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SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-217
STEP 11. Check overhead console assembly connector
D-03 for loose, corroded or damaged terminals, or
terminals pushed back in the connector.
Q: Is overhead console assembly connector D-03 in good
condition?
YES : Go to Step 12.
NO : Repair or replace the damaged component(s). Refer
to GROUP 00E, Harness Connector Inspection
P.00E-2. Check that the sunroof works normally.
STEP 12. Check the wiring harness between sunroof
switch connector D-03-1 (terminal 4) and overhead
console assembly connector D-03 (terminal 6).
Q: Is the wiring harness between sunroof switch connector
D-03-1 (terminal 4) and overhead console assembly
connector D-03 (terminal 6) in good condition?
YES : Go to Step 13.
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. Check that
the sunroof works normally.
STEP 13. Check the wiring harness between overhead
console assembly connector D-03 (terminal 6) and ground.
Q: Is the wiring harness between overhead console
assembly connector D-03 (terminal 6) and ground in
good condition?
YES : No action is necessary and testing is complete.
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. Check that
the sunroof works normally.
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SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-218
STEP 14. Check the wiring harness between sunroof
switch connector D-03-1 (terminals 3, 5 and 6) and
overhead console assembly connector D-03 (terminals 7, 5
and 4).
Q: Is the wiring harness between sunroof switch connector
D-03-1 (terminals 3, 5 and 6) and overhead console
assembly connector D-03 (terminals 7, 5 and 4) in good
condition?
YES : Go to Step 15.
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. Check that
the sunroof works normally.
STEP 15. Check the wiring harness between sunroof motor
assembly connector D-04 (terminals 6, 7 and 8) and
overhead console assembly connector D-03 (terminals 4, 7
and 5).
Q: Is the wiring harness between sunroof motor assembly
connector D-04 (terminals 6, 7 and 8) and overhead
console assembly connector D-03 (terminals 4, 7 and 5)
in good condition?
YES : Go to Step 16.
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. Check that
the sunroof works normally.
STEP 16. Replace the sunroof switch.
(1) Replace the sunroof switch.
(2) Check that the sunroof works normally.
Q: Does the sunroof works normally?
YES : No action is necessary and testing is complete.
NO : Replace the sunroof motor assembly. Check that the
sunroof works normally.
Page 219 of 1500

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-219
INSPECTION PROCEDURE F-2: Sunroof: Any of the sunroof switch positions is defective.
.
TECHNICAL DESCRIPTION (COMMENT)
The sunroof switch or the sunroof motor assembly
may be defective.
.
TROUBLESHOOTING HINTS
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
The sunroof switch may be defective
The sunroof motor assembly 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
Check the input signal (by using the pulse check mode of
the monitor).
Check the input signals from the sunroof 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 the 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) When each function of the sunroof switch is operated
(turned on), check that diagnostic tool MB991958 sounds.
Q: Does diagnostic tool MB991958 sound when the
sunroof switch is operated?
YES : Replace the sunroof motor assembly. Check that the
sunroof works at all positions normally.
NO : Refer to Inspection Procedure M-8 "ETACS-ECU
does not receive any signal from the up, open or
close/down switch P.54B-429."
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SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-220
INSPECTION PROCEDURE F-3: Sunroof: Sunroof Timer Function does not Work Normally.
NOTE: This troubleshooting requires use of
diagnostic tool MB991958 and SWS monitor kit
MB991813. For details of how to use the SWS moni-
tor, refer to "How to connect SWS monitor
P.54B-13."
.
CIRCUIT OPERATION
The sunroof timer function works according to the
signals from the following switches:
Ignition switch (IG1): OFF
Front door switch: OFF
Vehicle condition
Ignition switch: LOCK position
Front door: Closed
When the driver’s door is opened and closed
while the sunroof timer function is on, the sunroof
operative duration will be changed.
.
TECHNICAL DESCRIPTION (COMMENT)
Is the sunroof timer function does not work normally,
the input circuits from the switches described in
"CIRCUIT OPERATION", the sunroof motor assem-
bly, the ETACS-ECU or the SWS communication line
may be defective.
.
TROUBLESHOOTING HINTS
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
The front door switch may be defective
The sunroof motor assembly 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: Test 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
Page 221 of 1500

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-221
STEP 1. Use diagnostic tool MB991958 to select "ECU
COMM Check" on the SWS monitor display.
Check the following ECUs:
ETACS-ECU
Sunroof-ECU
To prevent damage to diagnostic tool MB991958, always
turn the ignition switch to the "LOCK" (OFF) position
before connecting or disconnecting diagnostic tool
MB991958. Connect special tool MB991910 before con-
necting special tool MB991812. Be sure to connect special
tool MB991806 after turning on special tool MB991824.
(1) Connect the special tool. Refer to "How to connect SWS
monitor P.54B-13."
(2) Turn the ignition switch to the "LOCK" (OFF) position.
(3) Operate the diagnostic tool MB991958 according to the
procedure below to display "ECU COMM Check."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "ECU COMM Check."
(4) diagnostic tool MB991958 should show "OK" on the "ECU
COMM Check" menus for both the "ETACS ECU" and the
"SUNROOF ECU" menus.
Q: Is "OK" displayed for both the "ETACS ECU" and
"SUNROOF ECU" menus?
"OK" is displayed for all the items : Go to Step 2.
"NG" is displayed for the "ETACS ECU" menu : Refer to
Inspection Procedure A-3 "Communication with the
ETACS-ECU is not possible P.54B-74."
"NG" is displayed for the "SUNROOF ECU" menu :
Refer to Inspection Procedure A-5 "Communication
with the sunroof-ECU is not possible P.54B-87."
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SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-222
STEP 2. Check the input signal by using "FUNCTION
DIAG." menu of the SWS monitor.
Observe how the input signal is changed when the ignition
switch is turned from the ON position to the "LOCK" (OFF)
position.
(1) Operate the MUT-III according to the procedure below to
display "SUNROOF-OPE."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "Function Diag."
f. Select "SUNROOF."
g. Select "SUNROOF-OPE."
(2) Check that normal conditions are displayed for the items
described in the table below.
Q: Does the MUT-III display the items "IG SW (IG1)" and
"S/R ECU ACK" as normal condition?
Normal conditions displayed for all the items : Replace
the sunroof motor assembly. Check that the sunroof
timer function works normally.
Normal condition is not displayed for the "IG SW (IG1)" :
Refer to Inspection Procedure M-2 "ETACS-ECU
does not receive a signal from the ignition switch
(IG1) P.54B-408."
Normal condition is not displayed for the "S/R ECU
ACK" : Replace the sunroof motor assembly. Check that the
sunroof timer function works normally. ITEM NO. ITEM NAME NORMAL
CONDITION
ITEM 30 IG SW (IG1) OFF
ITEM 72 S/R ECU ACK NORMAL ACK
Page 223 of 1500

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-223
54B
WINDSHIELD WIPER AND WASHER
GENERAL DESCRIPTION CONCERNING THE WINDSHIELD WIPER AND WASHERM1549021500257
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80The following ECUs affect the functions and control
of the windshield wiper and washer.
Windshield wiper and washer control function
.
Intermittent control (vehicle speed-dependent
variable type)
ETACS-ECU uses the dial position of the variable intermittent
wiper control switch and the vehicle speed signal sent by the
combination meter to calculate the interval to be sent to the
front-ECU.
NOTE: The speed-sensitive wiper can be customized on vehi-
cles equipped with a multi center display (middle grade type).
Refer to P.54B-486.
The front-ECU determines the intermittent time T1 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, then turns OFF the wind-
shield wiper drive signal. After the intermittent time T1 seconds
from when the windshield wiper drive signal turned ON, the
windshield wiper drive signal is turned ON again and the above
operation is repeated.
NOTE: If the intermittent time T1 is within 2 seconds, the wiper
is operated consecutively at LOW-speed by the front-ECU.
.
FUNCTION CONTROL ECU
Windshield wiper and washer
control functionIntermittent control (Vehicle
speed-dependent variable type)ETACS-ECU, front-ECU, column
switch
Mist wiper control ETACS-ECU, column switch
Low speed wiper and high speed
wiper controlETACS-ECU, column switch
Washer control ETACS-ECU, column switch
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SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-224
Mist wiper control
When the ignition switch is in the ACC or ON posi-
tion, and the windshield mist wiper 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 wind-
shield 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 predeter-
mined 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 T1 seconds
after the last windshield wiper auto-stop signal turn-
ing ON.
.
Low speed wiper and high speed wiper control
When the ignition switch is at the ACC or ON posi-
tion, and the windshield low speed wiper switch of
the column switch is turned ON, the front-ECU turns
ON the windshield wiper drive signal, turns OFF (LO)
the windshield wiper speed relay, and operates the windshield wiper at low speed. Next, when the wind-
shield high speed wiper switch is turned ON, the
windshield wiper drive signal is turned ON, the wind-
shield wiper speed switching relay is turned ON (HI),
and the windshield wiper is operated at high speed.
.