2003 LEXUS LS430 air conditioning

DATA LIST / AIR CONDITIONER:
DATA LIST / AIR CONDITIONER
OK:
The display is as specified in the normal condition.
NG: REPLACE AIR CONDITIONING AMPLIFIER (SEE REPLACEMENT
)
OK: Go to next step
2.PERFORM ACTUATOR CHECK

a. Set the actuator check mode (see ACTUATOR CHECK
).
b. Press the blower switch to set the STEP operation.
c. Check the air flow level by hand.
DISPLAY CODE - BLOWER LEVEL
OK:
<0025004f0052005a004800550003004f004800590048004f00030046004b00440051004a004800560003004c0051000300440046004600520055004700440051004600480003005a004c0057004b0003004800440046004b00030047004c00560053004f00
44005c000300460052004700480011[
NG: Go to STEP 2
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN REPLACEMENT

3.INSPECT RADIO AND RECEIVER ASSY
a. Turn the ignition switch to the ON position.
ItemMeasure Item/Display (Range)Normal ConditionDiagnostic
Note
BLOWER
LEVELBlower motor speed level / min.: 0
level max.: 31 levelIncreases in the range between 0 and
31 as the speed increase-
Display CodeBlower level
00
11
214
314
414
514
614
714
814
931

Fig. 158: Identifying Location Of Fuse (Heater)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: Go to next step
5.CHECK HARNESS AND CONNECTOR (BLOWER MOTOR - AIR CONDITIONING
AMPLIFIER) (SEE ELECTRONIC CIRCUIT INSPECTION PROCEDURE
)
a. Measure the resistance according to the value (s) in the table below.
Standard:
BLOWER MOTOR - AIR CONDITIONING AMPLIFIER RESISTANCE
Tester connectionConditionSpecified condition
A11-5 (BLW) -B2-2 (SI)AlwaysBelow 1 ohms
A11-5 (BLW) - Body groundAlways10 kohms or higher

<0029004c004a0011000300140018001c001d00030026004b00480046004e004c0051004a0003002b004400550051004800560056000300240051004700030026005200510051004800460057005200550003000b0025004f0052005a004800550003003000
520057005200550003[- Air Conditioning Amplifier)

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: Go to next step
8.INSPECT BLOWER MOTOR
a. Remove the blower motor.
b. Connect positive (+) lead to terminal 2 of the blower motor connector and negative (-) lead to
terminal 1.
OK: Blower motor operates smoothly.
Fig. 162: Inspecting Blower Motor

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPLACE BLOWER MOTOR
OK: Go to next step
9.INSPECT AIR CONDITIONING AMPLIFIER (BLW - BODY GROUND)
a. Remove the A/C amplifier with connectors still connected.
b. Turn the ignition switch to the ON position.

c. Turn the blower switch on (Lo).
<0029004c004a00110003001400190016001d0003002c005100560053004800460057004c0051004a00030024004c005500030026005200510047004c0057004c00520051004c0051004a0003002400500053004f004c0049004c004800550003000b002500
2f003a0003[
- Body Ground)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
d. Measure the waveform between terminal BLW (A11-5) of the A/C amplifier and body ground.
OK:
Waveform operate as shown in the illustration.
HINT:
Waveform varies with the blower level.
NG: REPLACE AIR CONDITIONING AMPLIFIER (SEE REPLACEMENT
)

Fig. 166: Identifying Location Of Fuse (RR ECU-B)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: CHECK FOR SHORT IN ALL HARNESSES AND COMPONENTS CONNECTED TO
FAILURE FUSE (RR ECU-B)
OK: Go to next step
2.INSPECT REAR AIR CONDITIONING AMPLIFIER (R-B - BODY GROUND)
a. Remove the rear A/C amplifier assy and disconnect the connector.
b. Measure the voltage according to the value (s) in the table below.
Standard:
REAR AIR CONDITIONING AMPLIFIER (R-B - BODY GROUND) VOLTAGE
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (REAR AIR CONDITIONING
AMPLIFIER -BATTERY)
Tester connectionConditionSpecified condition
A46-3 (R-B) - Body groundAlways10 to 14 V

Fig. 167: Inspecting Rear Air Conditioning Amplifier (R-B - Body Ground)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE
CIRCUIT DESCRIPTION
The main power source is supplied to the A/C amplifier when the ignition switch is turned to the ON position.
The power source supplied is used for operating the A/C amplifier and servomotor, etc.
WIRING DIAGRAM

FUSE (RR A/C) RESISTANCE
NG: CHECK FOR SHORT IN ALL HARNESS AND COMPONENTS CONNECTED TO
FAILURE FUSE (RR A/C FUSE)
OK: Go to next step
2.INSPECT REAR AIR CONDITIONING AMPLIFIER (IG - GND)
a. Remove the A/C amplifier assy 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:
REAR AIR CONDITIONING AMPLIFIER (IG - GND) VOLTAGE
NG: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE
Tester itemConditionSpecified condition
RR A/C fuseAlwaysBelow 1 ohms
Tester connectionConditionSpecified condition
A46-10 (IG) -A46-6 (GND)Ignition switch OFF --> ONBelow 1 V --> 10 to 14 V