P0797 code meaning
Pressure Control Solenoid C Stuck On
Powertrain system Generic code P07xx codes Check engine light
What P0797 means
Pressure control solenoids are current-controlled proportional valves, and what B and C mean depends on the design: on GM's clutch-to-clutch automatics they are the pressure valves of clutches 2 and 3, on GM's CVT B is primary pulley pressure and C line pressure, on Jatco CVTs B is the secondary pressure valve, on Saab's AF40 B and C are clutch valves SLC1/SLC2. P0797 means valve C is electrically fine but pressure stays applied – the off-going clutch does not release. GM's 9-speed flags clutch 3 slip below 50 rpm for 0.8 s (0.15 s in other cases), the 8-speed uses a torque and inertia phase test, both after one trip; GM's 9-speed bulletin and Maserati's MC20 dual-clutch sheet list the code too. Harsh shift jolts and a default gear follow.
P0797 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyHard
- Typical labor1 to 14 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0797
- Harsh shift jolt, transmission ties up
- Limp mode in a fixed gear
- Check engine light
Common causes of P0797
- Most likelySpool or pressure valve sticking
- PossibleClutch stuck or piston hanging
- PossibleContaminated fluid (debris after clutch damage)
- Less likelySoftware or false setting
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Pressure control solenoidTransmission valve bodyTransmission clutchesTransmission control module
What each part of P0797 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 7 | Area: transmission. |
| 97 | The exact fault in that area. |
What to do next
- Note P0797 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0797
What does P0797 mean?
P0797 means "Pressure Control Solenoid C Stuck On". Pressure control solenoids are current-controlled proportional valves, and what B and C mean depends on the design: on GM's clutch-to-clutch automatics they are the pressure valves of clutches 2 and 3, on GM's CVT B is primary pulley pressure and C line pressure, on Jatco CVTs B is the secondary pressure valve, on Saab's AF40 B and C are clutch valves SLC1/SLC2. It is a generic code, so it means the same on every make.
Is it safe to drive with P0797?
Drive gently and only to a workshop. With P0797 the car can go into limp mode (reduced power) to protect itself.
Will P0797 fail an emissions test?
Yes, it can. P0797 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0797 to fix?
Difficulty: hard. A typical repair takes 1 to 14 hours of work. This is a job for a workshop.
Will P0797 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.