2003 LEXUS LS430 air conditioning

Fig. 169: Inspecting Rear Air Conditioning Amplifier (IG - GND)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
3.CHECK HARNESS AND CONNECTOR (REAR AIR CONDITIONING AMPLIFIER -
BATTERY) (SEE ELECTRONIC CIRCUIT INSPECTION PROCEDURE
)
a. Disconnect the rear A/C amplifier connector.
b. Measure the voltage according to the value (s) in the table below.
Standard:
REAR AIR CONDITIONING AMPLIFIER -BATTERY VOLTAGE
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
Tester connectionConditionSpecified condition
A46-10 (IG) - Body groundIgnition switch OFF --> ONBelow 1.0V --> 10 to 14 V

Fig. 170: Checking Harness And Connector (Rear Air Conditioning Amplifier -Battery)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: Go to next step
4.CHECK HARNESS AND CONNECTOR (REAR AIR CONDITIONING AMPLIFIER - BODY
GROUND) (SEE ELECTRONIC CIRCUIT INSPECTION PROCEDURE
)
a. Measure the resistance according to the value (s) in the table below.
Standard:
REAR AIR CONDITIONING AMPLIFIER - BODY GROUND RESISTANCE
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
Tester connectionConditionSpecified condition
A46-6 (GND) - Body groundAlwaysBelow 1 ohms

Fig. 171: Checking Harness And Connector (Rear Air Conditioning Amplifier - Body Ground)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: REPLACE REAR AIR CONDITIONING AMPLIFIER (SEE OVERHAUL
)
CIRCUIT DESCRIPTION
The luggage room J/B ECU requests the rear A/C amplifier to operate the rear blower motor and controls its
operation via the rear blower resistor in this circuit.
WIRING DIAGRAM

NG: Go to STEP 2
Fig. 173: Inspecting Luggage Room J/B ECU (RHR, RFR
- Body Ground)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: Go to STEP 4
2.INSPECT AIR CONDITIONING AMPLIFIER (RHR, RFR1)
a. Remove the A/C amplifier with connectors still connected.
b. Turn the ignition switch to the ON position.
c. Measure the voltage according to the value (s) in the table below.
Standard:
AIR CONDITIONING AMPLIFIER (RHR, RFR1) VOLTAGE
L14-18 (RHR) - Body groundRear blower switch to LO position10 to 14 V
L14-18 (RHR) - Body groundRear blower switch to HI position10 to 14 V
L14-19 (RFR) - Body groundRear blower switch to OFF positionBelow 1 V
L14-19 (RFR) - Body groundRear blower switch to LO positionBelow 1 V
L14-19 (RFR) - Body groundRear blower switch to HI position10 to 14 V

NG: Go to STEP 4
Fig. 174: Inspecting Air Conditioning Amplifier (RHR, RFR1)

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: Go to next step
3.CHECK HARNESS AND CONNECTOR (LUGGAGE ROOM J/B - REAR AIR CONDITIONING
AMPLIFIER) (SEE ELECTRONIC CIRCUIT INSPECTION PROCEDURE
)
a. Measure the resistance accordin
g to the value (s) in the table below.
Tester connectionConditionSpecified condition
A46-16 (RHR) - Body groundRear blower switch to OFF positionBelow 1 V
A46-16 (RHR) - Body groundRear blower switch to LO position10 to 14 V
A46-16 (RHR) - Body groundRear blower switch to HI position10 to 14 V
A46-15 (RFR1) - Body groundRear blower switch to OFF positionBelow 1 V
A46-15 (RFR1) - Body groundRear blower switch to LO positionBelow 1 V
A46-15 (RFR1) - Body groundRear blower switch to HI position10 to 14 V

Standard:
LUGGAGE ROOM J/B - REAR AIR CONDITIONING AMPLIFIER RESISTANCE
Tester connectionConditionSpecified condition
RHR (L14-18) - RHR (A46-16)AlwaysBelow 1 ohms
RHR (L14-18) - Body groundAlways10 kohms or higher
RFR (L14-19) - RFR1 (A46-15)AlwaysBelow 1 ohms
RFR (L14-19) - Body groundAlways10 kohms or higher

Fig. 175: Checking Harness And Connector (Luggage Room J/B - Rear Air Conditioning
Amplifier)

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: Go to next step
REPLACE LUGGAGE ROOM J/B
4.INSPECT AIR CONDITIONING AMPLIFIER (RHI, RLO, RSLO)
a. Remove the A/C amplifier with connectors still connected.
b. Turn the ignition switch to the ON position.
c. Measure the voltage according to the value (s) in the table below.
Standard:
AIR CONDITIONING AMPLIFIER (RHI, RLO, RSLO) VOLTAGE
Tester connectionConditionSpecified condition
A46-8 (RHI) - Body groundRear blower switch to OFF positionBelow 1 V
A46-8 (RHI) - Body groundRear blower switch to LO position10 to 14 V
A46-8 (RHI) - Body groundRear blower switch to HI position10 to 14 V
A46-1 (RLO) - Body groundRear blower switch to OFF positionBelow 1 V
A46-1 (RLO) - Body groundRear blower switch to LO positionBelow 1 V
A46-1 (RLO) - Body groundRear blower switch to HI position10 to 14 V
A46-2 (RSLO) - Body groundRear blower switch to OFF positionBelow 1 V
A46-2 (RSLO) - Body groundRear blower switch to LO position10 to 14 V
A46-2 (RSLO) - Body groundRear blower switch to HI positionBelow 1 V