2003 LEXUS LS430 park

CIRCUIT DESCRIPTION
The park/neutral position switch detects the shift lever position and sends signals to the ECM.
Fig. 49: DTC Reference Chart

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
MONITOR DESCRIPTION
These DTCs indicate a problem with the park/neutral position switch and the wire harness in the park/neutral
position switch circuit.
The park/neutral position switch detects the shift lever position and sends signals to the ECM.
For security, the park/neutral position switch detects the shift lever position so that engine can be started only
when the vehicle is in P or N shift position.
When the park/neutral position switch sends more than one signal at a time from switch positions P, R, N or D,
the ECM interprets this as a fault in the switch. The ECM will turn on the MIL and store the DTC.
MONITOR STRATEGY
P0705:
MONITOR STRATEGY TABLE - P0705
Related DTCsP0705: Park/neutral position switch/Verify switch
input

P0850:
MONITOR STRATEGY TABLE - P0850
TYPICAL ENABLING CONDITIONS
P0705:
TYPICAL ENABLING CONDITIONS TABLE - P0705
P0850:
All of following conditions are met
TYPICAL ENABLING CONDITIONS TABLE - P0850
TYPICAL MALFUNCTION THRESHOLDS
P0705:
Required sensors/ComponentsPark/neutral position switch
Frequency of operationContinuous
DurationCondition (A) and (B) 2 sec. Condition (C) 60 sec.
MIL operation2 driving cycles
Sequence of operationNone
Related DTCsP0850: Park/neutral position switch/Verify switch
input
Required sensors/ComponentsPark/neutral position switch
Frequency of operationContinuous
Duration30 sec.
MIL operation2 driving cycle
Sequence of operationNone
The monitor will run whenever this DTC is not
present.See LIST OF DISABLE A MONITOR
Ignition switchON
Battery voltage10.5 V or more
The monitor will run whenever this DTC is not
present.See LIST OF DISABLE A MONITOR
Vehicle speed70 km/h (43.47 mph) or more
Engine speed1,000 rpm or more and 2,500 rpm or less
Intake air amount per revolution0.8 g/rev or more
Battery voltage8 V or more
Ignition switchON
StarterOFF

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.

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. 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.