DTC Advanced Diagnostics: P0850
DTC P0850:Neutral Position Sensor A/B Incorrect Voltage Correlation

General Description

Table A: Neutral position sensor output voltage
 
NSS1 voltage
NSS2 voltage
Neutral
2.7 - 3.0 V
1.35 - 1.5 V

Neutral position sensor A and neutral position sensor B are semiconductor type that output different voltage characteristics. Each neutral position sensor outputs a voltage which depends on the condition is shown in Table A. The powertrain control module (PCM) judges whether it is in neutral or not from the neutral position sensor output voltage, and uses the information for various controls and auto idle stop system control (if equipped). Neutral position sensor A is for judging the neutral, and neutral position sensor B compares their output voltage to each other for malfunction detection. When the voltage correlation of neutral position sensor A and neutral position sensor B is out of a specified range for a set time, the PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type
Execution
Continuous
Sequence
None
Duration
2.1 seconds or more
DTC Type
One drive cycle, MIL off

Enable Conditions
Condition
Minimum
Maximum
12 volt battery voltage [BATTERY]
10.0 V
–
Vehicle
ON mode
[ ]: HDS Parameter

Malfunction Threshold
The neutral position sensor correlation allowed voltage in the Table B is specified value or more for at least 2.1 seconds.

Table B: The neutral position sensor A voltage and the neutral position sensor B voltage correlation
Neutral position sensor A output voltage
0.92 V or less
1.06 V
3.49 V
Sensor correlation allowed voltage
0.20 V
0.43 V
0.87 V

The neutral position sensor correlation allowed voltage calculate expression: Neutral position sensor A voltage/2 - Neutral position sensor B voltage

Possible Cause
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
Neutral position sensor A NSS1 line short to neutral position sensor B NSS2 line
Neutral position sensor A failure
Neutral position sensor B failure
PCM internal circuit failure

Confirmation Procedure
Operating Condition
1.
Turn the vehicle to the ON mode.
2.
Shift the transmission to all driving position/mode, then move it to the neutral position/mode.
With the HDS
None.

Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, a Pending DTC, a Confirmed DTC, and the freeze data are stored in the PCM memory. The MIL does not come on.

Conditions for clearing the DTC
The Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command.