P27C9Pressure Control Solenoid R Performance/Stuck Off
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- 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.
- What you may notice
- MIL on with transmission message
- Gear stays engaged or cannot be selected
- Reduced gear range
- Likely causes
- 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
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €300 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.