Circuit Description

NOTE: After confirming DTC P0850, use the hand-held tester to confirm the PNP switch signal from the CURRENT DATA.

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 the body ground via the starter relay, thus 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 does the voltage of the 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 correction and for idle speed control (estimated control), etc.

Detecting condition of the DTC is when the park/neutral position switch is ON (N position) and driving under the following conditions for 30 seconds or more (2 trip detection logic):

Vehicle speed is 25 mph (40 km/h) or more.
Engine speed is 1500-4000 RPM.