P0974
DTC P0973 or P0974
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 P0973
- Shift Solenoid 1 Control Circuit Low Voltage
DTC P0974
- Shift Solenoid 1 Control Circuit High Voltage
Diagnostic Fault Information
Typical Scan Tool Data
Circuit/System Description
The shift solenoid 1 is part of the control solenoid valve assembly which has no serviceable parts. The shift solenoid 1 is a normally closed (NC) ON/OFF solenoid and is controlled by the Transmission Control Module through a low side driver. When the shift solenoid 1 is energized (ON), shift solenoid 1 fluid pressure is directed to the clutch select valve 2. Power to the shift solenoid 1 is supplied by the Transmission Control Module through a high side driver (HSD). The HSD protects the circuit and components from excessive current flow. If excessive current flow is detected, the HSD will turn OFF. When the fault is corrected, the HSD will reset.
Conditions for Running the DTC
P0973 or P0974
* DTCs P0973 or P0974 is not set.
* The ignition voltage is between 8.6-32 V.
* The engine speed is between 400-7500 RPM for 5 seconds.
Conditions for Setting the DTC
P0973
The control solenoid valve assembly detects an internal low voltage electrical malfunction of the shift solenoid 1 control circuit when the shift solenoid 1 is commanded OFF for 2 seconds.
P0974
The control solenoid valve assembly detects an internal high voltage electrical malfunction of the shift solenoid 1 control circuit when the shift solenoid 1 is commanded ON for 2 seconds.
Action Taken When the DTC Sets
P0973
* DTC P0973 is a Type A DTC.
* The TCM defaults the transmission to 2nd gear or reverse gear.
* The TCM forces the torque converter clutch (TCC) OFF.
* The TCM commands maximum line pressure.
* The TCM freezes transmission adaptive functions.
* The TCM enables Torque Management.
* The TCM inhibits TAP function.
* The TCM inhibits manual shifting of forward gears.
P0974
* DTC P0974 is a Type B DTC.
* The TCM inhibits 1st gear.
Conditions for Clearing the DIC/DTC
* DTC P0973 is a Type A DTC.
* DTC P0974 is a Type B DTC.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics Electrical Diagrams
Connector End View Reference
* Component Connector End Views Connector End Views By Name
* Inline Harness Connector End Views X101
Description and Operation
* Transmission General Description Transmission General Description
* Transmission Component and System Description Transmission Component and System Description
* 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-47825-10 - Jumper Harness
For equivalent regional tools, refer to Special Tools Tools and Equipment.
Circuit/System Verification
1. Engine Running, place the gear selector in Reverse for 5 seconds and then idle the vehicle in Park for 5 seconds.
2. Verify the scan tool parameters display OK.
* Shift Solenoid Valve 1 Control Circuit High Voltage Test Status
* Shift Solenoid Valve 1 Control Circuit Open Test Status
* Shift Solenoid Valve 1 Control Circuit Low Voltage Test Status
• If Malfunction is displayed
Refer to Circuit/System Testing.
• If Malfunction is not displayed
3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observe from the Freeze Frame/Failure Records data.
4. Verify the DTC does not set.
• If the DTC sets
Refer to Circuit/System Testing.
• If the DTC does not set
5. All OK.
Circuit/System Testing
Note: You must perform the Circuit/System Verification first.
1. Ignition OFF, remove the Q8 Control Solenoid Valve Assembly. Refer to Control Solenoid Valve and Transmission Control Module Assembly Replacement Service and Repair.
2. Verify and inspect the Q8 Control Solenoid Valve Assembly. The Q8 Control Solenoid Valve Assembly must be externally cleaned of all debris and each solenoid resistance value must be within the specified range. Refer to Control Solenoid Valve and Transmission Control Module Assembly Inspection Control Solenoid Valve and Transmission Control Module Assembly Inspection.
• If the solenoid resistance is not within the specified ranges
Replace the Q8 Control Solenoid Valve Assembly.
• If the solenoid resistance is within the specified ranges
3. Place the Q8 Control Solenoid Valve Assembly on a clean work surface near the transmission assembly.
4. Connect DT-47825-10 - jumper harness between the vehicle wire harness electrical connector, and the Q8 Control Solenoid Valve Assembly electrical connector. Ignition ON.
5. Verify the scan tool parameters do not display Malfunction:
* Shift Solenoid Valve 1 Control Circuit High Voltage Test Status
* Shift Solenoid Valve 1 Control Circuit Open Test Status
* Shift Solenoid Valve 1 Control Circuit Low Voltage Test Status
• If Malfunction is displayed
Replace the Q8 Control Solenoid Valve Assembly.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Perform the Reset Transmission Adapts Reset Procedure 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.
* Control Module References Control Module References for control solenoid valve assembly replacement, programming, and setup.