P27C9 code meaning
Pressure Control Solenoid R Performance/Stuck Off
Powertrain system Generic code P27xx codes Check engine light
What P27C9 means
Solenoid R is the fourth synchronizer pressure valve on the dual-clutch units that use it, and P27C9 says it failed to move anything. GM's 2023 and 2024 Corvette tables (23OBDG07/24OBDG07) call it shift solenoid 4; it acts on the same two rods as valve 3 but drives them back from B towards A. The integrity check commands that motion for each selector position and expects more than 100 µm of rod travel; anything less marks valve 4 hydraulically stuck off, Type A. Ford's TR9070 table lists P27C9 for SPV4. As the opposite direction is affected, the gearbox may be unable to move those rods back, so certain gears can be neither selected nor released.
P27C9 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor2 to 8 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P27C9
- MIL on with transmission message
- Gear stays engaged or cannot be selected
- Reduced gear range
Common causes of P27C9
- Most likelySpool of solenoid R stuck closed
- PossibleSupply passage or screen to valve R clogged by debris
- PossibleLeaking actuator seal on the B-to-A side of rods 3/4
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Pressure control solenoid rValve body
What each part of P27C9 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 7 | Area: transmission. |
| C9 | The exact fault in that area. |
What to do next
- Note P27C9 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 P27C9
What does P27C9 mean?
P27C9 means "Pressure Control Solenoid R Performance/Stuck Off". Solenoid R is the fourth synchronizer pressure valve on the dual-clutch units that use it, and P27C9 says it failed to move anything. It is a generic code, so it means the same on every make.
Is it safe to drive with P27C9?
Drive gently and only to a workshop. With P27C9 the car can go into limp mode (reduced power) to protect itself.
Will P27C9 fail an emissions test?
Yes, it can. P27C9 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 P27C9 to fix?
Difficulty: workshop only. A typical repair takes 2 to 8 hours of work. This is a job for a workshop.
Will P27C9 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.