SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-203
STEP 2. Check the input signal (by using the pulse check
mode of the monitor).
Check the input signals from the following switches:
Key reminder switch
Hazard warning lamp switch
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 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 the switches (see table below) applicable for the
input signal check are operated.
(4) Check diagnostic tool MB991958 sounds or not.
Q: When the key reminder switch and the hazard warning
lamp switch are operated, does diagnostic tool
MB991958 sound in each case?
Buzzer of diagnostic tool MB991958 sounds normally. :
Replace the ETACS-ECU. Verify that the encrypted
code can be registered in the transmitter.
diagnostic tool MB991958 does not sound when the
ignition key is removed and reinserted : Refer to
Inspection Procedure N-1 "ETACS-ECU does not
receive any signal from the key reminder switch
P.54B-432."
diagnostic tool MB991958 does not sound when the
hazard warning lamp switch is turned from "OFF" to
"ON" : Refer to Inspection Procedure N-2 "ETACS-ECU
does not receive any signal from the hazard warning
lamp switch P.54B-436." ITEM NAME CHECK CONDITION
Key reminder switch Remove and reinsert the
ignition key
Hazard warning lamp switch Turn the hazard warning lamp
switch from "OFF" to "ON"
position.
SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-205
INSPECTION PROCEDURE E-4: Keyless Entry System: The trunk is not opened when the keyless
entry transmitter "TRUNK" button is operated.
.
CIRCUIT OPERATION
A receiver is incorporated in the ETACS-ECU. This
receiver receives a lock or unlock signal from the
transmitter.
.
TROUBLESHOOTING HINTS
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
The RKE transmitter may be defective
The ETACS-ECU may be defective
The wiring harness or connectors may have
loose, corroded, or damaged terminals, or termi-
nals pushed back in the connector
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 that the doors can be locked and unlocked
by using the keyless entry transmitter.
Q: Can the doors be locked and unlocked normally when
the keyless entry transmitter is operated?
YES : Go to Step 2.
NO : Refer to Inspection Procedure E-1 "Keyless entry
system does not operate P.54B-191."
SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-259
Headlamp automatic-shutdown function
Even if the lighting switch (taillamps switch or headlamp switch)
is ON, the headlamps (including the taillamps) will automati-
cally go off in the following conditions to prevent the battery
from discharging as a result of forgetting to turn off lamps.
If 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 minutes, the headlamps will automati-
cally be turned off. If the driver's seat door is opened during
these three minutes, the headlamps will go off one second
later.
NOTE: The headlamp automatic-shutoff function can be cus-
tomized on vehicles equipped with a multi center display (mid-
dle grade type). Refer to P.54B-486.
Dimmer automatic reset function
If the headlamp switch is turned off while the high-beam
headlamps are on, the dimmer switch will be reset. Because of
this, the headlamps will illuminate at low beam the next time
that they are turned on. The dimmer switch will be also reset if
the dimmer switch is turned on unintentionally while the pass-
ing switch is operated.
SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-305
INSPECTION PROCEDURE H-9: Headlamp and Taillamp: Headlamp automatic shutoff function does
not work 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 headlamp automatic
shutdown function according to the following signals:
Ignition switch (IG1): OFF
Driver's door switch: ON
Taillamp switch: ON
Headlamp switch: ON
The ETACS-ECU operates the headlamp automatic
shutdown function under the following conditions:
Ignition key: Other than "ON" position
Driver's door: open
Taillamps or headlamps: on
.
TECHNICAL DESCRIPTION (COMMENT)
If the function does not work normally, the input cir-
cuit system from the switches, the ETACS-ECU or
the front-ECU may be defective (refer to "CIRCUIT
OPERATION").
.
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 front-ECU may be defective
SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-310
INSPECTION PROCEDURE I-1: Flasher Timer: Turn-signal lamps do not flash when the turn-signal
lamp switch is turned on.
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 turn-signal lamp switch sends a signal
through the column-ECU (incorporated in the col-
umn switch) to the ETACS-ECU. If the col-
umn-ECU sends a turn-signal lamp switch "ON"
signal to the ETACS-ECU, the ETACS-ECU turns
on the flasher timer (incorporated in the
ETACS-ECU), thus causing the turn-signal lamps
to flash.
The ETACS-ECU operates the turn-signal lamps
according to the following signals:
Ignition switch (IG1): ON
Turn-signal lamp switch: ON
The ETACS-ECU flashes the turn-signal lamps
under the following conditions:
Ignition key: "ON" position
Turn-signal lamp switch: Left or right turn-sig-
nal position
.
TECHNICAL DESCRIPTION (COMMENT)
If the turn-signal lamps do not flash normally, the
input circuits from the switches described in "CIR-
CUIT OPERATION" or the ETACS-ECU may be
defective. If the hazard warning lamps do not flash,
the power supply line to the ETACS-ECU (dedicated
to the turn-signal lamps) 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
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 hazard warning lamp.
Q: Do the hazard warning lamps work normally?
YES : Go to Step 7.
NO : Go to Step 2.
SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-355
54B
INTERIOR LAMP
GENERAL DESCRIPTION CONCERNING THE INTERIOR LAMPM1549021800236
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80The following ECUs affect the functions and control
of the interior lamps.
Interior lamp control function
The ETACS-ECU controls the interior lamps by turn-
ing them on and off in the following way:
When a door is opened with the ignition switch
off, the interior lamps up to a luminance of 100
percent. When a door is closed, the interior lamps
dims at a luminance of 65 percent, and goes off
30 seconds later. However if the ignition switch is
turned ON or if a door is locked while the interior
lamps is dimming, the dome lamp will go off at
that point.
When a door is opened with the ignition switch
ON, the interior lamps up at a luminance of 100
percent. When a door is closed, the interior lamps
go off.
When the ignition key is removed with all doors
closed, the interior lamps up at a luminance of
100 percent, and goes off 30 seconds later. How-
ever if the ignition key is inserted again or if a
door is locked while the interior lamps is lighting,
the interior lamps will go off at that point.
To check keyless entry operations more easily,
the interior lamps is flashed once when the doors
are locked. When the doors are unlocked, the
interior lamps at a luminance of 100 percent, and
go off 15 seconds later.
NOTE: The dimmer function can be customised on
vehicles equipped with a multi center display (middle
grade type). Refer to P.54B-486.
NOTE: The dotted lines indicate that lighting mode
when the ignition switch is turned ON, door is locked,
or any door is opened during the timer illumination
time. FUNCTION CONTROL ECU
Interior lamp control function ETACS-ECU
Interior lamp automatic-shutoff function ETACS-ECU
Ignition key hole illumination lamp function ETACS-ECU
Door ajar indicator ETACS-ECU
Seat belt indicator ETACS-ECU
SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-356
Interior lamp automatic-shutoff function
Illuminated interior lamps such as the front dome
lamp, etc. (all lamps using the dome lamp fuse as the
power supply) will automatically go off in the follow-
ing conditions to prevent the battery from discharging
as a result of forgetting to turn off the lamps or
incomplete closing of the door.
When the ignition switch is turned off and more
than 30 minutes pass with the interior lamp illumi-
nated, the interior lamps will go off automatically.
When the ignition switch is turned off and one of
the door switches remains open for 30 minutes
continuously, the interior lamps will go off auto-
matically.
NOTE: The interior lamp automatic shutoff function
can be customised on vehicles equipped with a multi
center display (middle grade type). Refer to
P.54B-486.
Ignition key hole illumination lamp function
The ignition key hole illumination lamp illuminates when the
driver's door is opened with the ignition switch off, and for 30
seconds after the driver's door is closed. It also illuminates for
30 seconds after the ignition key is pulled out. In any case, it
goes out when the ignition switch is turned on.
Door ajar indicator
The combination meter receives the signal sent from the
ETACS-ECU about whether each door is open or closed and
turns the door ajar indicator on and off. While the door ajar indi-
cator is illuminated, the door ajar warning function is activated
and the door ajar indicator flashes 4 times. If the door remains
open even after the 4 warning flashes, the door ajar indicator
will be illuminated again. And when the interior lamp auto-
matic-shutoff function is activated, the door ajar indicator is
extinguished.
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