The 1-2 shift solenoid (SS) valve controls the fluid flow acting on the 1-2 and 3-4 shift valves. The solenoid is a normally-open exhaust valve. With the 2-3 SS valve, the 1-2 SS valve allows 4 different shifting combinations. The solenoid attaches to the control valve body within the transmission. The 1-2 SS valve receives ignition voltage through the ignition voltage circuit. The transmission control module (TCM) controls the solenoid by providing the ground path on the 1-2 SS valve control circuit.

P0973

Either one of the following conditions occurs for 4.3 seconds:

P0974

If the TCM commands the solenoid ON and the voltage feedback remains high B+.

P0973

P0974

DTCs P0973 and P0974 are Type B DTCs.

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Transmission General Information

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Transmission Control Module Scan Tool Information

Special Tools

1. Ignition ON, engine OFF, observe the 1-2 Sol. CKT Status parameter while commanding the 1-2 SS ON and OFF with a scan tool. The reading should display OK or Indeterminate.
2. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Important: Additional DTCs may set when disconnecting the automatic transmission inline 20-way connector.

1. Ignition OFF, disconnect the AT inline 20-way connector at the transmission.
2. Install the J 45681 jumper harness, on the engine side of the AT inline 20-way connector.
3. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal L and ground.

⇒	If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test all components connected to the ignition circuit and replace as necessary.

4. Connect a test lamp between the control circuit terminal A and the ignition circuit terminal L.
5. Command the 1-2 SS ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

⇒	If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the TCM.

⇒	If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the TCM.

6. If all circuits test normal, test the automatic transmission internal wiring harness and the 1-2 shift solenoid.

1. Ignition OFF, disconnect the AT inline 20-way connector at the transmission.
2. Install the J 44152 jumper harness (20 pins), on the transmission side of the AT inline 20-way connector.
3. Test for 19-31 ohms of resistance between the control terminal A and the ignition terminal L of the transmission.

⇒	If not within the specified range, test the circuits for a short to ground or an open/high resistance. If a circuit is shorted or open replace the internal transmission harness, if the circuits test normal, replace the 1-2 shift solenoid.

4. Test for infinite resistance between each terminal and the transmission housing/case.

⇒	If not the specified value, test the circuits for a short to ground or an open/high resistance. If a circuit is shorted replace the internal transmission harness, if the circuits test normal, replace the 1-2 shift solenoid.

Perform the Diagnostic Repair Verification after completing the repair.