P0771
DTC P0771, P0985, or P0986
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 Descriptor
DTC P0771
- Shift Solenoid E Performance (Shift Solenoid Valve SR)
DTC P0985
- Shift Solenoid E Control Circuit Low (Shift Solenoid Valve SR)
DTC P0986
- Shift Solenoid E Control Circuit High (Shift Solenoid Valve SR)
Diagnostic Fault Information
Circuit/System Description
The powertrain control module (PCM) provides a B+ control circuit to the shift solenoid valve SR2. The ground circuit is provided through the body of the shift solenoid. The PCM uses signals from both vehicle speed sensors to detect the actual gear position, 1st, 2nd, 3rd, 4th or 5th gear. The PCM then compares the actual gear with the shift schedule stored in the PCM memory to detect electrical concerns with the PCM, shift solenoid, electrical circuits or with mechanical components of the transmission. When the gear position commanded by the PCM and the actual gear positions are not the same, the PCM illuminates the MIL and stores the DTC.
Conditions for Running the DTC
The engine is running.
Conditions for Setting the DTC
P0771
The gear position commanded by the PCM and the actual gear position are not the same.
P0985
The PCM detects a short to ground in the control circuit of the shift solenoid valve SR.
P0986
The PCM detects an open/high resistance in the control circuit of the shift solenoid valve SR.
Action Taken When the DTC Sets
DTC P0771, P0985, and P0986 are type A DTCs.
Conditions for Clearing the DTC
DTC P0771, P0985, and P0986 are type A DTCs.
Diagnostic Aids
* The battery must be fully charged. Refer to Battery Inspection/Test (Battery Inspection/Test).
* All resistance tests are conducted with the component at 20°C (68°F).
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics (Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
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 (Programming and Relearning) for scan tool information.
Circuit/System Verification
Note: If other DTCs are set, diagnosis them first. Refer to Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle).
1. Operate the vehicle at less than 48 km/h (30 mph) with steady throttle input.
2. Command the transmission to shift up or shift down with a scan tool. The transmission should shift to the gear commanded by the scan tool.
3. 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.
Circuit/System Testing
1. Ignition OFF, disconnect the transmission X2 harness connector.
2. Test for 11-15 ohm between the transmission component connector X2 terminal 9 and ground.
• If not within the specified value, test the internal transmission circuits for a short to ground or an open/high resistance. If the circuit tests normal, replace the shift solenoid valve SR.
3. Ignition OFF, connect the transmission X2 harness connector.
4. Disconnect the PCM X2 harness connector.
5. Test for 11-15 ohm between the PCM harness connector X2 terminal 60 and ground.
• If not within the specified value, test the voltage circuit for a short to ground or an open/high resistance. If the circuits tests normal, replace the PCM.
6. If all circuits test normal, refer to Symptoms - Automatic Transmission (Symptoms - Automatic Transmission).
Component Testing
1. Ignition OFF, remove the shift solenoid valve SR.
2. Connect a 10 A fused jumper wire to the terminal of the shift solenoid valve SR and B+.
3. Connect a second jumper wire to the body of the shift solenoid valve SR.
4. Momentary connect the other end of the second jumper wire to B-. The solenoid should energize and click.
• If the solenoid does not energize and click, replace the shift solenoid valve SR.
5. If all circuits test normal, refer to Symptoms - Automatic Transmission (Symptoms - Automatic Transmission).
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Control Valve Body Replacement (MVD 5 Speed - Automatic Transmission)
* Powertrain Control Module Replacement (Service and Repair)
* Powertrain Control Module Programming and Setup (Testing and Inspection)