Page 241 of 1500
SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-241
TECHNICAL DESCRIPTION (COMMENT)
If the windshield wipers do not stop at predetermined
park position, the windshield wiper motor or the
front-ECU may be defective.
.
TROUBLESHOOTING HINTS
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
The wiring harness or connectors may have
loose, corroded, or damaged terminals, or termi-
nals pushed back in the connector
The windshield wiper motor may be defective
The front-ECU may be defective
DIAGNOSIS
Required Special Tool:
MB991223: Harness Set
STEP1. Check windshield wiper motor connector A-03 for
loose, corroded or damaged terminals, or terminals
pushed back in the connector.
Q: Is windshield wiper motor connector A-03 in good
condition?
YES : Go to Step 2.
NO : Repair or replace the damaged component(s). Refer
to GROUP 00E, Harness Connector Inspection
P.00E-2. Verify that the windshield wiper works
normally.
Page 242 of 1500
SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-242
STEP 2. Check the windshield wiper motor.
(1) Disconnect windshield wiper motor connector A-03.
(2) Connect the vehicle battery to the windshield wiper motor
connector as shown, and operate the windshield wiper at
low speed. While the windshield wiper is working,
disconnect the battery at positions other than the
predetermined park position to stop the windshield wiper
motor.
(3) When the battery is connected as shown, the motor should
run at low speed, and then stop at the predetermined park
position.
Q: Does the windshield wiper motor operate normally?
YES : Go to Step 3.
NO : Replace the windshield wiper motor. The windshield
wiper should now stop at the predetermined park
position.
Page 243 of 1500
SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-243
STEP 3. Check the ignition switch (ACC) circuit to the
windshield wiper motor. Measure the voltage at windshield
wiper motor connector A-03.
(1) Disconnect windshield wiper motor connector A-03 and
measure the voltage available at the wiring harness side of
the connector.
(2) Turn the ignition switch to the "ACC" position.
(3) Measure the voltage between terminal 3 and ground.
The voltage should measure approximately 12 volts
(battery positive voltage).
Q: Is the measured voltage approximately 12 volts (battery
positive voltage)?
YES : Go to Step 5.
NO : Go to Step 4.
STEP 4. Check the wiring harness between windshield
wiper motor connector A-03 (terminal 3) and the ignition
switch (ACC).
Page 244 of 1500

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-244
NOTE: Also check intermediate connector C-29 for loose, cor-
roded, or damaged terminals, or terminals pushed back in the
connector. If intermediate connector C-29 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 windshield wiper motor
connector A-03 (terminal 3) and the ignition switch
(ACC) 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. Verify that
the windshield wiper works normally.
STEP 5. Check front-ECU connector A-12X for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is front-ECU connector A-12X in good condition?
YES : Go to Step 6.
NO : Repair or replace the damaged component(s). Refer
to GROUP 00E, Harness Connector Inspection
P.00E-2. The windshield wiper should stop at the
predetermined park position.
Page 245 of 1500
SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-245
STEP 6. Check the wiring harness between windshield
wiper motor connector A-03 (terminal 2) and front-ECU
connector A-12X (terminal 29).
Q: Is the wiring harness between windshield wiper motor
connector A-03 (terminal 2) and front-ECU connector
A-12X (terminal 29) in good condition?
YES : Replace the front-ECU. The windshield wiper should
stop at the predetermined park position.
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. Verify that
the windshield wiper works normally
Page 246 of 1500

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-246
INSPECTION PROCEDURE G-5: Windshield Wiper and Washer: The windshield intermittent wiper
interval cannot be adjusted by using the variable intermittent wiper control switch.
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."
.
TECHNICAL DESCRIPTION (COMMENT)
If the windshield intermittent wiper interval is not
changed by operating the windshield intermittent
wiper interval adjusting knob or according to the
vehicle speed, the column switch, the ETACS-ECU
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 ETACS-ECU may be defective
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
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SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-247
Check the input signal by using "DATA LIST" menu of the
SWS monitor.
Set each switch to the following condition to check input signals
from the variable intermittent wiper control switch:
Ignition switch: ACC
Windshield wiper switch: INT
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) Operate Diagnostic Tool MB991958 according to the
procedure below to display "F.WIPER INT."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "Function Diag."
f. Select "WIPER."
g . S e l e c t " F. W I P E R I N T. "
(3) Check that normal conditions are displayed for the items
described in the table below.
NOTE: Also check that the windshield wiper interval
changes smoothly when the variable intermittent wiper con-
trol switch is rotated from "SLOW" to "FAST" position.
Q: Does the value change within the normal range when
the windshield intermittent wiper interval adjusting
knob is rotated?
YES : Replace the front-ECU. Check that the windshield
intermittent wiper interval changes according to the
vehicle speed or while the windshield intermittent
wiper interval adjusting knob is rotated.
NO : Refer to Inspection Procedure M-7 "ETACS-ECU
does not receive any signal from the variable
intermittent wiper control switch P.54B-426." ITEM NO. ITEM NAME NORMAL
CONDITION
ITEM 37 INT WIPER TIME 1.6
19.0 s
Page 248 of 1500

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-248
INSPECTION PROCEDURE G-6: Windshield Wiper and Washer: The windshield intermittent wiper
interval is not changed according to the vehicle speed.
NOTE: This troubleshooting procedure requires use
of Diagnostic Tool MB991958 and SWS monitor kit
MB991813. For details on how to use the SWS mon-
itor, refer to "How to connect SWS monitor
P.54B-13."
.
TECHNICAL DESCRIPTION (COMMENT)
If the windshield intermittent wiper interval does not
change according to the vehicle speed, the
ETACS-ECU or the front-ECU may be defective.
.
TROUBLESHOOTING HINTS
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
The wiring harness or connectors may have
loose, corroded, or damaged terminals, or termi-
nals pushed back in the connector
The combination meter may be defective
The ETACS-ECU may be defective
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