2003 LEXUS LS430 air condition

Fig. 151: Checking Harness And Connector (Air Conditioning Amplifier - Battery)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: Go to next step
4.CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BODY
GROUND) (SEE ELECTRONIC CIRCUIT INSPECTION PROCEDURE
)
a. Measure the resistance according to the value (s) in the table below.
Standard:
AIR CONDITIONING AMPLIFIER - BODY GROUND RESISTANCE
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
Tester connectionConditionSpecified condition
A11-1 (GND) - Body groundAlwaysBelow 1 ohms

Fig. 152: Checking Harness And Connector (Air Conditioning Amplifier - Body Ground)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: REPLACE AIR CONDITIONING AMPLIFIER (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
This is the power source for the A/C amplifier and servomotors, etc.
WIRING DIAGRAM

Fig. 153: ACC Power Source Circuit
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.INSPECT AIR CONDITIONING AMPLIFIER (ACC - BODY GROUND)
a. Remove the A/C amplifier assy with connectors still connected.
b. Measure the voltage according to the value (s) in the table below.
Standard:
AIR CONDITIONING AMPLIFIER (ACC - BODY GROUND) VOLTAGE
NG: Go to STEP 2
Tester connectionConditionSpecified condition
A11-3 (ACC) - Body groundTurn the ignition switch to the ACC position10 to 14 V

Fig. 154: Inspecting Air Conditioning Amplifier (ACC - Body Ground)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE
2.INSPECT FUSE (P-ACC)
a. Remove the P-ACC fuse from the passenger side J/B.
b. Measure the resistance according to the value (s) in the table below.
Standard:
FUSE (P-ACC) RESISTANCE
NG: CHECK FOR SHORT IN ALL HARNESSES AND COMPONENTS CONNECTED TO
FAILURE FUSE
Tester itemConditionSpecified condition
P-ACC fuseAlwaysBelow 1 ohms

Fig. 155: Identifying Location Of Fuse (P-ACC)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: REPAIR OR REPLACE HARNESS OR CONNECTOR (AIR CONDITIONING
AMPLIFIER - BATTERY)
CIRCUIT DESCRIPTION
The blower motor is operated by signals from the A/C amplifier assy. Blower motor speed signals are
transmitted by changes in the duty ratio.
Duty Ratio
The duty ratio is the ratio of the period of continuity in one cycle. For example, if A is the period of continuity
in one cycle, B is the period of non-continuity.
The blower motor controller controls the blower motor speed.

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

b. Turn the radio and receiver assy on.
c. Set the radio channels and register them.
d. Turn the ignition switch off.
e. Turn the ignition switch to the ON position.
f. Turn the radio and receiver assy on.
g. Check if the registered memory is deleted or not.
OK:
The registered memory is not deleted.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (DRIVER SIDE J/B - BATTERY)
OK: Go to next step
4.INSPECT FUSE (HEATER)
a. Remove the HEATER fuse from the FL block.
b. Measure the resistance according to the value (s) in the table below.
Standard:
FUSE (HEATER) RESISTANCE
NG: CHECK FOR SHORT IN ALL HARNESSES AND COMPONENTS CONNECTED TO
FAILURE FUSE
Tester itemConditionSpecified condition
HEATER fuseAlwaysBelow 1 ohms

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