SAAB WIS ONLINE

DTC P0850-P0852

DTC P0850-P0852

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 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

Circuit Short to Ground Open/High Resistance Short to Voltage Signal Performance
Park/Neutral Signal P0850/P0851 P0850/P0852 P0850/P0852 -


Typical Scan Tool Data

PNP Switch

Circuit Short to Ground Open/High Resistance Short to Voltage
Operating conditions: Engine running, normal operating temperature Parameter Normal Range: 12 Volts = In-Gear, 0 Volts = Park/Neutral
Park/Neutral Signal Park/Neutral In-Gear In-Gear


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

• The ECM detects the park/neutral switch signal equals 0 volts when the IMS reports a Drive range for 0.2 second.

• The throttle position is 10 percent or greater.

• The engine torque is 75 Nm (55 lb ft) or higher.

• The vehicle speed is 10 km/h (6 mph) or greater.


P0852

The 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.

• The 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

Connector End View Reference


• Component Connector End Views

• Inline Harness Connector End Views


Description and Operation

Electronic Component Description

Electrical Information Reference


• Circuit Testing

• Connector Repairs

• Testing for Intermittent Conditions and Poor Connections

• Wiring Repairs


DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

DT-47825-20 Adapter Harness

For equivalent regional tools, refer to Special Tools .

Circuit/System Verification


1. If there are any other transmission DTCs set, diagnose those DTCs first. Refer to Diagnostic Trouble Code (DTC) List - Vehicle .

2. Perform the Range Selector Lever Cable Adjustment procedure to verify proper adjustment.

3. Ignition ON, observe the scan tool ECM PNP Switch parameter while moving the gear shift lever from Park and through all ranges. The parameter should display Park/Neutral when in Park or Neutral and In-Gear when in Reverse or Drive.

4. Observe the scan tool TCM IMS A/B/C/P parameter while slowly moving the gear shift lever from Park through all ranges. The parameter should match each gear range that is selected. Refer to Transmission Internal Mode Switch Logic .

5. After you complete the steps described above, check the diagnostic trouble code is not reset by driving the vehicle according to the conditions for running diagnostic trouble codes (DTC). You can also drive the vehicle according to the conditions you see in Freeze Frame/ Failure records. If the vehicle passes the circuit/system verification procedure, then stop. Do not perform the circuit/system test or component test as this may result in unnecessary part replacement. Refer to Testing for Intermittent Conditions and Poor Connections .


Circuit/System Testing


1.
Note

You must perform the Circuit/System Verification first.


Ignition OFF, disconnect the X1 20-way harness connector at the transmission.

2. Connect the DT-47825-20 harness to the vehicle wire harness X1 20-way transmission connector.

3. Test for less than 10 ohms between the ground circuit terminal 18 at the DT-47825-20 harness and ground.

4. If greater than the specified range, test the ground circuit for an open/high resistance.

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 .

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, verify the scan tool ECM PNP Switch parameter displays In Gear.

10. If not the specified value, test the P/N signal circuit for a short to ground. If the circuit tests normal, replace K20 Engine Control Module.

11. Verify the scan tool IMS A/B/C/P parameter displays HI for all 4 signal circuits.

12. If not the specified value, replace the Q8 control solenoid valve assembly. Refer to Control Solenoid Valve and Transmission Control Module Assembly Replacement .

13. Connect a 3-amp fused jumper wire between P/N signal circuit terminal F X2 and ground circuit terminal A X2 on the Q8 control solenoid valve assembly. Verify the PNP Switch parameter changes to Park/Neutral.

14. If not the specified value, test the P/N signal circuit for an open/high resistance. If the circuit tests normal, replace K20 Engine Control Module.

15. 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 unit. 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 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

16. If not the specified value, replace the Q8 control solenoid valve assembly.

17. If all circuits test normal, replace the B15 transmission internal mode switch.


Repair Instructions

Note
• Perform the Resetting of the transmission's adaption after all transmission repairs.

• Before replacing the TCM, perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection .


Perform the Diagnostic Repair Verification after completing the diagnostic procedure.


• Control Module References for ECM or control solenoid valve assembly replacement, setup, and programming

• Range Selector Lever Cable Adjustment

• Control Valve Body Cover Replacement

• Manual Shift Detent Lever with Shaft Position Switch Assembly Replacement