P0973
DTC P0973 or P0974
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (with HP2) (Initial Inspection and Diagnostic Overview)Diagnostic System Check - Vehicle (without HP2) (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
DTC Descriptor
DTC P0973
- Shift Solenoid (SS) 1 Control Circuit Low Voltage
DTC P0974
- Shift Solenoid (SS) 1 Control Circuit High Voltage
Diagnostic Fault Information
Typical Scan Tool Data
Circuit/System Description
The shift solenoid (SS) 1 is part of the control solenoid (w/body and TCM) valve assembly and is not serviced separately. The control solenoid (w/body and TCM) valve assembly supplies 12 volts to SS 1 on the high side driver 1 circuit. The control solenoid (w/body and TCM) valve assembly controls the normally closed SS 1 on the SS 1 control circuit. The SS 1 controls the transmission fluid to the hybrid low, 1-2 clutch boost valve assembly.
In the OFF position, SS 1 controls the transmission fluid to the following components:
* EVT 1 mode, oil is supplied to drive motors with generator 1 and 2 for cooling and the hybrid low, 1-2 clutch
* EVT 2 mode, oil is supplied to drive motors with generator 1 and 2 for cooling and the hybrid direct 2-3-4 clutch
In the ON position, SS 1 controls the transmission fluid to the following components:
* Gear 1, oil is supplied to the hybrid low, 1-2 clutch and the 1-3 clutch
* Gear 2, oil is supplied to the hybrid low, 1-2 clutch and the hybrid direct 2-3-4 clutch
* Gear 3, oil is supplied to the hybrid direct 2-3-4 clutch and the 1-3 clutch
* Gear 4, oil is supplied to the hybrid direct 2-3-4 clutch and the 4th clutch
Conditions for Running the DTC
* The engine run time is greater than 5 seconds.
* The vehicle speed is less than 200 km/h (124 mph) for 5 seconds.
* The system voltage is 11-18 volts.
Conditions for Setting the DTC
P0973
The control solenoid (w/body and TCM) valve assembly detects an internal low voltage electrical malfunction of the SS 1 control circuit when SS 1 is commanded OFF for 1 second.
P0974
The control solenoid (w/body and TCM) valve assembly detects an internal high voltage electrical malfunction of the SS 1 control circuit when SS 1 is commanded ON for 1 second.
Action Taken When the DTC Sets
* DTCs P0973 and P0974 are Type A DTCs.
* The TCM defaults the transmission to EVT 1 or EVT 2 depending on vehicle speed.
* The TCM commands maximum line pressure.
* The TCM freezes transmission adaptive functions.
Conditions for Clearing the DTC
DTCs P0973 and P0974 are Type A DTCs.
Diagnostic Aids
When attempting to set solenoid electrical DTCs, ensure the control solenoid (w/body and TCM) valve assembly is warmed up and the transmission is operated long enough to ensure a 3°C (5°F) increase in TCM temperature. This will place the TCM under the optimal conditions to test solenoid electrical DTCs.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information.
Circuit/System Testing
1. Ensure the transmission fluid temperature is between 50 and 80°C (122 and 176°F).
2. Operate the vehicle in M 1 long enough to ensure at least a 3°C (5°F) rise in TCM temperature.
3. Place the gear selector in D for 5 seconds and then idle vehicle for 5 seconds.
4. Observe the scan tool data parameter Shift Sol. 1 CKT Status. The parameter should display OK.
• If the parameter displays Open, Short to Volts, Short to GND, or if the DTC resets, perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection (Control Solenoid Valve and TCM Assembly Solenoid Performance Test).
• If no concerns are found during the inspection, replace the control solenoid (w/body and TCM) valve assembly.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
Control Module References (Programming and Relearning) for control solenoid (w/body and TCM) valve assembly replacement, setup, and programming.