P0850
P0850-PARK/NEUTRAL SWITCH PERFORMANCEFor a complete wiring diagram refer to: Electrical Diagrams
When Monitored
Continuously with the transmission in Park, Neutral, or Drive and NOT in Limp-in mode.
Set Condition
This code will set if the PCM detects an incorrect Park/Neutral switch state for a given mode of vehicle operation. One trip fault. Three good trips to turn off the MIL.
Possible Causes
- TCM COMMUNICATION
- PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.
Diagnostic Test
1. P/N & D/R NOT IN CORRECT POSITION
NOTE: Before continuing, ensure communication can be established with the TCM. If the scan tool is unable to communicate with the TCM or if there are related communication DTCs present refer to the Communication Category and perform the appropriate symptom.
Ignition on, engine not running.
With the scan tool, read DTCs.
Is the DTC active at this time?
Yes >> Go To 2
No >> Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
2. CHECKING TCM DTC(S)
Turn the ignition off.
With the scan tool, read TCM DTCs.
Is there any there Transmission DTC(s) present?
Yes >> Refer to the appropriate Transmission symptom in the Transmission category.
No >> Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary Replace and program the Powertrain Module in accordance with the Service Information.
Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test