Page 417 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-417
STEP 6. Check the wiring harness between front door
switch (RH) connector D-34 (terminal 1) and ETACS-ECU
connector C-219 (terminal 10).
NOTE: Also check junction block connector C-204 for loose,
corroded, or damaged terminals, or terminals pushed back in
the connector. If junction block connector C-204 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 front door switch (RH)
connector D-34 (terminal 1) and ETACS-ECU connector
C-219 (terminal 10) in good condition?
YES : Replace the ETACS-ECU. If the functions described
in "CIRCUIT OPERATION" work normally, the input
signal from the front door switch (RH) should be
normal.
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. If the
functions described in "CIRCUIT OPERATION" work
normally, the input signal from the front door switch
(RH) should be normal.
Page 418 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-418
STEP 7. Check front door switch (LH) connector D-22 for
loose, corroded or damaged terminals, or terminals
pushed back in the connector.
Q: Is front door switch (LH) connector D-22 in good
condition?
YES : Go to Step 8.
NO : Repair or replace the damaged component(s). Refer
to GROUP 00E, Harness Connector Inspection
P.00E-2. If the functions described in "CIRCUIT
OPERATION" work normally, the input signal from the
front door switch (LH) should be normal.
STEP 8. Check the front door switch (RH).
Remove the front door switch (LH). Refer to GROUP 42, Door,
Door Assembly P.42-37. Then check continuity between the
switch terminals and the body ground.
Q: Is the front door switch (LH) in good condition?
YES : Go to Step 9.
NO : Replace the front door switch (LH). If the functions
described in "CIRCUIT OPERATION" work normally,
the input signal from the front door switch (LH) should
be normal.
STEP 9. Measure resistance at the lower metal part of the
front door switch (LH) in order to check the ground circuit
to the front door switch (LH).
NOTE: Check that the front door switch (LH) is grounded to the
vehicle body via its mounting screw.
Remove the cap, and measure the resistance value between
the lower metal part and ground.
The resistance should be 2 ohms or less.
Q: Is the measured resistance 2 ohms or less?
YES : Go to Step 10.
NO : Check the installation of the switch, and repair if
necessary. If the functions described in "CIRCUIT
OPERATION" work normally, the input signal from the
front door switch (LH) should be normal.
SWITCH
POSITIONTESTER
CONNECTIONSPECIFIED
CONDITION
Released (ON) 1
body ground Less than 2 ohms
Pressed (OFF) 1
body ground Open circuit
Page 419 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-419
STEP 10. Check ETACS-ECU connector C-218 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is ETACS-ECU connector C-218 in good condition?
YES : Go to Step 11.
NO : Repair or replace the damaged component(s). Refer
to GROUP 00E, Harness Connector Inspection
P.00E-2. If the functions described in "CIRCUIT
OPERATION" work normally, the input signal from the
front door switch (LH) should be normal.
STEP 11. Check the wiring harness between front door
switch (LH) connector D-22 (terminal 1) and ETACS-ECU
connector C-218 (terminal 59).
Q: Is the wiring harness between front door switch (LH)
connector D-22 (terminal 1) and ETACS-ECU connector
C-218 (terminal 59) in good condition?
YES : Replace the ETACS-ECU. If the functions described
in "CIRCUIT OPERATION" work normally, the input
signal from the front door switch (LH) should be
normal.
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. If the
functions described in "CIRCUIT OPERATION" work
normally, the input signal from the front door switch
(LH) should be normal.
Page 420 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-420
INSPECTION PROCEDURE M-5: Column Switch: ETACS-ECU does not receive any signal from the
taillamp switch, the headlamp switch, the passing lamp switch, the dimmer switch or the turn-signal
lamp 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."
.
CIRCUIT OPERATION
The ETACS-ECU operates the following equipment
or functions according to signal from the column
switch (turn-signal lamp and lighting switch):
Light reminder tone alarm function
Turn-signal lamp buzzer
Headlamp
Turn-signal lamp
High-beam indicator
Turn-signal indicators
.
TECHNICAL DESCRIPTION (COMMENT)
If the signal is not normal, the equipment or functions
described in "CIRCUIT OPERATION" do not work
normally. If the signal is not normal, the column
switch (turn-signal lamp and lighting switch) or the
ETACS-ECU may be defective.
.
TROUBLESHOOTING HINTS
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
The column switch (turn-signal lamp and lighting
switch) may be defective
The ETACS-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
Page 421 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-421
STEP 1. Use diagnostic tool MB991958 to select "ECU
COMM Check" on the SWS monitor display.
Check the column-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 "ON" position.
(3) Operate the diagnostic tool 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 (MUT-III) should show "OK" on the "ECU
COMM Check" menu for the "COLUMN ECU" menu.
Q: Is "OK" displayed for the "COLUMN ECU" menu?
YES : Go to Step 2.
NO : Refer to Inspection Procedure A-2 "Communication
with the column switch (column-ECU) is not possible
P.54B-68."
Page 422 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-422
STEP 2. Check the turn-signal lamp and lighting switch.
Remove the turn-signal lamp and the lighting switch. Then
check continuity between the switch terminals.
Q: Are the turn-signal lamp and lighting switch in good
condition?
YES : Go to Step 3.
NO : Replace the turn-signal lamp and the lighting switch.
The input signal from the column switch (turn-signal
lamp and lighting switch) should be able to be
checked and the functions described in the "CIRCUIT
OPERATION" should work normally.
STEP 3. Replace the column switch.
(1) Replace the column switch.
(2) The input signal from the column switch (turn-signal lamp
and lighting switch) should be able to be checked and the
functions described in the "CIRCUIT OPERATION" should
work normally.
Q: Is the input signal from the column switch (turn-signal
lamp and lighting switch) input normal?
YES : No action is necessary and testing is complete.
NO : Replace the ETACS-ECU. The input signal from the
column switch (turn-signal lamp and lighting switch)
should be able to be checked and the functions
described in the "CIRCUIT OPERATION" should work
normally. SWITCH
POSITIONTESTER
CONNECTIONSPECIFIED
CONDITION
OFF 1
2, 2 3, 2 11,
2
12, 5 9, 7 9Open circuit
Taillight switch 5
9 Less than 2 ohms
Headlamp switch5
9, 7 9 Less than 2 ohms
Passing switch 2
12 Less than 2 ohms
Dimmer switch 2
11, 2 12 Less than 2 ohms
Turn-signal lamp
switch (LH)1
2 Less than 2 ohms
Turn-signal lamp
switch (RH)2
3 Less than 2 ohms
Page 423 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-423
INSPECTION PROCEDURE M-6: Column switch: ETACS-ECU does not receive any signal from the
windshield mist wiper switch, the windshield intermittent wiper switch, the windshield low-speed
wiper switch, the windshield high-speed wiper switch or the windshield washer 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."
.
CIRCUIT OPERATION
The ETACS-ECU operates the windshield wiper and
washer according to signal from the windshield wiper
and washer switch.
.
TECHNICAL DESCRIPTION (COMMENT)
If the signal is not normal, the windshield wiper and
washer do not work normally.
.
TROUBLESHOOTING HINTS
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
The column switch may be defective (windshield
wiper and washer switch)
The ETACS-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
Page 424 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-424
STEP 1. Use diagnostic tool MB991958 to select "ECU
COMM Check" on the SWS monitor display.
Check the column-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 "ON" position.
(3) Operate the diagnostic tool 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 (MUT-III) should show "OK" on the "ECU
COMM Check" menu for the "COLUMN ECU" menu.
Q: Is "OK" displayed for the "COLUMN ECU" menu?
YES : Go to Step 2.
NO : Refer to Inspection Procedure A-2 "Communication
with the column switch (column-ECU) is not possible
P.54B-68."