Volt

DTC P0776 or P0777

The clutch pressure control solenoid 2 is part of the control solenoid valve assembly and is not serviced separately. The clutch pressure control solenoid 2 controls transmission fluid pressure to the variable hi and 2-3-4 clutch regulator valve. The transmission control module monitors the transmission fluid pressure switch 3 state, in order to determine function of the clutch pressure control solenoid 2 and the variable hi and 2-3-4 clutch regulator valve. When the clutch pressure control solenoid 2 is commanded ON, the transmission fluid pressure switch 3 state should be High. When the clutch pressure control solenoid 2 is commanded Off, the transmission fluid pressure switch 3 parameter state should be Low.

P0776 or P0777

P0776

The clutch pressure control solenoid 2 commanded pressure is greater than 1800 kPa (261 psi) for up to 5 seconds depending on transmission temperature.

P0777

The clutch pressure control solenoid 2 commanded pressure is less than 5 kPa (1 psi) for up to 5 seconds depending on transmission temperature.

P0776 - Condition 1

The clutch pressure control solenoid 2 commanded pressure is 1800 kPa (261 psi) and the transmission fluid pressure switch 3 state is Low for 30 seconds.

P0776 - Condition 2

The clutch pressure control solenoid 2 commanded pressure is 1800 kPa (261 psi) and the transmission fluid pressure switch 3 state is Low for 2 seconds greater than 5 times during a key cycle.

P0777 - Condition 1

The clutch pressure control solenoid 2 commanded pressure is 5 kPa (1 psi) and the transmission fluid pressure switch 3 state is High for 36 seconds.

P0777 - Condition 2

The clutch pressure control solenoid 2 commanded pressure is 5 kPa (1 psi) and the transmission fluid pressure switch 3 state is High for 2 seconds greater than 5 times during a key cycle.

DTC P0776 is a type B and DTC P0777 is a Type A DTC.

When attempting to set transmission performance DTCs, observe the Freeze Frame and Failure Records to assist in duplicating the failure conditions. With a scan tool, monitor the pressure control solenoid valve 2 pressure command and the transmission fluid pressure switch 3 state parameters. Drive the vehicle to obtain two motor EV. The most likely cause of this DTC is an intermittent transmission pressure switch 3 -- verify transmission fluid pressure -- fault. Perform this operation 2 times. When the pressure control solenoid valve 2 pressure command is Yes, the transmission fluid pressure switch 3 state should be high. When the pressure control solenoid valve 2 pressure command is No, the transmission fluid pressure switch 3 state should be Low. The most likely cause of this DTC is an intermittent transmission pressure switch problem.

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Special Tools

DT-47825 Control Solenoid Test Plate

1. Verify that DTCs P0966, P0967, P0969, P0970, P0971, P0973, P0974, P0976, P0977, P2720, P2721, P2728, P2729, or P2730 are not set.

⇒	If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle .

2. Perform the Transmission Fluid Level and Condition Check .
3. Perform the Line Pressure Check .

⇒	If the pressure is out of specification, correct this first.

4. Perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection .

⇒	If cause for concern is found, repair or replace the Q8 control solenoid valve assembly.

5. Perform the Control Solenoid Valve and Transmission Control Module Assembly Solenoid Performance Test .

⇒	If the solenoid is found to be leaking or stuck closed, replace the Q8 control solenoid valve assembly.

6. Inspect the control valve body assembly for sticking valves, damage, scored bores, or debris. Refer to Control Valve Body Diagnostic Inspection .

⇒	If there is cause for concern in the valve body, repair or replace the valve body as necessary.

7. Inspect for P079B or P07A5 after repair.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.