For 1990-2009 cars

### 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 P0973: Shift Solenoid (SS) 1 Control Circuit Low Voltage
DTC P0974: Shift Solenoid (SS) 1 Control Circuit High Voltage

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage
--- | --- | --- | ---
Shift Solenoid (SS) 1 Control | P0973 | P0974 | P0974

### Typical Scan Tool Data

#### Shift Solenoid (SS) 1

Circuit | Short to Ground | Open/High Resistance | Short to Voltage
--- | --- | --- | ---
Operating Conditions: Engine running, normal operating temperature Parameter Normal Range: OK
Shift Sol. 1 CKT Status | Short to GND | Open | Short to Volts

### Circuit/System Description

The shift solenoid (SS) 1 is part of the control solenoid (w/body and TCM) valve assembly. The control solenoid (w/body and TCM) valve assembly has no seviceable parts. The TCM supplies 12 volts to SS 1 through the high side driver circuit. The HSD protects the circuits and components that the TCM powers. Should the circuit overload the driver will shutdown. After the overload is removed the HSD reset.

The TCM controls the shift solenoid 1 (SS 1) through the SS 1 control circuit. The SS 1 is a normally closed (NC), On/Off solenoid. When the TCM opens the SS 1 control circuit, (solenoid off), solenoid signal fluid exhausts and the Mode-2 valve moves to the non-apply position. In the OFF position no oil is supplied to the clutch pressure control (PC) solenoid 3 or the transmission fluid pressure (TFP) switch 5, and the 4-5-6 clutch is fed by drive fluid. In the ON position, Reverse fluid is allowed to flow and is supplied to the 3-5-R clutch.

### Conditions for Running the DTC

• | The engine run time is greater than 1.5 seconds.

• | The ignition voltage is between 9.0 volts and 19.0 volts.

#### P0973

DTC P0973 has not failed this ignition cycle.

#### P0974

DTC P0974 has not failed this ignition cycle.

### 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 the SS 1 is commanded OFF for 1.2 seconds or greater.

#### P0974

The control solenoid (w/body and TCM) valve assembly detects an internal high voltage electrical malfunction of the SS 1 control circuit when the SS 1 is commanded ON for 1.2 seconds or greater.

### 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 forces the torque converter clutch (TCC) OFF and inhibits.

• | The TCM inhibits torque converter clutch (TCC) engagement.

• | The TCM defaults the transmission to 2nd gear.

• | The TCM inhibits the Tap Up/Tap Down function.

• | The TCM inhibits torque management.

#### 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.

### Diagnostic Aids

#### P0973

DTC P0973 detects a continuous short to ground in the mode 2 on/off solenoid control circuit.

#### P0974

DTC P0974 detects a continuous open or short to voltage in the mode 2 on/off solenoid control circuit.

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 in 2nd gear 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

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

• | Transmission General Description

• | Transmission Component and System Description

• | 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

### Circuit/System Verification

1. Ensure the transmission fluid temperature is between 50-80°C (122-176°F).
2. Perform the Control Solenoid Valve and Transmission Control Module Assembly Cleaning procedure to dislodge debris and free up valves.
3. Operate the vehicle in 2nd gear long enough to ensure at least a 3°C (5°F) rise in TCM temperature.
4. Place the gear selector in Reverse for 5 seconds and then idle vehicle for 5 seconds.
5. Verify the scan tool data parameter Shift Sol. 1, displays OK.

⇒ | If not the specified value, replace the control solenoid (w/body and TCM) valve assembly.

6. 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.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

| Important: Before replacing the TCM, perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection .

• | Refer to Control Module References for control solenoid (w/body and TCM) valve assembly replacement, setup, and programming.

• | Perform the Service Fast Learn Adapts following all transmission related repairs.