2003 LEXUS LS430 Diagram AC

Fig. 199: Pattern Select Switch Circuit (PWR) - Wiring Diagram
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INSPECTION PROCEDURE
1.CHECK HARNESS AND CONNECTOR (PATTERN SELECT SWITCH ASSY NO. 1 - BODY
GROUND)
a. Disconnect the connector of pattern select switch.
b. Measure the resistance according to the value(s) in the table below.

Fig. 204: Identifying Passenger Side Junction Block Assy
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NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (See ELECTRONIC CIRCUIT
INSPECTION PROCEDURE )
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE
PATTERN SELECT SWITCH CIRCUIT (SNOW)
CIRCUIT DESCRIPTION
Passenger side J/B ECU receives pattern select switch information, and sends it through the multiplex
communication system and CAN system to the ECM.
ECT SNOW is the system that operates the throttle motor to control engine output to reduce skidding of the
driving wheels, guarantee takeoff acceleration, driving straightness and turning stability.
WIRING DIAGRAM

Fig. 205: Pattern Select Switch Circuit (SNOW) - Wiring Diagram
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INSPECTION PROCEDURE
1.DRIVING TEST
a. Start the engine.
b. Turn the ECT SNOW switch "OFF" (Normal drive mode).
c. Confirm vehicle response by driving from a parked position to fully depressing the accelerator
pedal.
d. Turn the ECT SNOW switch "ON" and perform the same check as (c).
Confirm that there is a difference between ECT SNOW switch "ON" and "OFF".
Driving test should be done on a paved road (a nonskid road).
Make sure not to use the TRAC system when testing a vehicle equipped with one.
OK:
There is a difference in acceleration between "ON" and "OFF".
NG: Go to step 2
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE
2.CHECK HARNESS AND CONNECTOR (PATTERN SELECT SWITCH ASSY NO. 1 - BODY
GROUND)

Fig. 1: Identifying Components Location Emission Control System
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SYSTEM DIAGRAM
Fig. 2: System Diagram Emission Control System (1 Of 4)

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Fig. 3: System Diagram Emission Control System (2 Of 4)
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Fig. 4: System Diagram Emission Control System (3 Of 4)
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Fig. 5: System Diagram Emission Control System (4 Of 4)
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ON-VEHICLE INSPECTION
1.INSPECT A/F COMPENSATION SYSTEM
a. Connect the hand-held tester to terminals E6-30 (OX1A) and E6-25 (O1A-) of the ECM.
b. Connect the hand-held tester to terminals E5-28 (OX2A) and E5-21 (02A-) of the ECM.

SYSTEM DIAGRAM
Engine control system is determined by the ECM based on signals from various sensors.
Fig. 2: Engine Control
- System Diagram
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