LEXUS LS430 2003 Factory Repair Manual

Fig. 108: Inspecting Air Conditioning Amplifier (TPBPA - SG (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
a. Remove the cool air bypass servomotor.
b. Measure the resistance according to the value (s) in the table below.
Standard:
COOL AIR BYPASS SERVOMOTOR RESISTANCE
c. Measure the resistance accordin
g to the value (s) in the table below.
Tester connectionConditionSpecified condition
C25-1 (VZ) - C25-2 (GND)Always4.2 to 7.2 kohms

HINT:
SEE COOL AIR BYPASS DAMPER CONTROL SERVOMOTOR CIRCUIT (PASSENGER
SIDE) for operation procedure for cool air bypass servomotor.
Standard:
COOL AIR BYPASS SERVOMOTOR RESISTANCE
HINT:
As the cool air bypass servomotor moves from the cool side to the hot side, the resistance decreases
gradually without interruption.
Fig. 109: Inspecting Cool Air Bypass Servomotor

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPLACE COOL AIR BYPASS SERVOMOTOR
Tester connectionConditionSpecified condition
C25-3 (PT) - C25-2 (GND)Max. Cool3.33 to 4.03 kohms
C25-3 (PT) - C25-2 (GND)Max. Hot0.80 to 1.60 kohms

OK: Go to next step
4.CHECK HARNESS AND CONNECTOR (COOL AIR BYPASS SERVOMOTOR - AIR
CONDITIONING AMPLIFIER) (SEE ELECTRONIC CIRCUIT INSPECTION PROCEDURE
)
a. Measure the resistance according to the value (s) in the table below.
Standard:
COOL AIR BYPASS SERVOMOTOR - AIR CONDITIONING AMPLIFIER RESISTANCE
Tester connectionConditionSpecified condition
A37-21 (TPBPa) - C25-3 (PT)AlwaysBelow 1 ohms
A37-18 (S5-3) - C25-1 (VZ)AlwaysBelow 1 ohms
A37-19 (SG) - C25-2 (GND)AlwaysBelow 1 ohms
C25-3 (PT) - Body groundAlways10 kohms or higher
C25-1 (VZ) - Body groundAlways10 kohms or higher
C25-2 (GND) - Body groundAlways10 kohms or higher

Fig. 110: Checking Harness And Connector (Cool Air Bypass 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
The air inlet servomotor is controlled by the A/C amplifier and moves the air inlet servomotor to the desired
position.
Fig. 111: DTC Detection Item Trouble Area Chart

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
WIRING DIAGRAM

Fig. 112: Air Inlet Damper Control Servomotor Circuit
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.PERFORM ACTUATOR CHECK

a. Remove the glove box to see and check the air inlet servomotor operation.
b. Set the actuator check mode (SEE ACTUATOR CHECK
).
c. Press the DEF switch to set the STEP operation.
d. Press the DEF switch in order and check the operation of the air inlet servomotor.

Fig. 113: Checking Actuator
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
DISPLAY CODE - RECIRCULATION DAMPER POSITION
OK:
Recirculation damper changes in accordance with each display code.
Display codeRecirculation damper position
0FRESH
1FRESH
2RECIRCULATION / FRESH
3RECIRCULATION
4FRESH
5FRESH
6FRESH
7FRESH
8FRESH
9FRESH

Result:
ACTUATOR 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 INLET SERVOMOTOR
a. Remove the air inlet servomotor.
b. Connect the positive (+) lead from the battery to terminal 5 and negative (-) lead to terminal 4, then
check that the lever turns to the "FRESH" position smoothly.
c. Connect the positive (+) lead from the battery to terminal 4 and negative (-) lead to terminal 5, then
check that the lever turns to the "RECIRCULATION" position smoothly.
NGA
OK (Checking from the PROBLEM SYMPTOMS TABLE)B
OK (Checking from the DTC)C

Fig. 114: Inspecting Air Inlet Servomotor
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPLACE AIR INLET SERVOMOTOR
OK: Go to next step
3.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
A36-17 (AIR) - A41-4 (REC)AlwaysBelow 1 ohms
A36-16 (AIF) - A41-5 (FRS)AlwaysBelow 1 ohms
A36-17 (AIR) - Body groundAlways10 kohms or higher
A36-16 (AIF) - Body groundAlways10 kohms or higher

Fig. 115: Checking Harness And Connector (Air Inlet Servomotor - Air Conditioning Amplifier)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.