAL DESCRIPTION (COMMENT)
If the ignition key hole illumination lamp does not illu-
minate, the input circuits from the switches described
in "CIRCUIT OPERATION", the key reminder switch
(ignition key hole illumination lamp bulb) 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
HOW TO DIAGNOSE
GENERAL
INSPECTION INSTRUMENTSM1001004700040
For inspection, use the following instruments:
Never use a test light for checking ECU-related circuits or
ECUs.
1. Test light
A test light consists of a 12V bulb and lead wires. It is used
to check voltages or short circuits.
2. Self-powered test light
A self-powered test light consists of a bulb, battery and lead
wires connected in series. It is used to check continuity or
grounding.
Never use a jumper wire to connect a power supply
directly to a load.
3. Jumper wire
A jumper wire is used to close an open circuit.
4. Voltmeter
A voltmeter is used to measure the circuit voltage. Normally,
the positive (red lead) test probe is applied to the point of
voltage measurement and the negative (black lead) test
probe to the body ground. Use a digital voltmeter to check
for voltage drop before or after a component.
CHARGING SYSTEM
ENGINE ELECTRICAL16-3
CHARGING SYSTEM DIAGNOSISM1161000700427
TROUBLESHOOTING HINTS
Alternator malfunction light dose not go on when the ignition
switch is turned to ON, before the engine starts.
Check the bulb.
Alternator malfunction light dose not switch off after the engine
starts.
Check the IC voltage regulator inside the
alternatoralternator.
Discharged or overcharged battery.
Check the IC voltage regulator inside the alternator.
The alternator malfunction light illuminates dimly.
Check the diode (inside the combination meter) for a
short-circuit.
TROUBLESHOOTING GUIDE
The charging system troubleshooting guide is shown in the fol-
lowing steps.
STEP 1.
Q: Is the battery in good condition? (Refer to GROUP 54A,
Chassis Electrical
Battery On-vehicle Service
Battery Check P.54A-5.)
YES : Go to Step 2.
NO : Charge or replace the battery.
STEP 2.
Q: Is the alternator drive belt in good condition? (Refer to
GROUP 00, General
Maintenance Service Drive Belts
(For Alternator, Power Steering Pump and Air
Conditioning) (Check) P.00-39.)
YES : Go to Step 3.
NO : Adjust the belt tension or replace the belt.
STEP 3.
Q: Does the alternator malfunction light come on when the
ignition switch is turned on?
YES : Go to Step 4.
NO :
Check the ignition switch. (Refer to GROUP 54A,
Chassis Electrical
Ignition Switch Ignition
Switch
Inspection P.54A-44.)
Check for burnt-out alternator malfunction light.
Check the alternator. (Refer to Charging System
Alternator Assembly
Inspection P.16-17.)
Check the alternator malfunction light-related
circuits.
TRACTION CONTROL SYSTEM (TCL) DIAGNOSIS
TRACTION CONTROL SYSTEM (TCL)13C-24
.
CIRCUIT OPERATION
The TCL automatically goes to ON, when the
ignition is turned to the "ON" position. To deacti-
vate the TCL, press the TCL switch. To reactivate
the TCL , press the TCL switch again.
ABS/TCL-ECU send the illumination signal of
"TCL OFF" indicator light and TCL work indicator
light to the combination meter via the CAN com-
munication.
ABS/TCL-ECU operates the "TCL OFF" indicator
light and the TCL work indicator light for three
seconds after the ignition switch is turned "ON"
position for bulb check.