Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptor
DTC P0850: Park/Neutral Position (PNP) Switch CircuitDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Park/Neutral Signal | P0850 | P0850 | P0850 | -- |
Typical Scan Tool Data
Circuit | Normal Range | Short to Ground | Open/High Resistance | Short to Voltage |
|---|---|---|---|---|
Operating Conditions: Engine running, normal operating temperature, range selector in Park. Parameter Normal Range: 12 V = In-Gear, 0 V = Park/Neutral | ||||
Park/Neutral Signal | Park/Neutral | Park/Neutral | In-Gear | In-Gear |
Circuit/System Description
The transmission control module (TCM) provides the engine control module (ECM) shift position information through the high-speed communication on the controller area network (CAN). The automatic transmission shift position switch function is installed as one part of TCM. The shift range is calculated by TCM reading output voltage from gear lever position sensor installed TCM itself. The TCM and ECM use the decoded information for engine controls, starter enable, as well as determining the transmission shift pattern.
Conditions for Running the DTC
| • | The ignition voltage is between 10.2 V and 15.5 V. |
| • | The transmission is not in emergency mode. |
| • | TCM communication is normal. |
| • | Engine torque is equal to or greater than 75 N·m (55 lb ft). |
| • | Vehicle speed is equal to or greater than 10 km/h (6 MPH). |
Conditions for Setting the DTC
P0850
The ECM detects the park or neutral position signal when shift position reports a drive range.
Action Taken When the DTC Sets
| • | DTC P0850 is Type B DTC. |
| • | The ECM uses shift position switch range for engine start-up. |
Conditions for Clearing the DTC
DTC P0850 is Type B DTC.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
Electrical Information Reference
Description and Operation
Transmission Component and System Description
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- If there are any other engine or transmission communication related DTCs set, diagnose those DTCs first. Refer to Diagnostic Trouble Code (DTC) List - Vehicle.
- Ignition ON, observe the scan tool transmission range switch parameter in transmission data list while slowly moving the gear shift lever from Park and through all ranges. Verify the gear shift lever position matches the scan tool parameter.
- Ignition ON, observe the scan tool transmission range switch parameter while slowly moving the gear shift lever from Park and through all ranges. Verify the gear shift lever position matches the scan tool parameter.
- Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Note: It is especially important to closely observe the Park and Neutral to Drive transitional positions while moving the shift lever and observing for possible misalignment or slack in the shifter mechanism.
| ⇒ | If not within the specified value, refer to range selector lever cable adjustment Range Selector Lever Cable Adjustment and Transmission Adaptive Functions. |
| ⇒ | If not within the specified value, replace the K71 Transmission Control Module (TCM). |
| ⇒ | If the DTC resets, replace the K20 Engine Control Module (ECM). |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | TCM, refer to Control Module References for replacement, setup and programming. |
| ⇒ | Perform the Transmission Adaptive Functions. |
| • | ECM replacement, refer to Engine Control Module Replacement for LDK, Engine Control Module Replacement for LBS, LBX, LBY, Engine Control Module Replacement for LBW.. |
| • | ECM, refer to Engine Control Module Programming and Setup for setup and programming. |
