P0797 — Pressure Control Solenoid C Stuck On
P0797 is the standardized powertrain DTC for “Pressure Control Solenoid C Stuck On.” The code identifies the monitored condition; it does not by itself prove which part failed.
What P0797 means
P0797 is the standardized powertrain DTC for “Pressure Control Solenoid C Stuck On.” The code identifies the monitored condition; it does not by itself prove which part failed.
How to interpret the code wording
“Stuck On” means the monitored function appears active when the module expects it to be released or off. Compare command and feedback, then test the actuator/solenoid, wiring, hydraulic/pneumatic path, and mechanical sticking as applicable.
Possible symptoms
- Harsh, delayed, or missing shifts
- Limp mode
- Transmission warning
- Possible slipping or flare
Causes to test
These are diagnostic possibilities, not a statistical parts-replacement ranking. Vehicle-specific service information takes priority.
- Solenoid electrical fault
- Valve-body sticking or hydraulic contamination
- Harness/connector issue
- Low/incorrect fluid or pressure problem
- TCM driver/control issue
Step-by-step diagnostic workflow
- Retrieve all TCM codes and freeze-frame data.
- Check transmission fluid level/condition with the correct temperature/procedure.
- Test solenoid circuit integrity and connector condition using OEM specifications.
- Use bidirectional control/pressure data when supported.
- Distinguish an electrical code from a hydraulic performance/stuck code before replacing parts.
- Clear codes only after repair, then complete an appropriate drive cycle and verify the code and symptoms do not return.
Scan data worth checking
- Solenoid command/duty
- Commanded gear
- Input/output speed
- Transmission fluid temperature
- Line/pressure-control data
Severity and drivability
Moderate to high. Solenoid/control faults can cause limp mode, harsh shifts, slipping, or excess heat.
Stop driving and investigate immediately if there is a flashing MIL, oil-pressure warning, overheating, fuel leakage, severe misfire, major loss of power, abnormal mechanical noise, or a transmission that is slipping badly.
Common diagnostic mistakes
- Replacing a solenoid for a hydraulic performance code without valve-body diagnosis
- Ignoring connector fluid intrusion or harness damage
- Clearing TCM adaptations without following relearn procedures
Related generic codes
Source and accuracy notes
Generic DTC structure and standardized definitions are governed by SAE J2012/J2012DA. Actual enable criteria, thresholds, circuit pinouts, test values, software conditions, and repair procedures vary by vehicle. Use current OEM service information for the exact year/engine/calibration and check applicable manufacturer technical service bulletins. See the site methodology and primary-reference policy.