P0973
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 Valve 1 Control Circuit Low Voltage
DTC P0974
- Shift Solenoid Valve 1 Control Circuit High Voltage
Diagnostic Fault Information
Typical Scan Tool Data
Circuit/System Description
The shift solenoid (SS) valve 1 is part of the control solenoid valve assembly which has no serviceable components. SS valve 1 is a normally closed (NC) ON/OFF solenoid and is controlled by the transmission control module (TCM) through a low side driver. When the SS valve 1 is energized (ON), SS 1 fluid pressure is directed to the clutch select valve. Power to the SS 1 is supplied by the TCM 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
* The engine speed is 400 RPM or greater for 5 seconds.
* The ignition voltage is 9.0 volts or greater.
Conditions for Setting the DTC
P0973
The control solenoid valve assembly detects an internal low voltage electrical malfunction of the SS Valve 1 control circuit for 2 seconds.
P0974
The control solenoid valve assembly detects an internal high voltage electrical malfunction of the SS Valve 1 control circuit for 2 seconds.
Action Taken When the DTC Sets
P0973
* DTC P0973 is a Type A DTC.
* The TCM freezes transmission adaptive functions.
* The TCM commands maximum line pressure.
* The TCM limits the transmission to 2nd gear and reverse.
* The TCM inhibits the Tap Up/Tap Down 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 Sunshade - Left (D6I)
* Inline Harness Connector End Views X100
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-48616-10 - Adapter Harness
For equivalent regional tools, refer to Special Tools 6T30/6T40/6T45/6T50 - Automatic Transmission.
Circuit/System Verification
1. Operate the vehicle in 2nd gear long enough to ensure at least a 3°C (5°F) rise in TCM temperature.
2. Place the gear selector in Reverse for 5 seconds and then idle vehicle for 5 seconds. Verify with a scan tool, the following test status parameters displays OK.
* Shift Solenoid Valve 1 Control Circuit Open Test Status
* Shift Solenoid Valve 1 Control Circuit High Voltage Test Status
* Shift Solenoid Valve 1 Control Circuit Low Voltage Test Status
3. 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, remove the Q8 control solenoid valve assembly. Refer to Control Solenoid Valve and Transmission Control Module Assembly Replacement Service and Repair.
2. Perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection Control Solenoid Valve and Transmission Control Module Assembly Inspection.
3. Place the Q8 control solenoid valve assembly on a clean work surface near the transmission assembly.
4. Connect DT-48616-10 - harness between the vehicle wire harness X1 14-way transmission electrical connector, and the Q8 control solenoid valve assembly.
5. Ignition ON, verify with a scan tool the following test status parameters display, OK.
* Shift Solenoid Valve 1 Control Circuit Open Test Status
* Shift Solenoid Valve 1 Control Circuit High Voltage Test Status
* Shift Solenoid Valve 1 Control Circuit Low Voltage Test Status
• If any test status parameter displays Fault or Malfunction, replace the Q8 control solenoid valve assembly.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
Note: Before replacing the TCM, perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection Control Solenoid Valve and Transmission Control Module Assembly Inspection.
* Refer to Control Module References Control Module References for control solenoid valve assembly replacement, setup, and programming.
* Perform the Transmission Adaptive Values Learn Programming and Relearning following all transmission related repairs.