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P0851




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 Switch Circuit

DTC P0851
- Park/Neutral Position Switch Circuit Low Voltage

DTC P0852
- Park/Neutral Position 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 park/neutral signal circuit uses the TCM as a pass-through connector only. The TCM provides the low reference circuit to the PNP switch.

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 1000 RPM.

Conditions for Setting the DTC

P0850 and P0851

* ECM detects the Park/Neutral switch signal equals 0 volts (Park/Neutral) when the IMS reports a Drive range.

* 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.

* Above conditions must be met for.2 seconds.

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 Fuel Pump and Level Sensor Assembly

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-48616-10 - Adapter Harness

For equivalent regional tools, refer to Special Tools 6T30/6T40/6T45/6T50 - Automatic Transmission.

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. 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 14-way harness connector at the transmission.

2. Install the DT-48616-10 - harness to the vehicle wire harness X1 14-way transmission connector.

3. Ignition ON.

4. Test for 11 volts or greater between the adapter harness terminal 3 and ground.

• If less than 11 volts

1. Ignition OFF, remove the harness connector at the K20 engine control module.

2. Test for infinite resistance between the Park/Neutral signal circuit adapter harness terminal 3 and ground.

• If less than infinite resistance, repair the short to ground in the circuit.

• If infinite resistance.

3. Test for less than 2 ohms in the signal circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the signal circuit wire.

• If less than 2 ohms, replace the K20 engine control module.

• If 11 volts or greater

5. Ignition OFF, disconnect the DT-48616-10 - harness from the vehicle wire harness X1 14-way transmission connector.

6. Remove the transmission control valve body cover. Refer to Control Valve Body Cover Replacement Control Valve Body Cover Replacement.

7. Connect the vehicle wire harness X1 14-way transmission connector to the Q8 control solenoid valve assembly.

8. Disconnect the B15 transmission internal mode switch electrical X2 connector from the Q8 control solenoid valve assembly.

9. Ignition ON.

10. Verify the scan tool ECM Park/Neutral Position Switch parameter displays In Gear.

• If the parameter does not display In Gear

1. Ignition OFF, remove the harness connector at the K20 engine control module.

2. Test for infinite resistance between the Park/Neutral signal circuit terminal 3 and ground.

• If less than infinite resistance, repair the short to ground in the circuit.

• If infinite resistance, replace the K20 engine control module.

• If the 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. Ignition OFF, connect a 3A fused jumper wire between the X2 connector terminal A and ground, ignition ON.

14. Verify with a scan tool the ECM Park/Neutral Position Switch parameter displays Park/Neutral.

• If parameter does not display Park/Neutral

1. Ignition OFF, disconnect the harness connector at the K20 engine control module.

2. Test for less than 2 ohms in the Park/Neutral signal circuit wire, end to end.

• If 2 ohms or greater, repair the open/high resistance in the signal circuit wire.

• If less than 2 ohms, replace the K20 engine control module.

• If parameter displays Park/Neutral

15. Connect a 3-amp fused jumper wire between each transmission range signal circuit terminal listed below and the IMS ground circuit, terminal F on the TCM assembly. The corresponding scan tool TCM IMS A/B/C/P parameter should display LOW when the terminal is connected to the IMS ground.

* Switch Signal A: terminal B to ground circuit terminal F

* Switch Signal B: terminal C to ground circuit terminal F

* Switch Signal C: terminal D to ground circuit terminal F

* Switch Signal P: terminal E to ground circuit terminal F

• If the IMS parameter does not display the correct values
Replace the Q8 control solenoid valve assembly.

• If the IMS parameter displays the correct values

16. Replace the B15 transmission internal mode switch.

Repair Instructions

Note:

* Perform the Transmission Adaptive Values Learn Programming and Relearning following all transmission related repairs.

* Before replacing the TCM, perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection (Gen 1 with 1.4L - LCU, 1.6L - LDE or LFJ, 1.8L - LUW) Control Solenoid Valve and Transmission Control Module Assembly Inspection (Gen 1 with 1.4L - LCU, 1.6L - LDE or LFJ, 1.8L - LUControl Solenoid Valve and Transmission Control Module Assembly Inspection (Gen 2 with 1.4L - LUV) Control Solenoid Valve and Transmission Control Module Assembly Inspection (Gen 2 with 1.4L - LUV).

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

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