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SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-192
STEP 2. Check the input signal (by using the pulse check
mode of the monitor).
Check input signals from the transmitter.
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 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) Push the transmitter "LOCK" or "UNLOCK" button.
(4) Check that diagnostic tool MB991958 sounds
Q: When the transmitter "LOCK" or "UNLOCK" button is
turned ON, does diagnostic tool MB991958 sound?
YES : Replace the ETACS-ECU. All the doors can be locked
or unlocked by means of the transmitter.
NO : Refer to Inspection Procedure N-8 "ETACS-ECU
does not receive any signal from the lock, unlock,
trunk or panic switch P.54B-472."
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SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-193
INSPECTION PROCEDURE E-2: Keyless Entry System: The dome lamp, the turn-signal lamps and the
horn do not operate through the answerback function.
.
CIRCUIT OPERATION
The ETACS-ECU operates the following functions
when it receives lock or unlock signal from the trans-
mitter:
Dome lamp answerback function
Turn-signal lamp answerback function
Horn answerback function
.
TECHNICAL DESCRIPTION (COMMENT)
The turn-signal lamps and horn answerback func-
tions can be disabled or enabled. However, the dome
lamp answerback function cannot be disabled.
.
TROUBLESHOOTING HINTS
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
The turn-signal lamp may be defective
The dome lamp may be defective
The horn may be defective
The ETACS-ECU may be defective
The wiring harness or connectors may have
loose, corroded, or damaged terminals, or termi-
nals pushed back in the connector
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SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-203
STEP 2. Check the input signal (by using the pulse check
mode of the monitor).
Check the input signals from the following switches:
Key reminder switch
Hazard warning lamp 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 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) Check the switches (see table below) applicable for the
input signal check are operated.
(4) Check diagnostic tool MB991958 sounds or not.
Q: When the key reminder switch and the hazard warning
lamp switch are operated, does diagnostic tool
MB991958 sound in each case?
Buzzer of diagnostic tool MB991958 sounds normally. :
Replace the ETACS-ECU. Verify that the encrypted
code can be registered in the transmitter.
diagnostic tool MB991958 does not sound when the
ignition key is removed and reinserted : Refer to
Inspection Procedure N-1 "ETACS-ECU does not
receive any signal from the key reminder switch
P.54B-432."
diagnostic tool MB991958 does not sound when the
hazard warning lamp switch is turned from "OFF" to
"ON" : Refer to Inspection Procedure N-2 "ETACS-ECU
does not receive any signal from the hazard warning
lamp switch P.54B-436." ITEM NAME CHECK CONDITION
Key reminder switch Remove and reinsert the
ignition key
Hazard warning lamp switch Turn the hazard warning lamp
switch from "OFF" to "ON"
position.
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SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-205
INSPECTION PROCEDURE E-4: Keyless Entry System: The trunk is not opened when the keyless
entry transmitter "TRUNK" button is operated.
.
CIRCUIT OPERATION
A receiver is incorporated in the ETACS-ECU. This
receiver receives a lock or unlock signal from the
transmitter.
.
TROUBLESHOOTING HINTS
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
The RKE transmitter may be defective
The ETACS-ECU 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
STEP 1. Check that the doors can be locked and unlocked
by using the keyless entry transmitter.
Q: Can the doors be locked and unlocked normally when
the keyless entry transmitter is operated?
YES : Go to Step 2.
NO : Refer to Inspection Procedure E-1 "Keyless entry
system does not operate P.54B-191."
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SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-206
STEP 2. Check the input signal (by using the pulse check
mode of the monitor).
Check input signals from the transmitter.
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 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) Push the transmitter "TRUNK" button.
(4) Check that diagnostic tool MB991958 sounds
Q: When the transmitter "TRUNK" button is turned ON,
does diagnostic tool MB991958 sound?
YES : Go to Step 3.
NO : Refer to Inspection Procedure N-8 "ETACS-ECU
does not receive any signal from the lock, unlock,
trunk or panic switch P.54B-472."
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SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-208
STEP 5. Check the wiring harness between trunk lid latch
assembly connector F-05 (terminal 1) and ETACS-ECU
connector C-217.
NOTE: Also check intermediate connector C-28 for loose, cor-
roded, or damaged terminals, or terminals pushed back in the
connector. If intermediate connector C-28 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 trunk lid latch assembly
connector F-05 (terminal 1) and ETACS-ECU connector
C-217 in good condition?
YES : Replace the ETACS-ECU. All the doors can be locked
or unlocked by means of the transmitter.
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.
Page 212 of 1500
SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-212
STEP 3. Check the wiring harness between sunroof motor
assembly connector D-04 (terminal 1) and fusible link (5).
NOTE: Also check junction block connectors C-212, C-215 and
intermediate connector C-27 for loose, corroded, or damaged
terminals, or terminals pushed back in the connector. If junction
block connector C-212, C-215 or 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 1) and fusible link (5) 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-214
NOTE: Also check junction block connectors C-215 and C-205
for loose, corroded, or damaged terminals, or terminals pushed
back in the connector. If junction block connector C-215 or
C-205 is damaged, repair or replace the damaged compo-
nent(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 2) and the ignition switch (IG2)
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.
STEP 6. Check the ground circuit to the sunroof motor
assembly. Measure the resistance at sunroof motor
assembly connector D-04.
(1) Disconnect sunroof motor assembly connector D-04 and
measure the resistance available at the wiring harness side
of the connector.
(2) Measure the resistance value between terminal 5 and
ground.
The resistance should be 2 ohms or less.
Q: Is the measured resistance 2 ohms or less?
YES : Go to Step 8.
NO : Go to Step 7.