Automatic Transmission - 2MT70
DTC P0776 or P0777
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
DTC Descriptors
DTC P0776
- Pressure Control (PC) Solenoid 2 - Stuck OFF
DTC P0777
- Pressure Control (PC) Solenoid 2 - Stuck ON
Circuit/System Description
The shift solenoid (SS) 2 is part of the control solenoid (w/body and transmission control module (TCM) valve assembly and is not serviced separately. The control solenoid (w/body and TCM) valve assembly supplies 12 volts to SS 2 on the high side driver 2 circuit. The control solenoid (w/body and TCM) valve assembly controls the normally closed SS 2 on the SS 2 control circuit. The SS 2 controls the transmission fluid to the shift solenoid valve - mode B.
Conditions for Running the DTC
P0776 or P0777
* The engine run time is greater than 1 second.
* Shift solenoid (SS) valve 1 is not in a transition state.
* The transmission line pressure is greater than 350 kpa (54 psi) and not fluctuating by greater than 30 kpa (4 psi).
* Propulsion is active.
P0776
The clutch PC solenoid 2 commanded pressure is greater than 1800 kpa (261 psi) for 4.5 seconds.
P0777
The clutch PC solenoid 2 commanded pressure is less than 5 kpa (1 psi) for 4.5 seconds.
Conditions for Setting the DTC
P0776 - Fail Case 1
The clutch PC solenoid 2 commanded pressure is 1800 kpa (261 psi) and the TFP switch 2 state is Low for 30 seconds.
P0776 - Fail Case 2
The clutch PC solenoid 2 commanded pressure is 1800 kpa (261 psi) and the TFP switch 2 state is Low for 0.5 seconds greater than 5 times during a key cycle.
P0777 - Fail Case 1
The clutch PC solenoid 2 commanded pressure is 5 kpa (1 psi) and the TFP switch 2 state is High for 36 seconds.
P0777 - Fail Case 2
The clutch PC solenoid 2 commanded pressure is 5 kpa (1 psi) and the TFP switch 2 state is High for 200 milliseconds greater than 5 times during a key cycle.
Action Taken When the DTC Sets
* P0776 and P0777 are Type B DTCs.
* The TCM pulses the solenoid in an attempt to free it.
* The TCM commands maximum line pressure.
* The TCM freezes transmission adaptive functions.
Conditions for Clearing the DTC
P0776 and P0777 are Type B DTCs.
Diagnostic Aids
When attempting to set transmission performance DTCs, observe the Freeze Frame and Failure Records to assist in duplicating the failure conditions.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information.
Special Tools
DT-47825 - Control Solenoid Test Plate Kit
Circuit/System Verification
1. Verify that DTCs P0721, P0722, P0723, 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 (Diagnostic Trouble Code Descriptions).
2. Perform the Transmission Fluid Check (Transmission Fluid Check) to verify correct fluid level and condition. The transmission fluid level should be within the crosshatch band and the transmission fluid should be red or dark brown.
• If the transmission fluid is low or discolored, refer to Transmission Fluid Replacement (Removal and Replacement).
3. Engine idling at operating temperature. Attempt to clean or free up a potential sticking valve with the scan tool Service Cleaning Procedure. Refer to Control Solenoid Valve and Transmission Control Module Assembly Cleaning (Control Solenoid Valve and Transmission Control Module Assembly Cleaning) for further instructions.
4. Operate the vehicle in drive to obtain 72 km/h (45 mph), stop the vehicle, turn the ignition Off for at least 30 seconds. Perform this 2 times.
• If the DTC resets, go to Circuit/System Testing.
Circuit/System Testing
1. Perform the Line Pressure Check (Line Pressure Check) procedure.
• If the pressure is out of specification, correct this concern first.
2. Perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection (Control Solenoid Valve and Transmission Control Module Assembly Inspection).
• If a concern is found, repair or replace the control solenoid (w/body and TCM) valve assembly.
3. Perform the Control Solenoid Valve and Transmission Control Module Assembly Solenoid Performance Test (Control Solenoid Valve and Transmission Control Module Assembly Solenoid Performance Test).
• If the solenoid is found to be leaking or stuck closed, replace the control solenoid (w/body and TCM) valve assembly.
4. Inspect the control valve lower body assembly for sticking valves, damage, scored bores, or debris.
• If a concern is found in the valve body, repair or replace the valve body as necessary.
Component Testing
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Perform the Control Valve Lower Body and Upper Body Replacement (2MT70 - Automatic Transmission) for valve body repair or replacement.
* Control Module References (Programming and Relearning) for control solenoid (w/body and TCM) valve assembly replacement, setup, and programming.