P27BF code meaning
Pressure Control Solenoid N Control Circuit Low
Powertrain system Generic code P27xx codes Check engine light
What P27BF means
P27BF indicates the control line of solenoid N is pulled too low, in practice a short to ground. GM's 23OBDG07 table for the Corvette dual-clutch gearbox checks synchronizer actuation valve 2 while its low-side switch is on: should the sense-pin voltage fall below about 1.7 V (tolerance 0.5 V), the driver chip reports a ground short; 150 ms confirmation, battery between 8.75 and 18 V, engine not cranking, Type A. With the line grounded the solenoid can be energized permanently and the controller loses control of it. Ford's TR9070 table calls the same event shorted switch on SPV2. A pinched harness against the case or water in a connector are frequent reasons.
P27BF 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 P27BF
- MIL on immediately
- Unintended gear actuation or locked-out gears
- Limp mode
Common causes of P27BF
- Most likelyControl wire chafed through to ground
- PossibleMoisture or corrosion bridging the connector
- Less likelySolenoid winding shorted to its housing
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Pressure control solenoid nWiring harness
What each part of P27BF 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. |
| BF | The exact fault in that area. |
What to do next
- Note P27BF 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 P27BF
What does P27BF mean?
P27BF means "Pressure Control Solenoid N Control Circuit Low". P27BF indicates the control line of solenoid N is pulled too low, in practice a short to ground. It is a generic code, so it means the same on every make.
Is it safe to drive with P27BF?
Drive gently and only to a workshop. With P27BF the car can go into limp mode (reduced power) to protect itself.
Will P27BF fail an emissions test?
Yes, it can. P27BF 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 P27BF to fix?
Difficulty: medium. A typical repair takes 1 to 4 hours of work. This is a job for a workshop.
Will P27BF clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.