2003 LEXUS LS430 Identifying ac

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

Fig. 30: Identifying Seat Climate Control Blower Connector Terminals And Climate Control
Switch Connector Terminals
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)
4.INSPECT CLIMATE CONTROL SWITCH (SEE INSPECTION
)
NG: REPLACE CLIMATE CONTROL SWITCH
OK: Go to next step
5.CHECK WIRE HARNESS (SEAT CLIMATE CONTROL BLOWER (CLIMATE CONTROL
ECU) - CLIMATE CONTROL SWITCH)
HINT:
When the indicator of rear left side is blinking, check the rear left side connector. When the indicator of

Fig. 31: Identifying Seat Climate Control Blower Connector Terminals And Climate Control
Switch Connector Terminals
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
As a result of an short circuit, the ECU may not be able to provide 5 V of power voltage to the seat climate
controller thermistor circuit, climate control switch's volume control circuit or rear seat heater thermistor circuit.
If this happens, all output will be stopped and the indicator illuminates according to blinking pattern 3.
WIRING DIAGRAM

Fig. 34: 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
4.CHECK WIRE HARNESS (SEAT CLIMATE CONTROL BLOWER (CLIMATE CONTROL
ECU) - BODY GROUND)
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. Measure the voltage 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
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

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

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