P27C4 code meaning
Pressure Control Solenoid P Intermittent
Powertrain system Generic code P27xx codes Check engine light
What P27C4 means
P27C4 indicates that solenoid P works most of the time but its circuit or response briefly drops out. No manufacturer documents the code publicly; GM's Corvette DCT table 23OBDG07 and Ford's TR9070 list, which both use this solenoid as synchronizer valve 3, only publish hard faults such as P27C5, P27C7, P27C8 and the hydraulic codes P27C1/P27C2. CARB 13 CCR 1968.2 counts transmission solenoids among monitored outputs. Intermittent dropouts usually come from fretting corrosion at terminals, a conductor broken inside its insulation, or a solenoid whose winding opens when it reaches operating temperature. Logging data while flexing the harness and warming the unit helps catch it.
P27C4 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor1 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P27C4
- MIL that comes and goes
- Occasional harsh or missed shift
Common causes of P27C4
- Most likelyFretting corrosion on connector terminals
- PossibleWire strand broken inside intact-looking insulation
- Less likelySolenoid winding that opens at operating temperature
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Pressure control solenoid pWiring harness
What each part of P27C4 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. |
| C4 | The exact fault in that area. |
What to do next
- Note P27C4 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 P27C4
What does P27C4 mean?
P27C4 means "Pressure Control Solenoid P Intermittent". P27C4 indicates that solenoid P works most of the time but its circuit or response briefly drops out. It is a generic code, so it means the same on every make.
Is it safe to drive with P27C4?
Drive gently and only to a workshop. With P27C4 the car can go into limp mode (reduced power) to protect itself.
Will P27C4 fail an emissions test?
Yes, it can. P27C4 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 P27C4 to fix?
Difficulty: medium. A typical repair takes 1 to 4 hours of work. This is a job for a workshop.
Will P27C4 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.