P27CFPressure Control Solenoid R Control Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P27CF tells that the control line of solenoid R is held low, as if shorted to ground. On the Corvette dual-clutch transmission GM (23OBDG07, still present in 24OBDG07) monitors synchronizer actuation valve 4 while energized; the driver chip compares the sense pin with a threshold of roughly 1.7 V and, after 150 ms below it, reports a ground fault rated Type A. Ford's TR9070 list gives P27CF to a shorted switch on SPV4. A ground short bypasses the driver, so the valve can apply rods 3 and 4 towards A when no shift is wanted; the controller then usually locks the affected gears. Chafed insulation, a crushed harness clip or a coil shorted to its housing are typical finds.
- What you may notice
- MIL on
- Unwanted rod movement, gears locked out
- Limp mode
- Likely causes
- LikelyChafed insulation grounding the control line
- PossibleHarness crushed at a clip or bracket
- RareSolenoid R coil shorted to its housing
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €100 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.