SWS DIAGNOSIS
SIMPLIFIED WIRING SYSTEM (SWS)54B-15
HOW TO CHECK ECUSM1549014900640
1. Use the diagnostic tool MB991958 (MUT-III Sub
Assembly) and the SWS monitor kit to check
ECUs.
2. The following ECUs can be checked by using the
diagnostic tool MB991958 (MUT-III Sub
Assembly) and the SWS monitor kit.NOTE: The "ECU COMM Check" function checks
the communication status of ECUs. "NG" does not
always mean ECU malfunction. If a malfunction is
found by the "ECU COMM Check", proceed to
"Symptom Procedure" (Refer to P.54B-57).
SWS monitor kit-compatible ECUs and their conditions
NOTE: .
*1: If the ignition switch is turned to "LOCK" (OFF)
or "ACC" when "NG" is displayed beside "ETACS
ECU" or the signal request line is abnormal, the
diagnostic tool shows "NG" beside the "COLUMN
ECU".
*2: When "NG" is displayed beside "ETACS
ECU", the diagnostic tool shows "NG" beside the
"FRONT ECU" and "SUNROOF ECU".
SERVICE DATA CHECKM1549015000714
Use the diagnostic tool MB991958 (MUT-III Sub
Assembly) and the SWS monitor kit to check
"Data List" or "Function Diag.". This "Data List" or
"Function Diag." check is applicable for signals,
which are transmitted and received through the
SWS communication line. For input signals, which
are not compatible with the SWS monitor kit, refer
to the Pulse Check procedure (by using the
diagnostic tool or voltmeter) P.54B-24.1. The following input signals can be checked by
using the diagnostic tool MB991958 (MUT-III Sub
Assembly) and the SWS monitor kit.
NOTE: If a problem is found in the "Service Data"
check, refer to Input Signal Chart P.54B-61.
The table below shows the service data and their
normal condition, which are displayed during the
"Data List."
.
ITEM
No.ECUS TO BE
CHECKEDDISPLAY ON
DIAGNOSTIC
TOOLNORMAL
CONDITI
ONECU CONDITION
80 Column switch
(column-ECU)COLUMN ECU
OK*
1All of the column switch, power supply,
ground and interconnecting
communication lines are normal
83 ETACS-ECU ETACS-ECU OK All of the ETACS-ECU switch, power
supply, ground and interconnecting
communication lines are normal
84 Front-ECU FRONT ECU
OK*
2All of the front-ECU, power supply, ground
and interconnecting communication lines
are normal
86 Sunroof motor
assembly
(sunroof-ECU)SUNROOF ECU
OK*
2All of the sunroof motor assembly, power
supply, ground and interconnecting
communication lines are normal
SWS DIAGNOSIS
SIMPLIFIED WIRING SYSTEM (SWS)54B-16
COLUMN ECU
.
CHECK
ITEMITEM NO. DISPLAY ON
DIAGNOSTIC
TOOLCHECK CONDITION NORMAL
CONDITION
Dimmer
switch02 DIMMER SW Dimmer switch: ON ON
Dimmer switch: OFF OFF
Windshield
washer
switch09 FRONT
WASH.SWWindshield washer switch: ON ON
Windshield washer switch: OFF OFF
Headlamp
switch00
HEADLAMP
SWLighting switch: HEAD ON
Lighting switch: Other than HEAD OFF
Windshield
high-speed
wiper switch07 HI WIPER SW Wiper switch: HI ON
Wiper switch: Other than HI OFF
With or
without
windshield
intermittent
wiper interval
adjusting
knob15 INT WIPE
KNOBVehicles with intermittent wiper control EQUIP
Vehicles without intermittent wiper control NON
Windshield
intermittent
wiper switch05 INT WIPER SW Wiper switch: INT ON
Wiper switch: Other than INT OFF
Windshield
low-speed
wiper switch06 LO WIPER SW Wiper switch: LO ON
Wiper switch: Other than LO OFF
Windshield
mist wiper
switch08 MIST WIPER
SWWiper switch: Mist ON
Wiper switch: Other than "Mist" position OFF
Passing lamp
switch03 PASSING SW Passing lamp switch: ON ON
Passing lamp switch: OFF OFF
Ta i l l a m p
switch01 TAILLAMP SW Lighting switch: TAIL ON
Lighting switch: OFF OFF
Turn-signal
lamp switch
(LH)11 T/S LH SW Turn-signal lamp switch: LH ON
Turn-signal lamp switch: Other than LH OFF
Turn-signal
lamp switch
(RH)10 T/S RH SW Turn-signal lamp switch: RH ON
Turn-signal lamp switch: Other than RH OFF
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
SWS DIAGNOSIS
SIMPLIFIED WIRING SYSTEM (SWS)54B-24
SUNROOF
PULSE CHECK
M1549015100562
1. The input signals (signals other than SWS
communication line signals), which are
compatible with the SWS monitor by using the
diagnostic tool MB991958 (MUT-III Sub
Assembly) or voltmeter, can be confirmed by the
Pulse Check.2. Use the diagnostic tool MB991958 (MUT-III Sub
Assembly) or voltmeter to check the following
input signals.
NOTE: If a problem is found in the Pulse Check,
refer to Input Signal Chart P.54B-61.
Switches and their conditions, which are applicable
for Pulse CheckITEM ITEM NO. INPUT SIGNAL DISPLAY ON
DIAGNOSTIC TOOLNORMAL CONDITION
SUNROOF
OPE.30 Ignition switch
(IG1)IG SW (IG1) (ETACS ECU) ON
72 Response by the
sunroof-ECUS/R ECU ACK (SUNROOF
ECU)INPUT CHECK (only
momentarily when switch is
operated)
INPUT SIGNAL REQUIREMENTS FOR SOUNDING TONE
ALARM
Key reminder switch When the ignition key is pulled out
Hazard warning lamp switch When the switch is turned from off to on
Door switches A door is opened when all the doors are
closed
Door lock key cylinder switch When a door is locked or unlocked by a key
cylinder
Door lock actuators Move the door lock knob from lock position
to unlock position or vice versa
Door lock switch (incorporated in the power window main
switch and front power window sub switch)When a door is locked or unlocked by a door
lock switch
Keyless entry transmitter When the switch is turned from off to on
Interior lamp loaded signal Illuminates the interior lamps
DIAGNOSTIC TROUBLE CODE PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-39
STEP 2. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Replace the ETACS-ECU. After replacement, verify
that the DTC is not reset.
NO : There is an intermittent malfunction such as poor
engaged connector(s) or open circuit (Refer to
GROUP 00, How to Cope with Intermittent
Malfunction P.00-14).
DTC 011 (U1100): Engine ECU Time-out
DTC 012 (U1101): A/T ECU Time-out
If DTC (U1100) or 012 is set in the ETACS-ECU,
always diagnose the CAN main bus line.
Whenever the ECU is replaced, ensure that the
communication circuit is normal.
.
TROUBLE JUDGMENT
DTC 011 (U1100)
The ETACS-ECU receives engine control sys-
tem-related signal from the Engine ECU. If the
ECU cannot receive the signal, DTC 011
(U1100) will be set. DTC 012 (U1101)
The ETACS-ECU receives automatic transaxle
control system-related signal from the A/T ECU.
If automatic transaxle control system-related sig-
nal cannot be received, DTC 012 (U1101) will be
set.
.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
Connector(s) or wiring harness in the CAN bus
lines between the Engine ECU or A/T ECU and
the ETACS-ECU, the power supply system to the
Engine ECU or A/T ECU, the Engine ECU or A/T
ECU itself, or the ETACS-ECU may be defective.
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
DIAGNOSTIC TROUBLE CODE PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-46
STEP 5. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Replace the ETACS-ECU. On completion, verify that
the DTC is not reset.
NO : A poor connection, open circuit or other intermittent
malfunction is present in the CAN bus lines between
the A/C-ECU and the ETACS-ECU (Refer to GROUP
00, How to Cope with Intermittent Malfunction
P.00-14).
DTC 014 (U1108): Combination Meter Time-out.
If DTC (U1108) is set in the ETACS-ECU, always
diagnose the CAN main bus line.
Whenever the ECU is replaced, ensure that the
communication circuit is normal.
.
TROUBLE JUDGMENT
The ETACS-ECU receives combination
meter-related signal from the combination meter. If
the ECU cannot receive the signal, DTC 014
(U1108) will be set.
.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
Connector(s) or wiring harness in the CAN bus
lines between the combination meter and the
ETACS-ECU, the power supply system to the
combination meter, the combination meter itself,
or the ETACS-ECU may be defective.
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
Past trouble
If DTC 014 (U1108) is stored as a past trouble,
carry out diagnosis with particular emphasis on
wiring and connector(s) in the CAN bus line
between the combination meter and the
ETACS-ECU, and the power supply system to the
combination meter. For diagnosis procedures,
refer to "How to cope with past trouble" (Refer to
GROUP 00, How to treat past trouble P.00-16).
NOTE: You cannot find a past trouble, by the
MUT-III CAN bus diagnostics even if there is a
failure in CAN bus lines. In this case, refer to
GROUP 00, How to Cope with Intermittent Mal-
function P.00-14 and check the CAN bus lines.
You can narrow down the possible cause of the
trouble by referring to the DTC, which is set
regarding the CAN communication-linked ECUs
(Refer to GROUP 54C, CAN Bus Line Diagnosis
P.54C-6).
.
DIAGNOSTIC TROUBLE CODE PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-53
STEP 5. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Replace the ETACS-ECU. On completion, verify that
the DTC is not reset.
NO : A poor connection, open circuit or other intermittent
malfunction is present in the CAN bus lines between
the multi center display and the ETACS-ECU (Refer
to GROUP 00, How to Cope with Intermittent
Malfunction P.00-14).
DTC 021 (U1128): Failure Information on Combination Meter.
If DTC 021 (U1128) is set in the ETACS-ECU,
always diagnose the CAN main bus line.
Whenever the ECU is replaced, ensure that the
communication circuit is normal.
The combination meter- related DTC may be set
when DTC 021 (U1128) is set. (For details refer
to GROUP 00, Affiliated DTC Reference Table
P.00-17.) Diagnose the combination meter first
when the combination meter- related DTC is set.
.
TROUBLE JUDGMENT
The ETACS-ECU receives combination
meter-related signal from the combination meter via
the CAN bus lines. If a fail-safe related data is con-
tained in the signal from the combination meter,
DTC 021 (U1128) will be stored.
.
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
The wiring harness wire or connectors may have
loose, corroded, or damage terminals, or termi-
nals pushed back in the connector, the Engine-
ECU, the combination meter or the ETACS-ECU
may be defective.
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80