Page 433 of 1500
INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-433
STEP 2. Check the key reminder switch.
Disconnect key reminder switch connector C-310. Then check
continuity between terminals.
Q: Is the key reminder switch in good condition?
YES : Go to Step 3.
NO : Replace the key reminder switch. If the functions
described in "CIRCUIT OPERATION" work normally,
the input signal from the key reminder switch should
be normal.
STEP 3. Check the ground circuit to the key reminder
switch. Measure the resistance at key reminder switch
connector C-310.
(1) Disconnect key reminder switch connector C-310 and
measure the resistance available at the wiring harness side
of the connector.
(2) Measure the resistance value between terminal 4 and
ground.
The resistance should be 2 ohms or less.
Q: Is the measured resistance 2 ohms or less?
YES : Go to Step 5.
NO : Go to Step 4. IGNITION KEY TESTER
CONNECTIONSPECIFIED
CONDITION
Removed 4
6 Open circuit
Inserted 4
6 Less than 2 ohms
Page 434 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-434
STEP 4. Check the wiring harness between key reminder
switch connector C-310 (terminal 4) and ground.
Q: Is the wiring harness between key reminder switch
connector C-310 (terminal 4) 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. If the
functions described in "CIRCUIT OPERATION" work
normally, the input signal from the key reminder
switch should be normal.
STEP 5. Check ETACS-ECU connector C-217 for loose,
corroded or damaged terminals, or terminals pushed back
in the connector.
Q: Is ETACS-ECU connector C-217 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. If the functions described in "CIRCUIT
OPERATION" work normally, the input signal from the
key reminder switch should be normal.
Page 435 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-435
STEP 6. Check the wiring harness between key reminder
switch connector C-310 (terminal 6) and ETACS-ECU
connector C-217 (terminal 30).
Q: Is the wiring harness between key reminder switch
connector C-310 (terminal 6) and ETACS-ECU connector
C-217 (terminal 30) in good condition?
YES : Go to Step 7.
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 key reminder
switch should be normal.
STEP 7. Check for continuity between key reminder switch
connector C-310 terminal 4 and each of the other terminals
as well as terminal 6 and each of the other terminals.
(1) Disconnect key reminder switch connector C-310 and
measure the resistance available at the equipment side of
the connector.
(2) Check for continuity between key reminder switch
connector C-310 terminal 4 and each of the other terminals
as well as terminal 6 and each of the other terminals.
Q: Does continuity exist between the terminals?
NO : Replace the ETACS-ECU. If the functions described
in "CIRCUIT OPERATION" work normally, the input
signal from the key reminder switch should be normal.
YES : Replace the key reminder switch. If the functions
described in "CIRCUIT OPERATION" work normally,
the input signal from the key reminder switch should
be normal.
Page 436 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-436
INSPECTION PROCEDURE N-2: ETACS-ECU does not receive any signal from the hazard warning
lamp switch.
.
CIRCUIT OPERATION
The ETACS-ECU operates the following functions or
systems according to signal from the hazard warning
lamp switch:
Turn-signal lamp buzzer
Hazard warning lamp
Keyless entry system (registering the encrypted
code)
.
TECHNICAL DESCRIPTION (COMMENT)
If the signal is not normal, the equipment or systems
described in "CIRCUIT OPERATION" do not work
normally.
.
TROUBLESHOOTING HINTS
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
The hazard warning lamp switch may be defec-
tive
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
DIAGNOSIS
Required Special Tool:
MB991223: Harness Set
STEP 1. Check hazard warning lamp switch connector
C-08 for loose, corroded or damaged terminals, or
terminals pushed back in the connector.
Q: Is hazard warning lamp switch connector C-08 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. If the equipment described in "CIRCUIT
OPERATION" work normally, the input signal from the
hazard warning lamp switch should be normal.
Page 437 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-437
STEP 2. Check the hazard warning lamp switch.
Remove the hazard warning lamp switch. Refer to GROUP
54A, Hazard Warning Light Switch P.54A-168. Then check
continuity between the switch terminals.
Q: Is the hazard warning lamp switch in good condition?
YES : Go to Step 3.
NO : Replace the hazard warning lamp switch. If the
equipment described in "CIRCUIT OPERATION",
work normally the input signal from the hazard
warning lamp switch should be normal.
STEP 3. Check the ground circuit to the hazard warning
lamp switch. Measure the resistance at hazard warning
lamp switch connector C-08.
(1) Disconnect hazard warning lamp switch connector C-08
and measure the resistance available at the wiring harness
side of the connector.
(2) Measure the resistance value between terminal 2 and
ground.
The resistance should be 2 ohms or less.
Q: Is the measured resistance 2 ohms or less?
YES : Go to Step 5.
NO : Go to Step 4. SWITCH
POSITIONTESTER
CONNECTIONSPECIFIED
CONDITION
Released 1
2 Open circuit
Pressed 1
2 Less than 2 ohms
Page 438 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-438
STEP 4. Check the wiring harness between hazard warning
lamp switch connector C-08 (terminal 2) and ground.
Q: Is the wiring harness between hazard warning lamp
switch connector C-08 (terminal 2) 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. If the
equipment described in "CIRCUIT OPERATION" work
normally, the input signal from the hazard warning
lamp switch should be normal.
STEP 5. 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 6.
NO : Repair or replace the damaged component(s). Refer
to GROUP 00E, Harness Connector Inspection
P.00E-2. If the equipment described in "CIRCUIT
OPERATION" work normally, the input signal from the
hazard warning lamp switch should be normal.
Page 439 of 1500
INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-439
STEP 6. Check the wiring harness between hazard warning
lamp switch connector C-08 (terminal 1) and ETACS-ECU
connector C-218 (terminal 49).
Q: Is the wiring harness between hazard warning lamp
switch connector C-08 (terminal 1) and ETACS-ECU
connector C-218 (terminal 49) in good condition?
YES : Replace the ETACS-ECU. If the equipment described
in "CIRCUIT OPERATION" work normally, the input
signal from the hazard warning lamp switch 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
equipment described in "CIRCUIT OPERATION" work
normally, the input signal from the hazard warning
lamp switch should be normal.
Page 440 of 1500

INPUT SIGNAL PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-440
INSPECTION PROCEDURE N-3: ETACS-ECU does not receive any signal from any of the door
switches.
.
CIRCUIT OPERATION
The ETACS-ECU operates the following functions or
systems according to signal from the front or rear
door switches:
Light reminder tone alarm function
switch (RH)>
Door ajar warning buzzer
Ignition key reminder tone alarm
switches>
Power window timer function
switches>
Sunroof timer function
Headlamp automatic shutdown function
door switch (RH)>
Keyless entry system
Timer lock
Dome lamp
Interior lamp automatic-shutdown function
door switches>
Ignition key hole illumination lamp
switch (RH)>
Door-ajar indicator lamp
.
TECHNICAL DESCRIPTION (COMMENT)
If the signal is not normal, the functions or systems
described in "CIRCUIT OPERATION" do not work
normally. If the signal is not normal, the front or rear
door switches or the ETACS-ECU may be defective.
.
TROUBLESHOOTING HINTS
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
The front or rear door switches may be defective
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
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