2003 LEXUS LS430 climate control

Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
OK: Go to next step
4.CHECK SEAT CLIMATE CONTROL CONTROLLER (SEAT CUSHION)
HINT:
When the driver side indicator is blinking, check the driver side connector. When the passenger side
indicator is blinking, check the passenger side connector.
a. Disconnect the S48 or S49 connector.
b. Connect terminal 3 (TDC+) and 6 (TDC-) of the climate control ECU connector, as shown in the
illustration.
c. Turn the ignition switch ON.
d. Turn the climate control switch ON, and then check that the climate control switch indicator turns
off.
OK: The indicator turns off

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0b00360048004400570003002600580056004b004c00520051[)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPLACE SEAT CLIMATE CONTROL BLOWER REPAIR SEAT CLIMATE CONTROL
BLOWER (CLIMATE CONTROL ECU)
OK: REPLACE SEAT CLIMATE CONTROLLER (SEAT CUSHION)
5.CHECK SEAT CLIMATE CONTROL CONTROLLER (SEATBACK)
HINT:
When the rear LH indicator is blinking, check the rear LH connector. When the rear RH indicator is
blinking, check the rear RH connector.
a. Disconnect the S52 or S54 controller connector.
b. Connect the wire harness to terminal 4 (TDB-) and 5 (TDB+) of the wire harness side connector.
c. Turn the ignition switch ON.
d. Turn the climate control switch ON, and then check that the climate control indicator continues
blinking.

Result:
RESULT REFERENCE
Fig. 23: Checking Seat Climate Control Controller (Seatback)

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
B: REPLACE SEAT CLIMATE CONTROL CONTROLLER (SEATBACK)
A: Go to next step
6.CHECK WIRE HARNESS (SEAT CLIMATE CONTROL BLOWER (CLIMATE CONTROL
ECU) - SEAT CLIMATE CONTROLLER (SEATBACK))
HINT:
When the rear LH indicator is blinkin
g, check the rear LH connector. When the rear RH indicator is
ResultProceed to
Indicator continues blinkingA
Indicator turns offB

Fig. 24: Identifying Seat Climate Control Blower Connector Terminals And Seat Climate
Controller Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
OK: Go to next step
7.CHECK SEAT CLIMATE CONTROL CONTROLLER (SEAT CUSHION)
HINT:
When the rear LH indicator is blinking, check the rear LH connector. When the rear RH indicator is
blinking, check the rear RH connector.
a. Disconnect the S53 or S55 blower connector.
b. Connect the wire harness to terminal 5 (TDC+) and 4 (TDC-) of the wire harness side connector, as
shown in the illustration.
c. Turn the ignition switch ON.
d. Turn the climate control switch ON, and then check that the climate control indicator turns off.
OK: The indicator turns off

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0b00360048004400570003002600580056004b004c00520051[)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: Go to step 8
OK: REPLACE SEAT CLIMATE CONTROLLER (SEAT CUSHION)
8.CHECK WIRE HARNESS (SEAT CLIMATE CONTROL BLOWER (CLIMATE CONTROL
ECU) - SEAT CLIMATE CONTROLLER (SEAT CUSHION))
HINT:
When the rear LH indicator is blinking, check the rear LH connector. When the rear RH indicator is
blinking, check the rear RH connector.
a. Disconnect the C28 or C30 blower connector.
b. Disconnect the S53 or S55 controller connector.
c. Measure the resistance of between the wire harness side connectors.
Standard:

Fig. 26: Identifying Seat Climate Control Blower Connector Terminals And Seat Climate
Controller Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
OK: Go to next step
9.CHECK SEAT HEATER (SEATBACK) (SEE INSPECTION
)
NG: REPLACE REAR SEATBACK PAD
OK: Go to next step
10.INSPECT SEAT HEATER (SEAT CUSHION) (SEE INSPECTION
)
NG: REPLACE SEAT CUSHION PAD
OK: Go to next step
11.CHECK WIRE HARNESS (SEAT CLIMATE CONTROL BLOWER (CLIMATE CONTROL
ECU) - SEAT HEATER)
HINT:
When the indicator of rear left side is blinking, check the rear left side connector. When the indicator of
rear right side is blinking, check the rear right side connector.
a. Disconnect the C28 or C30 blower connector.
b. Disconnect the S60 or S61 heater connector.
c. Measure the resistance of the wire harness side connectors.
Standard:
Rear LH
TESTER CONNECTION AND SPECIFIED CONDITION - REAR LH
Rear RH
TESTER CONNECTION AND SPECIFIED CONDITION - REAR RH
Tester ConnectionSpecified Condition
C28-8 (E) - S60-3 (E)Below 1 ohms
C28-8 (E) - S60-1 (B)10 kohms or higher
C28-18 (B) - S60-1 (B)Below 1 ohms
C28-18 (B) - S60-3 (E)10 kohms or higher

Fig. 27: Identifying Seat Climate Control Blower Connector Terminals And Seat Heater Connector
Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
OK: Go to next step
12.INSPECT SEAT CLIMATE CONTROL BLOWER (FAN MOTOR OF SEATBACK) (SEE
INSPECTION
)
NG: REPLACE SEAT CLIMATE CONTROL BLOWER (SEATBACK)
OK: Go to next step
13.CHECK WIRE HARNESS (SEAT CLIMATE CONTROL BLOWER (CLIMATE CONTROL
ECU) - SEAT CLIMATE FAN MOTOR)
HINT:
When the indicator of rear left side is blinking, check the rear left side connector. When the indicator of
rear right side is blinking, check the rear right side connector.
a. Disconnect the C27 or C29 blower connector.
b. Disconnect the S56 or S58 motor connector.
c. Measure the resistance of the wire harness side connectors.
Standard:
Rear LH
TESTER CONNECTION AND SPECIFIED CONDITION - REAR LH
Rear RH
TESTER CONNECTION AND SPECIFIED CONDITION - REAR RH
Tester ConnectionSpecified Condition
C27-3 (BBS) - S56-3 (BBS)Below 1 ohms
C27-3 (BBS) - S56-2 (BFB(+))10 kohms or higher
C27-2 (BFB+) - S56-2 (BFB(+))Below 1 ohms
C27-2 (BFB+) - S56-3 (BBS)10 kohms or higher
Tester ConnectionSpecified Condition
C29-3 (BBS) - S58-3 (BBS)Below 1 ohms
C29-3 (BBS) - S58-2 (BFB(+))10 kohms or higher
C29-2 (BFB+) - S58-2 (BFB(+))Below 1 ohms

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
OK: REPLACE SEAT CLIMATE CONTROL BLOWER (CLIMATE CONTROL ECU)
CIRCUIT DESCRIPTION
When the climate control switch's volume control circuit is open or short circuit and abnormal codes are input to
the VS terminal, all output will be stopped and the indicator illuminates according to blinking pattern 2.
WIRING DIAGRAM