Identifying condition LEXUS LS430 2003 Factory Repair Manual

Fig. 8: Identifying Terminals Of Climate Control ECU - LH (FR)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
a. Disconnect the C20 and S48 blower connectors.
b. Measure the voltage and resistance of the wire harness side connectors.
Standard:
TERMINAL DESCRIPTION AND SPECIFIED CONDITION
Symbols
(Terminal
No.)Wiring
ColorTerminal
DescriptionConditionSpecified
Condition
E (C20 - 8) -
Body groundW-B -
Body
ground
GroundAlwaysBelow 1 ohms
IG (C20 -7) -
Body groundB - Body
groundPower sourceIgnition switch ON10 to 14 V
V5 (C20 - 13)
- VG (C20 - 9)GR-R - LPower supply for
volume switchAlways5 kohms
VS (C20 - 12)
- VG (20 - 9)R-B - LVolume switch signalTurn volume switch: Max0 ohms --> 5
kohms
TB5 (C20 - 4)
- TBS (20 - 3)L-Y -
BR-WSeatback temperature
sensorSeatback temperature: 10°C --
> 30°C (50°F --> 86°F)Approx. 3.7
kohms -->
Approx. 1.7

2.CHECK SEAT CLIMATE CONTROL BLOWER RH (FR) (CLIMATE CONTROL ECU)
Fig. 9: Identifying Terminals Of Climate Control ECU
- RH (FR)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
a. Disconnect the C21 and S49 blower connectors.
b. Measure the voltage and resistance of the wire harness side connectors.
Standard:
TERMINAL DESCRIPTION AND SPECIFIED CONDITION
Symbols
(Terminal
No.)Wiring
ColorTerminal DescriptionConditionSpecified
Condition
E (C21-8) -
Body groundW-B -
Body
ground
GroundAlwaysBelow 1 ohms
IG (C21-7) -
Body groundG - Body
groundPower sourceIgnition switch ON10 to 14 V
V5 (C21-13) -
VG (C21-9)BR-Y -
V-RPower source for
volume switchAlways5 kohms
VS (C21-12) -
VG (21-9)B-O - V-
RVolume switch signalTurn volume switch: Max.
COOL --> Max. WARM0 ohms --> 5
kohms
TB5 (C21-4) - Seatback temperature Turn volume switch: 10°C -->
Approx. 3.7
kohms -->

Fig. 10: Identifying Terminals Of Climate Control ECU - LH (RR)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
a. Disconnect the C27 and C28 blower connectors.
b. Measure the voltage and resistance of the wire harness side connectors.
Standard:
TERMINAL DESCRIPTION AND SPECIFIED CONDITION
If the result is not as specified, there ma
y be a malfunction on the wire harness side.
Symbols
(Terminal No.)Wiring
ColorTerminal
DescriptionConditionSpecified Condition
GND (C27-11) -
Body groundW-B -
Body
ground
GroundAlwaysBelow 1 ohms
IG (C27-10) -
Body groundR-B - Body
groundPower sourceIgnition switch ON10 to 14 V
SW (C27-8) -
Body groundL - Body
groundClimate control
switchTurn the climate control
switch ONBelow 1 ohms
V5 (C27-18) -
VG (C27-16)Y-R - PVolume switchAlways5 kohms
VS (C27-17) -
VG (C27-16)GR-R - PVolume switch
signalRear left volume switch:
Max. COOL --> Max.
WARM
0 ohms --> 5 kohms
TB5 (C28-7) -
TBS (C28-16)G-Y - RSeatback
temperatureSeatback temperature: 10°
C --> 30°C (50°F --> 86°F)Approx. 3.7 kohms -
-> Approx. 1.7
kohms
H5 (C28-5) - HS
(C28-14)L-B - Y-RSeat cushion
temperature sensorSeat cushion temperature:
10°C --> 30°C (50°F -->
86°F)Approx. 3.7 kohms -
-> Approx. 1.7
kohms
TC5 (C28-6) -
TCS (C28-15)BR-R - P-
BHeater
temperature sensorHeater temperature: 10°C -
-> 30°C (50°F --> 86°F)Approx. 3.7 kohms -
-> Approx. 1.7
kohms

HINT:
*: For vehicles with a front seat climate control system
If the result is not as specified, the ECU may have a malfunction.
4.SEAT CLIMATE CONTROL BLOWER RH (RR) (CLIMATE CONTROL ECU)
Fig. 11: Identifying Terminals Of Climate Control ECU
- RH (RR)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
a. Disconnect the C29 and C30 blower connectors.
b. Measure the voltage and resistance of the wire harness side connector.
Standard:
TERMINAL DESCRIPTION AND SPECIFIED CONDITION
> Max. WARM
E (C28-8) - Body
groundB-R - Body
groundGround for seat heaterAlwaysBelow 1 V
IDL (C28-3) -
Body groundG - Body
groundEngine idle-up signal
Ignition switch: ON Turn
climate control switch: OFF --
> ON10 to 14 V --
> 0 V
Symbols
(Terminal No.)Wiring
ColorTerminal
DescriptionConditionSpecified Condition
GND (C29-11) -
Body groundW-B -
Body
ground
GroundAlwaysBelow 1 ohms
IG (C29-10) -
Body groundR-B - Body
groundPower sourceIgnition switch ON10 to 14 V
SW (C29-8) -
Body groundV-R -
Body Climate control
switchTurn climate control
switch ONBelow 1 ohms

Fig. 13: Identifying DLC3 Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
TERMINAL DESCRIPTION AND SPECIFIED CONDITION
HINT:
Connect the cable of the hand-held tester (with CAN VIM) to the DLC3, turn the ignition switch ON and
attempt to use the hand-held tester. If the screen displays the message UNABLE TO CONNECT TO
VEHICLE, there is a problem either with the vehicle or with the tester.
If communication is normal when the tester is connected to another vehicle, inspect the DLC3 on
the original vehicle.
If communication is still impossible when the tester is connected to another vehicle, the problem is
probably in the tester itself. Consult the Service Department listed in the tester's instruction manual.
Symbols (Terminals No.)Terminal DescriptionConditionSpecified condition
SIL (7) - SG (5)Bus "+" lineDuring transmissionPulse generation
CG (4) - Body groundChassis groundAlwaysBelow 1 ohms
SG (5) - Body groundSignal groundAlwaysBelow 1 ohms
BAT (16) - Body groundBattery positiveAlways11 to 14 V

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

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. 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. 41: 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
15.INSPECT SEAT HEATER (THERMISTOR)
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. Disconnect the S60 or S61 heater connector.
b. Check the resistance between the terminals of the heater.
Standard:
Rear LH
TESTER CONNECTION AND SPECIFIED CONDITION - REAR LH
Rear RH
TESTER CONNECTION AND SPECIFIED CONDITION - REAR RH
Tester ConnectionAmbient TemperatureSpecified Condition
S60-2 (H5) - S60-4 (HS)10°C (50°F)Approx. 3.7 kohms
S60-2 (H5) - S60-4 (HS)25°C (77°F)Approx. 2 ohms
S60-2 (H5) - S60-4 (HS)30°C (86°F)Approx. 1.7 ohms
Tester ConnectionAmbient TemperatureSpecified Condition
S61-2 (H5) - S61-4 (HS)10°C (50°F)Approx. 3.7 kohms
S61-2 (H5) - S61-4 (HS)25°C (77°F)Approx. 2 ohms
S61-2 (H5) - S61-4 (HS)30°C (86°F)Approx. 1.7 ohms