2007 Compass Patriot MK Factory Service Manual 9 - ENGINE

P0850-PARK/NEUTRAL SWITCH PERFORMANCE

For a complete wiring diagram Refer to Section 8W.



Possible Causes
  
INTERMITTENT DTC
  
P/N SIGNAL CIRCUIT SHORTED TO VOLTAGE OR GROUND
  
DTCS PRESENT IN THE TRANSMISSION CONTROL MODULE (TCM)
  
POWERTRAIN CONTROL MODULE (PCM)
  

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - STANDARD PROCEDURE).



Diagnostic Test

1. DTC IS ACTIVE

Start the engine and allow it to reach normal operating temperature.

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.


NOTE: It may be necessary to test drive the vehicle in order to get this DTC to reset.


With the scan tool, select View DTCs.

Is the status Active for this DTC?

Yes


No

2. DTCS PRESENT IN THE TRANSMISSION CONTROL MODULE (TCM)

NOTE: 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 diagnostic procedure.


Turn the ignition on.
With the scan tool, select View DTCs in the TCM.

Are there any DTCs present in the TCM?

Yes


No

3. POWERTRAIN CONTROL MODULE (PCM)

Inspect the P/N signal circuit for a short to ground, or a short to voltage with the shifter in Drive or Reverse. Refer to the appropriate diagnostic procedures in the Transmission category.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Transmission Range Sensor, the TCM, and the PCM.
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals.
Refer to any Technical Service Bulletins that may apply.

Were any problems found?

Yes


No