Toyota 1 MZ–FE Manual page 562

EG2–562
DTC P1780 Park Neutral Position Switch Malfunction
CIRCUIT DESCRIPTION
The park/neutral position switch goes on when the shift lever is in the N or P shift position. When it goes
on terminal NSW of the ECM is grounded to body ground via the starter relay thus the terminal NSW
voltage becomes 0 V, When the shift lever is in the D, 2, L or R position, the park/neutral position switch
goes off, so the voltage of ECM terminal NSW becomes battery voltage, the voltage of the ECM internal
power source.
If the shift lever is moved from the N position to the D position, this signal is used for air–fuel ratio correc-
tion and for idle speed control (estimated control), etc.
Diagnostic Trouble Code Detecting Condition
DTC No.
Two or more switches are ON simultaneously for
"N", "2" and "L" position.
(2 trip detection logic)
When driving under conditions a) and b) for 30 sec.
P1780
or more the park/neutral position switch is ON
( N position).
(2 trip detection logic)
a) Vehicle speed; 70 km/h (44 mph) or more
b) Engine speed; 1,500 – 2,500 rpm
HINT: After confirming DTC P1780 use the TOYOTA hand–held tester to confirm the PNP switch
signal from "CURRENT DATA".
1MZ–FE ENGINE – CIRCUIT INSPECTION
Short in park/neutral position switch circuit.
Park/neutral position switch.
ECM
Trouble Area