LEXUS LS430 2003 Factory Repair Manual

One of the following conditions is met: Condition (A), (B) and (C) Condition (A)
TYPICAL MALFUNCTION THRESHOLDS TABLE - P0705
Condition (B)
When shift lever is in S position, one of the following conditions is met
TYPICAL MALFUNCTION THRESHOLDS TABLE - CONDITION B
Condition (C)
All of following conditions are met
TYPICAL MALFUNCTION THRESHOLDS TABLE - CONDITION C
P0850:
TYPICAL MALFUNCTION THRESHOLDS TABLE - P0850
COMPONENT OPERATING RANGE
P0705:
COMPONENT OPERATING RANGE TABLE - P0705
P0850:
Number of the following signal input at the same
time
2 or more
P switchON
N switchON
R switchON
D switchON
P switchON
N switchON
R switchON
P switchOFF
N switchOFF
R switchOFF
D switchOFF
NSW switchON
Park/neutral position switchThe park/neutral position switch sends only one
signal to the ECM.

COMPONENT OPERATING RANGE TABLE - P0850
WIRING DIAGRAM
Park/neutral position switchThe park/neutral position switch is OFF when
vehicle speed is 70 km/h or more and engine speed
is between 1,000 rpm or more and 2,500 rpm or
less.

Fig. 50: DTCs P0705, P0850 - Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
HINT:

According to the DATA LIST displayed by the hand-held tester, you can read the value of the switch, sensor,
actuator and so on without parts removal. Reading the DATA LIST as the first step of troubleshooting is one
method to shorten labor time.
a. Turn the ignition switch off.
b. Connect the hand-held tester together with the CAN VIM (controller area network vehicle interface
module) to the DLC3.
c. Turn the ignition switch to the ON position.
d. Push the "ON" button of the OBD II scan tool or the hand-held tester.
e. Select the item "DIAGNOSIS/ENHANCED OBD II/DATA LIST".
f. According to the display on tester, read the "DATA LIST".
Fig. 51: Test Item Reference Chart

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
1.INSPECT PARK/NEUTRAL POSITION SWITCH ASSY
a. Disconnect the park/neutral position switch connector.
b. Measure resistance according to the value(s) in the table below when the shift lever is moved to
each position.

Fig. 52: Identifying Park/Neutral Position Switch Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Standard:

Fig. 53: Park/Neutral Position Switch Reference Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPLACE PARK/NEUTRAL POSITION SWITCH ASSY (See step 25 on
REPLACEMENT
)
OK: Go to next step
2.INSPECT TRANSMISSION CONTROL SWITCH
a. Connect the park/neutral position switch connector.
b. Disconnect the transmission control switch connector of shift lock control unit assy.
c. Measure resistance according to the value(s) in the table below when the shift lever is moved to
each position.

Fig. 54: Identifying Transmission Control Switch Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Standard:

Fig. 55: Transmission Control Switch Reference Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPLACE TRANSMISSION CONTROL SWITCH (See COMPONENTS
)
OK: Go to next step
3.CHECK HARNESS AND CONNECTOR (PARK/NEUTRAL POSITION SWITCH -ECM)
a. Connect the transmission control switch connector of shift lock control unit assy.
b. Turn the ignition switch to the ON position, and measure the voltage according to the value(s) in
the table below when the shift lever is moved to each position.

Fig. 56: Identifying ECM Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Standard:

Fig. 57: ECM Connector Terminals Reference Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (SeeELECTRONIC CIRCUIT
INSPECTION PROCEDURE )
OK: REPLACE ECM (See REPLACEMENT
)
DTC P0710, P0712, P0713: TRANSMISSION FLUID TEMPERATURE SENSOR "A" CIRCUIT
LOW/HIGH INPUT
CIRCUIT DESCRIPTION
The ATF (Automatic Transmission Fluid) temperature sensor converts the fluid temperature into a resistance
value which is input into the ECM.
The ECM applies a voltage to the temperature sensor through ECM terminal OIL.
The sensor resistance changes with the transmission fluid temperature. As the temperature becomes higher, the
sensor resistance decreases.
One terminal of the sensor is grounded so that the sensor resistance decreases and the voltage goes down as the
temperature becomes higher.
The ECM calculates the fluid temperature based on the volta
ge signal.