2003 LEXUS LS430 climate control

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 -->

HINT:
*1: For vehicles with a rear seat heater system
*2: For vehicles with a rear seat climate control system
If the result is not as specified, there may be a malfunction on the wire harness side.
c. Reconnect the C21 and S49 blower connectors.
d. Measure the voltage of the connector.
Standard:
TERMINAL DESCRIPTION AND SPECIFIED CONDITION
If the result is not as specified, the ECU may have a malfunction.
3.SEAT CLIMATE CONTROL BLOWER LH (RR) (CLIMATE CONTROL ECU)
TBS (C21-3)G-Y - Rsensor30°C (50°F --> 86°F)Approx. 1.7
kohms
TC5 (S49-2) -
TCS (S49-1)B -BSeat cushion
temperature sensorTurn the volume switch: 10°C
--> 30°C (50°F --> 86°F)
Approx. 3.7
kohms -->
Approx. 1.7
kohms
DSID (C21-6)
- Body groundGR -
Body
groundRear seat heater
switch*1 Rear seat
climate control
switch*2Ignition switch: ON Turn rear
seat heater switch*1 or rear
seat climate control switch*2
OFF --> ON
0 V --> 10 to 14
V
Symbols
(Terminal No.)Wiring
ColorTerminal DescriptionConditionSpecified
Condition
IND (C21-5) -
Body groundY-B - Body
groundClimate control switch
indicatorIgnition switch: ON Turn
climate control switch: OFF -->
ON0 V --> 10 to
14 V
TDB+ (C21-14) -
Body groundLG-B -
Body
groundPower supply for seatback
Peltier element (WARM)Ignition switch: ON Turn
climate control switch: OFF -->
Max. WARM0 V --> 10 to
14 V
TDB- (C21-1) -
Body groundB - Body
groundPower supply for seatback
Peltier element (COOL)Ignition switch: ON Turn
climate control switch: OFF -->
Max. COOL0 V --> 10 to
14 V
TDC+ (S49-3) -
Body groundL - Body
groundPower supply for seat
cushion Peltier element
(WARM)Ignition switch: ON Turn
climate control switch: OFF -->
Max. WARM0 V --> 10 to
14 V
TDC- (S49-6) -
Body groundY - Body
groundPower supply for seat
cushion Peltier element
(COOL)Ignition switch: ON Turn
climate control switch: OFF -->
Max. COOL0 V --> 10 to
14 V

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

c. Reconnect the C27 and C28 blower connectors.
d. Measure the voltage of the connectors.
Standard:
TERMINAL DESCRIPTION AND SPECIFIED CONDITION
Symbols
(Terminal No.)Wiring
ColorTerminal DescriptionConditionSpecified
Condition
IND (C27-7) -
Body groundR-B - Body
groundClimate control switch
indicator (rear)Ignition switch: ON Turn
climate control switch: OFF --
> ON0 V --> 10 to
14 V
INDC (C27-6)* -
Body groundG-B - Body
groundClimate control switch
indicator (front)Ignition switch: ON Turn
climate control switch: OFF --
> ON0 V --> 10 to
14 V
TDB+ (C28-1) -
Body groundLG-B -
Body
groundPower supply for seatback
Peltier element (WARM)Ignition switch: ON Turn
climate control switch: OFF --
> Max. WARM0 V --> 10 to
14 V
TDB- (C28-2) -
Body groundB - Body
groundPower supply for seatback
Peltier element (COOL)Ignition switch: ON Turn
climate control switch: OFF --
> Max. WARM0 V --> 10 to
14 V
TDC+ (C28-10) -
Body groundY - Body
groundPower supply for seat
cushion Peltier element
(WARM)Ignition switch: ON Turn
climate control switch: OFF --
> Max. WARM0 V --> 10 to
14 V
TDC- (C28-11) -
Body groundBR-W -
Body
groundPower supply for seat
cushion Peltier element
(COOL)Ignition switch: ON Turn
climate control switch: OFF --
> Max. COOL0 V --> 10 to
14 V
BBS (C27-3) -
Body groundY-B - Body
groundMonitor of fan motor
(seatback)Ignition switch: ON Turn
climate control switch: OFF --
> ON (airflow)0 V --> 10 to
14 V
BCS (C27-13) -
Body groundV - Body
groundMonitor of fan motor (seat
cushion)Ignition switch: ON Turn
climate control switch: OFF --
> ON (airflow)0 V --> 10 to
14 V
BFB+ (C27-2) -
Body groundG-W -
Body
groundPower supply for fan
motor (seatback)Ignition switch: ON Turn
climate control switch: OFF --
> ON (airflow)0 V --> 10 to
14 V
BFC+ (C27-12) -
Body groundL - Body
groundPower supply for fan
motor (seat cushion)Ignition switch: ON Turn
climate control switch: OFF --
> ON (airflow)0 V --> 10 to
14 V
BFB- (C28-9) -
Body groundGR-R -
Body
groundGround for fan motor
(seatback)AlwaysBelow 1 V
BFC- (C27-1) -
Body groundO - Body
groundGround for fan motor (seat
cushion)AlwaysBelow 1 V
B (C28-18) -
Body groundV-G - Body
groundPower supply for seat
heaterIgnition switch: ON Turn
climate control switch: OFF --0 V --> 10 to
14 V

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

If the result is not as specified, there may be a malfunction on the wire harness side.
c. Reconnect the C29 and C30 blower connectors.
d. Measure the voltage of the connectors.
Standard:
TERMINAL DESCRIPTION AND SPECIFIED CONDITION
ground
V5 (C29-18) -
VG (C29-16)L-R - BR-
YVolume switchAlways5 kohms
VS (C29-17) -
VG (C29-16)GR - BR-YVolume switch
signalVolume switch: 10°C -->
30°C (50°F --> 86°F)0 ohms --> 5 kohms
TB5 (C30-7) -
TBS (C30-16)G-Y - RSeatback
temperature sensorSeatback temperature: 10°
C --> 30°C (50°F --> 86°F)Approx. 3.7 kohms -
-> Approx. 1.7
kohms
H5 (C30-5) - HS
(C30-14)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 (C30-6) -
TCS (C30-15)BR-R - P-
BSeat heater
temperature sensorHeater temperature: 10°C -
-> 30°C (50°F --> 86°F)Approx. 3.7 kohms -
-> Approx. 1.7
kohms
Symbols
(Terminal No.)Wiring
ColorTerminal DescriptionConditionSpecified
Condition
IND (C29-7) -
Body groundB-O - Body
groundClimate control switch
indicator (rear)Ignition switch: ON Turn
climate control switch: OFF --
> ON0 V --> 10 to
14 V
INDC (C29-6)* -
Body groundG-B - Body
groundClimate control switch
indicator (front)Ignition switch: ON Turn
climate control switch: OFF --
> ON0 V --> 10 to
14 V
TDB+ (C30-1) -
Body groundLG-B -
Body
groundPower supply for seatback
Peltier element (WARM)Ignition switch: ON Turn
climate control switch: OFF --
> Max. WARM0 V --> 10 to
14 V
TDB- (C30-2) -
Body groundB - Body
groundPower supply for seatback
Peltier element (COOL)Ignition switch: ON Turn
climate control switch: OFF --
> Max. COOL0 V --> 10 to
14 V
TDC+ (C30-10) -
Body groundY - Body
groundPower supply for seat
cushion Peltier element
(WARM)Ignition switch: ON Turn
climate control switch: OFF --
> Max. WARM0 V --> 10 to
14 V
TDC- (C30-11) -
Body groundBR-W -
Body
groundPower supply for seat
cushion Peltier element
(COOL)Ignition switch: ON Turn
climate control switch: OFF --
> Max. COOL0 V --> 10 to
14 V
BBS (C29-3) -
Body groundY-B - Body
groundMonitor of fan motor
(seatback)Ignition switch: ON Turn
climate control switch: OFF --0 V --> 10 to
14 V

HINT:
*: For vehicles with a front seat climate control system
If the result is not as specified, the ECU may have a malfunction.
> ON (airflow)
BCS (C29-13) -
Body groundV - Body
groundMonitor of fan motor (seat
cushion)Ignition switch: ON Turn
climate control switch: OFF --
> ON (airflow)0 V --> 10 to
14 V
BFB+ (C29-2) -
Body groundG-W -
Body
groundPower supply for fan
motor (seatback)Ignition switch: ON Turn
climate control switch: OFF --
> ON (airflow)0 V --> 10 to
14 V
BFC+ (C29-12) -
Body groundL - Body
groundPower supply for fan
motor (seat cushion)Ignition switch: ON Turn
climate control switch: OFF --
> ON (airflow)0 V --> 10 to
14 V
BFB- (C30-9) -
Body groundGR-R -
Body
groundGround for fan motor
(seatback)AlwaysBelow 1 V
BFC- (C29-1) -
Body groundO - Body
groundGround for fan motor (seat
cushion)AlwaysBelow 1 V
B (C30-18) -
Body groundV-G - Body
groundPower supply for seat
heaterIgnition switch: ON Turn
climate control switch: OFF --
> Max. WARM0 V --> 10 to
14 V
E (C30-8) - Body
groundB-R - Body
groundGround for seat heaterAlwaysBelow 1 V
IDL (C30-3) -
Body groundG - Body
groundEngine idle-up signal
Ignition switch: ON Turn
climate control switch: OFF --
> ON10 to 14 V --
> 0 V

Fig. 12: Problem Symptoms Table
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
1.DESCRIPTION
a. Climate control seat system data and the Diagnostic Trouble Code (DTCs) can be read in the Data
Link Connector 3 (DLC3) of the vehicle. When the system seems to be malfunctioning, use the
hand-held tester to check for malfunctions and perform repairs.
2.CHECK DLC3
The vehicle's ECU uses the ISO 15765-4 communication protocol. The terminal arrangement of the
DLC3 complies with SAE J1962 and matches the ISO 15765-4 format.