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-95
Light reminder tone alarm function
When the taillights or headlamps is the ON position, if the igni-
tion key is removed and the driver's door is opened, a tone
alarm will sound continuously to warn that the lamps are on.
However, if the taillights or headlamps have been turned off by
the headlamp automatic-shutoff function, the tone alarm will not
sound.
Seat belt tone alarm function
SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-98
54B
INSPECTION PROCEDURE B-2: Tone Alarm: Light Reminder Tone Alarm 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 light reminder tone
alarm function according to the following signals:
Ignition switch (IG1): OFF
Ignition key reminder switch: ON
Front door switch (RH): ON
Taillamp switch: ON
Headlamp switch: ON
The ETACS-ECU operates the lamp reminder tone
alarm function under the following conditions:
Ignition switch: "LOCK" (OFF) position
Ignition key: Removed from the ignition key cylin-
der
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 or the ETACS-ECU
may be defective (refer to "CIRCUIT OPERATION").
.
TROUBLESHOOTING HINTS
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
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
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
SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-100
STEP 2. Check the input signal by using "FUNCTION
DIAG." menu of the SWS monitor.
Check the input signals from the following switches:
Ignition switch: OFF (key removed)
Lighting switch: TAIL or HEAD
Driver’s door: open
Front passenger's door: closed
(1) Operate diagnostic tool MB991958 according to the
procedure below to display "LGT MONI. ALRM."
a. Select "Interactive Diagnosis."
b. Select "System Select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "Function Diag."
f. Select "BUZZER."
g. Select "LGT MONI. ALRM."
(2) Check that normal conditions are displayed for the items
described in the table below.
NOTE: diagnostic tool MB991958 display changes when
the driver's or the front passenger's door is opened. If any of
the doors is open, the system cannot be checked correctly.
Q: Does diagnostic tool MB991958 display "HEADLAMP
SW", "TAILLAMP SW", "IG SW IG1", "FRONT DOOR
SW", "H/L AUTO-CUT" and "BUZZER" as normal
condition?
Normal conditions are displayed for all the items :
Replace the ETACS-ECU. The lamp reminder tone
alarm function should now work normally.
Normal condition is not displayed for "HEADLIGHT SW"
: Refer to Inspection Procedure M-5 "ETACS-ECU
does not receive any signal from the headlamp switch
P.54B-420."
Normal condition is not displayed for "TAILLIGHT SW" :
Refer to Inspection Procedure M-5 "ETACS-ECU
does not receive any signal from the taillamp switch
P.54B-420."
Normal condition is not displayed for "IG SW (IG1)" :
Refer to Inspection Procedure M-2 "ETACS-ECU
does not receive any signal from the ignition switch
(IG1) P.54B-408." ITEM NO. ITEM NAME NORMAL CONDITION
ITEM 00 HEADLAMP SW Either of items is ON
ITEM 01 TAILLAMP SW
ITEM 30 IG SW IG1 OFF
ITEM 32 FRONT DOOR SW ON
ITEM 35 H/L AUTO-CUT OFF
ITEM 43 BUZZER ON
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-260
INSPECTION PROCEDURE H-1: Headlamp and Taillamp: The taillamps do not illuminate normally.
NOTE: This troubleshooting procedure requires the
use of Diagnostic Tool MB991958 and SWS monitor
kit MB991813. For details on how to connect the
SWS monitor, refer to "How to connect SWS monitor
P.54B-13."
.
CIRCUIT OPERATION
When the lighting switch is set to "TAIL" position, the
"TAIL" signal is sent through the column-ECU (incor-
porated in the column switch) to the front-ECU. If the
front-ECU receives the "TAIL" signal through the col-
umn-ECU, the front-ECU turns on the taillamp relay
(incorporated in the front-ECU), thus causing the
taillamps to illuminate.
.
TECHNICAL DESCRIPTION (COMMENT)
If the taillamps do not illuminate normally, the column
switch or the front-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 front-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