P0850
DTC P0850-P0852
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptors
DTC P0850
-
Park/Neutral Position (PNP) Switch Circuit
DTC P0851
-
Park/Neutral Position (PNP) Switch Circuit Low Voltage
DTC P0852
-
Park/Neutral Position (PNP) Switch Circuit High Voltage
Diagnostic Fault Information
Typical Scan Tool Data
Circuit/System Description
The transmission manual shift shaft switch assembly, also known as the internal mode switch (IMS), is a sliding contact switch attached to the manual shift shaft inside the transmission case. The park/neutral position (PNP) switch is integrated into the IMS and connects to the transmission control module (TCM) lead-frame through a short wire harness. The circuit uses the TCM as a pass-through connector only. The park/neutral signal is sent from the park/neutral switch directly to the engine control module (ECM) and is used for engine start enable.
Conditions for Running the DTC
* Ignition voltage is between 8-18 volts.
* Engine speed is greater than 1,000 RPM.
Conditions for Setting the DTC
P0850 and P0851
* ECM detects the park/neutral switch signal equals 0 volts when the IMS reports a Drive range for 0.2 second.
* Throttle position is 10 percent or greater.
* Engine torque is 75 Nm (55 lb ft) or greater.
* Vehicle speed is 10 km/h (6 mph) or greater.
P0852
ECM detects the park/neutral switch signal equals 12 volts (in-gear) when the IMS reports a park/neutral range for 0.2 second.
Action Taken When the DTC Sets
* DTCs P0850, P0851, and P0852 are Type C DTCs.
* ECM uses IMS range for engine start-up.
Conditions for Clearing the DTC
DTCs P0850, P0851, and P0852 are Type C DTCs.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics Electrical Diagrams
Connector End View Reference
* Component Connector End Views A/C Compressor Clutch
* Inline Harness Connector End Views X101
Description and Operation
Electronic Component Description Electronic Component Description
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Control Module References for scan tool information
Special Tools
DT-47825-20 - Adapter Harness
For equivalent regional tools, refer to Special Tools Tools and Equipment.
Circuit/System Verification
1. If there are any other transmission DTCs set, diagnose those DTCs first. Refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.
2. Ignition ON.
3. Verify the gear shift lever position matches the scan tool TCM Internal Mode Switch parameter while slowly moving the gear shift lever from Park through all ranges.
• If the parameter is not correct for each lever position
Refer to Range Selector Lever Cable Adjustment Adjustments.
• If the parameter is correct for each lever position
4. Verify the scan tool ECM Park/Neutral Position Switch parameter displays Park/Neutral when in Park or Neutral and In-Gear when in Reverse or Drive.
• If the parameter is not correct for each lever position
Refer to Circuit/System Testing below.
• If the parameter is correct for each lever position
5. Verify the scan tool TCM IMS A/B/C/P parameter displays the correct values while moving the gear shift lever from Park through all ranges. Refer to Transmission Internal Mode Switch Logic Transmission Internal Mode Switch Logic.
• If the parameter is not correct for each lever position
Refer to Circuit/System Testing below.
• If the parameter is correct for each lever position
6. After performing the above steps, verify that the DTC does not reset by operating the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions you observe from the Freeze Frame/Failure Records data. If the vehicle passes the Circuit/System Verification procedure, then STOP. Do not perform the Circuit/System Testing or Component Testing as this may result in an unnecessary part replacement. Refer to Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections.
Circuit/System Testing
Note:
You must perform the Circuit/System Verification first.
1. Ignition OFF, disconnect the X1 20-way harness connector at the transmission.
2. Install the DT-47825-20 - harness to the vehicle wire harness X1 20-way transmission connector.
3. Ignition ON.
4. Test for less 11-13 ohms between the terminal 20 at the DT-47825-20 - harness and ground.
• If not between 11-13 volts
1. Ignition OFF.
2. Test the Park/Neutral signal circuit for a short to ground.
• If circuit has a short to ground, repair the wire.
• If circuit does not have a short to ground.
3. Test for less than 2 ohms in the Park/Neutral signal circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K20 engine control module.
• If between 11-13 volts
5. Disconnect the DT-47825-20 - harness from the vehicle wire harness X1 20-way transmission connector.
6. Remove the control valve body cover. Refer to Control Valve Body Cover Replacement Control Valve Body Cover Replacement.
7. Connect the vehicle wire harness X1 20-way transmission electrical connector to the Q8 control solenoid valve assembly.
8. Disconnect the B15 IMS connector X2 at the Q8 control solenoid valve assembly.
9. Ignition ON.
10. Verify the scan tool ECM Park/Neutral Position Switch parameter displays In Gear.
• If In Gear is not displayed
1. Ignition OFF.
2. Test the Park/Neutral signal circuit for a short to ground.
• If circuit has a short to ground, repair the wire.
• If circuit does not have a short to ground, replace the K20 engine control module.
• If parameter displays In Gear
11. Verify the scan tool TCM IMS A/B/C/P parameter displays High for all 4 signal circuits.
• If High is not displayed
Replace the Q8 control solenoid valve assembly.
• If High is displayed
12. Test for 11 volts or greater between terminal A on the X2 connector at the Q8 control solenoid valve assembly and ground at the transmission case.
• If less than 11 volts
Replace the Q8 control solenoid valve assembly.
• If 11 volts or greater
13. Connect a 3-amp fused jumper wire between park/neutral signal circuit terminal F X2 and ground circuit terminal A X2 on the Q8 control solenoid valve assembly. Verify the Park/Neutral Position Switch parameter changes from In Gear to Park/Neutral when the signal circuit is connected to ground.
• If parameter does not change from In Gear to Park/Neutral
1. Ignition OFF.
2. Test for less than 2 ohms in the Park/Neutral signal circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit
• If less than 2 ohms, replace the K20 engine control module
• If parameter changes from IN Gear to Park/Neutral
14. Connect a 3-amp fused jumper wire between each transmission range signal circuit terminal listed below and the IMS ground circuit, terminal A on the TCM assembly. Verify the scan tool TCM IMS A/B/C/P parameter displays Low when the terminal is connected to the IMS ground.
* Switch Signal A terminal E to ground circuit terminal A
* Switch Signal B terminal D to ground circuit terminal A
* Switch Signal C terminal C to ground circuit terminal A
* Switch Signal P terminal B to ground circuit terminal A
• If any parameter does not display the correct value
Replace the Q8 control solenoid valve assembly.
• If parameter displays the correct value
15. Replace the B15 transmission internal mode switch.
Repair Instructions
Note:
* Perform the Reset Transmission Adapts Reset Transmission Adapts following all transmission related repairs.
* Before replacing the TCM, perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection Control Solenoid Valve and Transmission Control Module Assembly Inspection.
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Control Module References Control Module References for ECM or control solenoid valve assembly replacement, setup, and programming
* Range Selector Lever Cable Adjustment Adjustments
* Control Valve Body Cover Replacement Control Valve Body Cover Replacement
* Manual Shift Detent Lever with Shaft Position Switch Assembly Replacement Service and Repair