2003 LEXUS LS430 climate control

TESTER CONNECTION AND SPECIFIED CONDITION - DRIVER SIDE
Passenger side
TESTER CONNECTION AND SPECIFIED CONDITION - PASSENGER SIDE
Fig. 35: Identifying Seat Climate Control Blower Connector Terminals

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPLACE SEAT CLIMATE CONTROL CONTROLLER (CLIMATE CONTROL ECU)
OK: Go to next step
5.INSPECT SEAT CLIMATE CONTROL CONTROLLER (THERMISTOR OF SEATBACK)
Tester ConnectionConditionSpecified Condition
C20-13 (V5) - Body GroundIgnition switch ON5 V
Tester ConnectionConditionSpecified Condition
C21-13 (V5) - Body GroundIgnition switch ON5 V

(SEE INSPECTION )
NG: REPLACE SEAT CLIMATE CONTROL CONTROLLER
OK: Go to next step
6.CHECK WIRE HARNESS (SEAT CLIMATE CONTROL BLOWER (CLIMATE CONTROL
ECU) - SEAT CLIMATE CONTROLLER)
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 C20 or C21 blower connector.
b. Disconnect the S34 or S35 controller connector.
c. Measure the resistance of the wire harness side connectors.
Standard:
Driver side
TESTER CONNECTION AND SPECIFIED CONDITION - DRIVER SIDE
Passenger side
TESTER CONNECTION AND SPECIFIED CONDITION - PASSENGER SIDE
Tester ConnectionSpecified Condition
C20-3 (TBS) - S34-2 (TBS)Below 1 ohms
C20-4 (TB5) - S34-3 (TB5)Below 1 ohms
Tester ConnectionSpecified Condition
C21-3 (TBS) - S35-2 (TBS)Below 1 ohms
C21-4 (TB5) - S35-3 (TB5)Below 1 ohms

Fig. 36: 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 WIRE HARNESS (SEAT CLIMATE CONTROL BLOWER (CLIMATE CONTROL
ECU) - SEAT CLIMATE CONTROLLER)
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 controller connector.
b. Measure the resistance of the wire harness side connector.
Standard:
Driver side
TESTER CONNECTION AND SPECIFIED CONDITION - DRIVER SIDE
Passenger side
TESTER CONNECTION AND SPECIFIED CONDITION - PASSENGER SIDE
HINT:
As the temperature increases, the resistance decreases.
Tester ConnectionAmbient TemperatureSpecified Condition
S48-2 (TB5) - S48-1 (TBS)10°C (50°F)Approx. 3.7 kohms
S48-2 (TB5) - S48-1 (TBS)25°C (77°F)Approx. 2 kohms
S48-2 (TB5) - S48-1 (TBS)30°C (86°F)Approx. 1.7 kohms
Tester ConnectionAmbient TemperatureSpecified Condition
S49-2 (TB5) - S49-1 (TBS)10°C (50°F)Approx. 3.7 kohms
S49-2 (TB5) - S49-1 (TBS)25°C (77°F)Approx. 2 kohms
S49-2 (TB5) - S49-1 (TBS)30°C (86°F)Approx. 1.7 kohms

Fig. 37: Identifying Seat Climate Controller Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPLACE SEAT CLIMATE CONTROL CONTROLLER
OK: REPLACE SEAT CLIMATE CONTROL CONTROLLER (CLIMATE CONTROL ECU)
8.INSPECT REAR SEAT HEATER SWITCH (REAR) (SEE INSPECTION
)
NG: REPLACE FRONT SEAT HEATER SWITCH
OK: Go to next step
9.CHECK WIRE HARNESS (SEAT CLIMATE CONTROL BLOWER (CLIMATE CONTROL
ECU) - CLIMATE CONTROL SWITCH)
HINT:

Fig. 38: Identifying Seat Climate Control Blower Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
OK: Go to next step
10.CHECK WIRE HARNESS (SEAT CLIMATE CONTROL BLOWER (CLIMATE CONTROL
ECU) - BODY GROUND)
HINT:
When the rear LH indicator is blinking, check the rear LH side connector. When the rear RH indicator is
blinking, check the rear right RH side connector.
a. Measure the voltage of the wire harness side connector.
Standard:
Rear LH
TESTER CONNECTION AND SPECIFIED CONDITION - REAR LH
Rear RH
TESTER CONNECTION AND SPECIFIED CONDITION - REAR RH
Tester ConnectionConditionSpecified Condition
C27-18 (V5) - Body groundIgnition switch ON, Climate control switch ON5 V
Tester ConnectionConditionSpecified Condition
C29-18 (V5) - Body groundIgnition switch ON, Climate control switch ON5 V

Fig. 39: Identifying Seat Climate Control Blower Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPLACE SEAT CLIMATE CONTROL CONTROLLER (CLIMATE CONTROL ECU)
OK: Go to next step
11.INSPECT SEAT CLIMATE CONTROL CONTROLLER (THERMISTOR OF SEATBACK)
(SEE INSPECTION
)
NG: REPLACE SEAT CLIMATE CONTROL CONTROLLER
OK: Go to next step
12.CHECK WIRE HARNESS (SEAT CLIMATE CONTROL BLOWER (CLIMATE CONTROL
ECU) - SEAT CLIMATE CONTROLLER)
HINT:
When the rear LH indicator is blinking, check the rear LH side connector. When the rear RH indicator is
blinking, check the rear right RH side connector.

Fig. 40: Identifying Seat Climate Control Blower Connector Terminals And Seat Climate