The pressure control (PC) solenoid valve is located in the valve body. The PC solenoid valve controls transmission line pressure based on current flow through the windings. The transmission control module (TCM) determines desired line pressure based on throttle position and other inputs. The TCM then varies the duty cycle on the high side of the PC solenoid valve to control current flow to the solenoid. Current is controlled from about 0.02 amp for maximum line pressure to 1.1 amps for minimum line pressure. The TCM monitors the actual current to the solenoid.

The PC solenoid valve is enabled.

The PC solenoid duty cycle is outside the range of 0.5-95 percent for 4 seconds.

DTC P0961 is a type C DTC.

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference

Electrical Information Reference

Scan Tool Reference

Special Tools Required

Start and idle the engine. Using the scan tool, select PC Solenoid under the Transmission Output Controls. With the scan tool, command several values of solenoid reference current from 0.1-1.1 amps and observe the PC Sol. Actual Current and the PC Sol. Ref. Current. The PC Sol. Actual Current should not vary from the PC Sol. Ref. Current by greater than 0.16 amp.

1. Disconnect the automatic transmission inline 20-way connector. Install the J 44152 jumper harness (20 pins) on the transmission side on the connector. Using the J 35616 GM terminal test kit, measure the resistance between the PC solenoid high control circuit and the PC solenoid low control circuit. The resistance should be between 3-7 ohms.

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If the resistance is greater than 7 ohms, test the PC Solenoid high control circuit or the PC solenoid low control circuit for an open or a faulty PC solenoid valve. If the resistance is less than 3 ohms, test for the PC solenoid high control circuit and the PC solenoid low control circuit shorted together of a faulty PC solenoid valve.

2. Measure the resistance between the PC solenoid high control circuit and the transmission case. Measure the resistance between the PC solenoid low control circuit and the transmission case. The resistance should be greater than 10K ohms.

⇒	If the resistance is less than 10K ohms, replace the automatic transmission wiring harness assembly.

3. Measure the resistance between the PC solenoid high control circuit and all other circuits of the J 44152 jumper harness (20 pins), except the PC solenoid low control circuit. Measure the resistance between the PC solenoid low control circuit and all other circuits of the J 44152 jumper harness (20 pins), except the PC solenoid high control circuit. The resistance should be greater than 10K ohms.

⇒	If the resistance is less than 10K ohms, replace the automatic transmission wiring harness assembly.

4. Remove the J 44152 jumper harness (20 pins) from the transmission side and install the J 44152 jumper harness (20 pins) on the engine side of the harness. Disconnect the TCM connector. Using the J 35616 GM terminal test kit, measure the resistance of the PC solenoid high control circuit between the TCM connector and the automatic transmission inline 20-way connector. Measure the resistance of the PC solenoid low control circuit between the TCM connector and the automatic transmission inline 20-way connector. The resistance should be less than 10 ohms for each circuit.

⇒	If the value is greater than 10 ohms repair the open in the affected circuit.

5. Measure the resistance between the PC solenoid high control circuit and ground. Measure the resistance between the PC solenoid low control circuit and ground. The resistance for each circuit should be greater than 10K ohms.

⇒	If the value is less than 10K ohms repair the short to ground in the affected circuit.

6. Connect the TCM connector. Turn ON the ignition, with the engine OFF. Test the PC solenoid high control circuit and the PC solenoid low control circuit for a short to voltage.

⇒	If a short to voltage condition is found, repair as necessary.

7. If all circuits/connections test normal, test or replace the PC solenoid valve.

Verify the PC solenoid valve resistance is between 3-7 ohms.

Perform the Diagnostic Repair Verification after completing the repair.