2003 LEXUS LS430 air condition

a. Connect the hand-held tester to the DLC3.
b. Turn the ignition switch to the ON position and push the hand-held tester main switch on.
c. Select the items below in the DATA LIST, and read the displays on the hand-held tester.
DATA LIST / AIR CONDITIONER:
DATA LIST / AIR CONDITIONER
OK:
The display is as specified in the normal condition.
Result:
AIR CONDITIONER TEST RESULT
B: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
C: REPLACE AIR CONDITIONING AMPLIFIER (SEE REPLACEMENT )
A: Go to next step
2.INSPECT AIR CONDITIONING AMPLIFIER (TPI - SG)
a. Remove the A/C amplifier with connectors still connected.
b. Turn the ignition switch to the ON position.
c. Change the set RECIRC/FRESH to activate the air inlet servomotor.
d. Measure the voltage according to the value (s) in the table below.
Standard:
AIR CONDITIONING AMPLIFIER (TPI - SG) VOLTAGE
Item
Measure Item/Display
(Range)
Normal ConditionDiagnostic Note
A/I DAMP
POSAir inlet damper position /
min.: -14% max.: 113.5%RECIRCULATION: Approx. 0%
FRESH: Approx. 100%-
A/I DAMP
TARGAir inlet damper target /
min.: -14% max.: 113.5%RECIRCULATION: Approx. 0%
FRESH: Approx. 100% HALF-
RECIRCULATION: 43 to 99.5 %-
NGA
OK (Checking from the PROBLEM SYMPTOM TABLE)B
OK (Checking from the DTC)C
Tester connectionConditionSpecified condition
A37-20 (TPI) - A37-19 (SG)RECIRC3.5 to 4.5 V
A37-20 (TPI) - A37-19 (SG)FRESH0.5 to 1.5 V

HINT:
As the air inlet servomotor moves from the RECIRC side to the FRESH side, the voltage decreases
gradually without interruption.
Result:
AIR CONDITIONING AMPLIFIER (TPI - SG) TEST RESULT
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2c0003[
- SG)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
B: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
C: REPLACE AIR CONDITIONING AMPLIFIER (SEE REPLACEMENT )
A: Go to next step
3.INSPECT AIR INLET SERVOMOTOR
NGA
OK (Checking from the PROBLEM SYMPTOMS TABLE)B
OK (Checking from the DTC)C

a. Remove the air inlet servomotor.
b. Measure the resistance according to the value (s) in the table below.
Standard:
AIR INLET SERVOMOTOR RESISTANCE
c. Measure the resistance according to the value (s) in the table below.
HINT:
SEE DTC B1442 AIR INLET DAMPER CONTROL SERVOMOTOR CIRCUIT
for operation
procedure for the air inlet servomotor.
Standard:
AIR INLET SERVOMOTOR RESISTANCE
HINT:
As the air inlet servomotor moves from fresh to recirculation, the resistance decreases gradually without
interruption.
Tester connectionConditionSpecified condition
A41-1 (VZ) - A41-2 (GND)Always4.2 to 7.8 kohms
Tester connectionConditionSpecified condition
A41-3 (PT) - A41-2 (GND)RECIRCULATION3.4 to 6.2 kohms
A41-3 (PT) - A41-2 (GND)FRESH0.8 to 1.6 kohms

Fig. 97: Inspecting Air Inlet Servomotor
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPLACE AIR INLET SERVOMOTOR
OK: Go to next step
4.CHECK HARNESS AND CONNECTOR (AIR INLET SERVOMOTOR - AIR CONDITIONING
AMPLIFIER) (SEE ELECTRONIC CIRCUIT INSPECTION PROCEDURE
)
a. Measure the resistance according to the value (s) in the table below.
Standard:
AIR INLET SERVOMOTOR - AIR CONDITIONING AMPLIFIER RESISTANCE
Tester connectionConditionSpecified condition
A37-20 (TPI) - A41-3 (PT)AlwaysBelow 1 ohms
A37-18 (S5-3) - A41-1 (VZ)AlwaysBelow 1 ohms
A37-19 (SG) - A41-2 (GND)AlwaysBelow 1 ohms
A37-20 (TPI) - Body groundAlways10 kohms or higher
A37-18 (S5-3) - Body groundAlways10 kohms or higher

Fig. 98: Checking Harness And Connector (Air Inlet Servomotor - Air Conditioning Amplifier)

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: REPLACE AIR CONDITIONING AMPLIFIER (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
This sensor detects the position of the cool air bypass servomotor (Max cool damper servomotor) and sends the
appropriate signals to the A/C amplifier. The position sensor is built in the cool air bypass servomotor.

INSPECTION PROCEDURE
1.READ VALUE ON HAND-HELD TESTER
a. Connect the hand-held tester to the DLC3.
b. Turn the ignition switch to the ON position and push the hand-held tester main switch on.
c. Select the item below in the DATA LIST, and read the display on the hand-held tester.
DATA LIST / AIR CONDITIONER:
DATA LIST / AIR CONDITIONER
OK:
The display is as specified in the normal condition.
Result:
AIR CONDITIONER TEST RESULT
B: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
C: REPLACE AIR CONDITIONING AMPLIFIER (SEE REPLACEMENT )
A: Go to next step
2.INSPECT AIR CONDITIONING AMPLIFIER (TPBDr - SG-7)
a. Remove the A/C amplifier with connectors still connected.
b. Turn the ignition switch to the ON position.
c. Change the set temperature to activate the cool air bypass servomotor.
d. Measure the voltage according to the value (s) in the table below.
Standard:
AIR CONDITIONING AMPLIFIER (TPBDr - SG-7) VOLTAGE
ItemMeasure Item/Display (Range)Normal ConditionDiagnostic
Note
A/B DAMP
POS-DCool air bypass damper position (Driver
side) / min.: -14% max.: 113.5%OPEN: Approx. 0 % SHUT:
Approx. 100%-
NGA
OK (Checking from the PROBLEM SYMPTOM TABLE)B
OK (Checking from the DTC)C
Tester connectionConditionSpecified condition
A36-24 (TPBDr) - A36-15 (SG-7)MAX. Hot0.5 to 1.8 V
A36-24 (TPBDr) - A36-15 (SG-7)MAX. Cool3.5 to 4.5 V

HINT:
As the set temperature increases, the voltage decreases gradually without interruption.
Result:
AIR CONDITIONING AMPLIFIER (TPBDR - SG-7) TEST RESULT
Fig. 102: Inspecting Air Conditioning Amplifier (TPBDR
- SG-7)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
B: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
C: REPLACE AIR CONDITIONING AMPLIFIER (SEE REPLACEMENT )
A: Go to next step
3.INSPECT COOL AIR BYPASS SERVOMOTOR
NGA
OK (Checking from the PROBLEM SYMPTOMS TABLE)B
OK (Checking from the DTC)C