Diagnostic Instructions
DTC Descriptors
DTC P0776: Clutch Pressure Control (PC) Solenoid 2 - Stuck Off
DTC P0777: Clutch Pressure Control (PC) Solenoid 2 - Stuck On
Circuit/System Description
The clutch pressure control (PC) solenoid 2 is part of the control solenoid (w/body and TCM) valve assembly and is not serviced separately. The clutch PC solenoid 2 flows fluid to the 3-5-R clutch when commanded OFF and exhausts fluid when
commanded ON. The clutch PC solenoid 2 regulates the transmission fluid pressure to the 3-5-R clutch. The TCM calculates gear ratio based on data from the automatic transmission input speed sensor (ISS) and the output speed sensor (OSS).
The TCM compares the known transmission gear ratio to a calculated gear ratio for each commanded gear.
Conditions for Running the DTC
| • | No DTCs P0716 or P0717. |
| • | No DTCs P0722 or P0723. |
| • | No DTCs P1825 or P1915. |
P0776
| • | The transmission input shaft speed is greater than 60 RPM. |
| • | 3-5-R clutch is commanded ON. |
P0777
| • | The transmission output shaft speed is greater than 200 RPM. |
| • | 3-5-R clutch is commanded OFF. |
Conditions for Setting the DTC
P0776
The TCM detects an incorrect on-coming clutch gear ratio, or flare, when the 3-5-R clutch is commanded ON for 0.5 seconds and the transmission input shaft speed is greater than 75 RPM from the anticipated input shaft speed.
P0777
The TCM detects an incorrect off-going clutch gear ratio, or tie-up, when the 3-5-R clutch is commanded OFF for 0.5 seconds and the transmission input shaft speed is greater than 40 RPM from the anticipated input shaft speed.
Action Taken When the DTC Sets
| • | The TCM commands maximum line pressure. |
| • | The TCM inhibits TCC. |
| • | The TCM freezes transmission adaptive functions. |
Conditions for Clearing the DIC/DTC
DTCs P0776 and P0777 are Type A DTCs.
Diagnostic Aids
| • | When attempting to set transmission performance DTCs, observe the Freeze Frame and Failure Records to assist in duplicating the failure conditions. |
| • | If diagnosing a P0776 DTC and you know the 3-5-R Clutch is not stuck ON, inspect for a sticking clutch select valve 2. |
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
DTC Type Reference
Electrical Information Reference
Scan Tool Reference
Special Tools Required
| • | DT-47825
Control Solenoid Test Plate |
Circuit/System Verification
- Perform the
Transmission Fluid Check
.
- Operate the vehicle in drive with the calculated throttle position greater than 15 percent to obtain 72 km/h (45 mph).
| ⇒ | If the DTC resets, go to Circuit/System Testing. |
Circuit/System Testing
- Perform the
Line Pressure Check
.
| ⇒ | If the pressure is out of specification, correct this concern first. |
- Perform the
Control Solenoid Valve and Transmission Control Module Assembly Cleaning
and retest the DTC as outlined in the Circuit/System Verification steps.
| ⇒ | If the DTC resets, continue on with testing. |
- Perform the
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. |
- 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 control solenoid (w/body and TCM) valve assembly. |
- Inspect the control valve upper body assembly for sticking valves, damage, scored bores, or debris.
| ⇒ | If a concern if found in the valve body, repair or replace the valve body as necessary. |
- Inspect the 3-5-R clutch assembly for damage.
| ⇒ | If a concern is found in the 3-5-R clutch assembly, repair or replace as necessary. |
Component Testing
PC Sol 2 Operation
Operating Conditions
| Normal Operation
| Stuck OFF
| Stuck ON
|
Steady State Gears 3, 5
| 3, 5
| Neutral
| 3, 5
|
Steady State Gears 1, 2, 4, 6
| 1, 2, 4, 6
| 1, 2, 4, 6
| 3, 5
|
Garage Shift
| Park/Neutral to Reverse/Drive
| Neutral
| 1 Drive Gear
|
Downshift from gears 4, 5, 6 to 3, 5
| 3, 5
| Neutral
| 3, 5
|
Upshift from gears 3, 5 to 4, 5, 6
| 4, 5, 6
| 4, 5, 6
| 3, 5
|
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
| • | Control solenoid (w/body and TCM) valve assembly replacement - refer to
Control Module References
for replacement, setup, and programming. |
