SWS DIAGNOSIS
SIMPLIFIED WIRING SYSTEM (SWS)54B-22
NOTE: When checking the input signals (off, tail,
low-beam or high-beam), turn the ignition switch to
the "ON" position in order to disable the headlamp
automatic shutoff function. However, since the
headlamp operation does not depend on the ignition
switch positions, the diagnostic tool MB991958
(MUT-III Sub Assembly) does not display the title "IGNITION SWITCH". HEADLAMP
LO00 Headlight switch
HEADLAMP SW (COLUMN
ECU)ON
03 Passing lamp
switchPASSING SW (COLUMN
ECU)OFF
30 Ignition switch
(IG1)IG SW (IG1) (ETACS ECU) ON or OFF
35 Headlight
automatic shutoff
functionH/L AUTO-CUT (ETACS
ECU)OFF
70 Response by the
front-ECUFRONT ECU ACK (FRONT
ECU)NORMAL ACK
PASSING
LAMP03 Passing lamp
switchPASSING SW (COLUMN
ECU)ON
70 Response by the
front-ECUFRONT ECU ACK (FRONT
ECU)NORMAL ACK or HI-BEAM
ACK
F.FOG LAMP 00 Headlight switch
HEADLAMP SW (COLUMN
ECU)ON
36 Front fog lamp
switchF.FOG LAMP (COLUMN
ECU)ON
35 Headlight
automatic shutoff
functionH/L AUTO-CUT (ETACS
ECU)OFF
30 Ignition switch
(IG1)IG SW (IG1) (ETACS ECU) ON or OFF
70 Response by the
front-ECUFRONT ECU ACK (FRONT
ECU)NORMAL ACK or HI-BEAM
ACK
TAIL LAMP 00 Headlight switch
HEADLAMP SW (COLUMN
ECU)OFF
01 Tail lamp switch TAILLAMP SW (COLUMN
ECU)ON
03 Passing lamp
switchPASSING SW (COLUMN
ECU)OFF
30 Ignition switch
(IG1)IG SW (IG1) (ETACS ECU) ON or OFF
35 Headlight
automatic shutoff
functionH/L AUTO-CUT (ETACS
ECU)OFF
70 Response by the
front-ECUFRONT ECU ACK (FRONT
ECU)NORMAL ACK ITEM ITEM NO. INPUT SIGNAL DISPLAY ON
DIAGNOSTIC TOOLNORMAL CONDITION
SWS DIAGNOSIS
SIMPLIFIED WIRING SYSTEM (SWS)54B-23
For checking item "HEADLAMP HI", the diagnostic
tool MB991958 (MUT-III Sub Assembly) displays
"OFF" on the item No.2 "DIMMER SW" when the
headlamps are at high-beam. Therefore, the
diagnostic tool MB991958 (MUT-III Sub Assembly)
should display "ON" momentarily when the dimmer
switch is operated.
.
TURN SIGNAL
.
BUZZER
NOTE: The headlamp automatic shutoff function
operates approximately one second after the lighting
monitor tone alarm starts sounding, and then the
tone alarm ceases sounding.
.
ITEM ITEM NO. INPUT SIGNAL DISPLAY ON
DIAGNOSTIC TOOLNORMAL CONDITION
TURN-SIG.LH 10 Turn-signal lamp
switch (RH)T/S RH SW (COLUMN
ECU)OFF
11 Tu r n - s i g n a l l a m p
switch (LH)T/S LH SW (COLUMN
ECU)ON
30 Ignition switch
(IG1)IG SW (IG1) (ETACS ECU) ON
TURN-SIG.RH 10 Turn-signal lamp
switch (RH)T/S RH SW (COLUMN
ECU)ON
11 Tu r n - s i g n a l l a m p
switch (LH)T/S LH SW (COLUMN
ECU)OFF
30 Ignition switch
(IG1)IG SW (IG1) (ETACS ECU) ON
ITEM ITEM NO. INPUT SIGNAL DISPLAY ON DIAGNOSTIC
TOOLNORMAL CONDITION
LGT
MONI.ALRM00 Headlamp switch
HEADLAMP SW (COLUMN
ECU)Either is ON
01 Tail lamp switch TAILLAMP SW (COLUMN
ECU)
30 Ignition switch
(IG1)IG SW (IG1) (ETACS ECU) OFF
32 Front door switch FRONT DOOR SW (ETACS
ECU)ON
35 Headlamp
automatic shutoff
functionH/L AUTO-CUT (ETACS
ECU)OFF
43 Tone alarm BUZZER (ETACS ECU) ON
OTHER
ALARM30 Ignition switch
(IG1)IG SW (IG1) (ETACS ECU) ON
43 Tone alarm BUZZER (ETACS ECU) ON
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
INPUT SIGNAL CHART
SIMPLIFIED WIRING SYSTEM (SWS)54B-61
INPUT SIGNAL CHARTM1549024200501
SWS MONITOR
If a problem is found in the Data List inspection,
observe the table below.
SYMPTOM INSPECTION
PROCEDUREREFERENCE
PA G E
ETACS-ECU does not receive any signal from the ignition switch (ACC). M-1
P.54B-405
ETACS-ECU does not receive any signal from the ignition switch (IG1). M-2
P.54B-408
ETACS-ECU does not receive any signal from the fog lamp switch.M-3
P.54B-410
ETACS-ECU does not receive any signal from the front door switches. M-4
P.54B-413
Column switch ETACS-ECU does not receive any signal from the tail
lamp switch.M-5
P.54B-420
ETACS-ECU does not receive any signal from the
headlamp switch.
ETACS-ECU does not receive any signal from the
passing lamp switch.
ETACS-ECU does not receive any signal from the
dimmer switch.
ETACS-ECU does not receive any signal from the
turn-signal lamp switch.
ETACS-ECU does not receive any signal from the
windshield mist wiper switch.M-6
P.54B-423
ETACS-ECU does not receive any signal from the
windshield intermittent wiper switch.
ETACS-ECU does not receive any signal from the
windshield low-speed wiper switch.
ETACS-ECU does not receive any signal from the
windshield high-speed wiper switch.
ETACS-ECU does not receive any signal from the
variable intermittent wiper control switch.M-7
P.54B-426
ETACS-ECU does not receive any signal from the
windshield washer switch.M-6
P.54B-423
Sunroof switch ETACS-ECU does not receive any signal from the up,
open or close/down switch.M-8
P.54B-429
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-101
Normal condition is not displayed for "FRONT DOOR
SW" : Refer to Inspection Procedure M-4 "ETACS-ECU
does not receive any signal from the front door
switches P.54B-413."
Normal condition is not displayed for "H/L AUTO-CUT" :
Refer to Inspection Procedure H-9 "Headlamp
automatic shutoff function does not work normally
P.54B-305."
Normal condition is not displayed for "BUZZER" :
Replace the ETACS-ECU. The lamp reminder tone
alarm function should now work normally.
INSPECTION PROCEDURE B-3: Tone Alarm: Seat Belt 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 receives the driver's seat belt
switch ON signal from the ignition switch (IG1) and
the combination meter, and then controls the seat
belt tone alarm function.
The ETACS-ECU operates the seat belt tone alarm
function under the following conditions:
Ignition switch: "ON" position
Driver's seat belt: Unfastened
.
TECHNICAL DESCRIPTION (COMMENT)
If the seat belt tone alarm does not work, connec-
tor(s), wiring harness in the CAN bus lines, the com-
bination meter, the ETACS-ECU or the input signal
circuit 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