P27BB code meaning
Pressure Control Solenoid N Electrical
Powertrain system Generic code P27xx codes Check engine light
What P27BB means
P27BB is a catch-all electrical code for pressure control solenoid N, and no manufacturer documents it publicly. The two makers known to use solenoid N, GM on the Corvette dual-clutch unit (23OBDG07) and Ford on the TR9070, both split electrical faults of this synchronizer valve into separate codes instead: P27BD covers an open load, P27BF a grounded line and P27C0 a line shorted to battery voltage. A controller with a less detailed driver stage could report all of these under P27BB. CARB 13 CCR 1968.2 requires circuit monitoring of such output components. Checks therefore cover coil resistance, connector pins inside the transmission and the harness to the TCM.
P27BB 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 P27BB
- MIL on
- Gears served by solenoid N unavailable
Common causes of P27BB
- Most likelySolenoid N coil open or shorted
- PossibleCorroded or loose internal transmission connector
- PossibleDamaged harness between TCM and transmission
- Less likelyFaulty output driver in the TCM
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 P27BB 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. |
| BB | The exact fault in that area. |
What to do next
- Note P27BB 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 P27BB
What does P27BB mean?
P27BB means "Pressure Control Solenoid N Electrical". P27BB is a catch-all electrical code for pressure control solenoid N, and no manufacturer documents it publicly. It is a generic code, so it means the same on every make.
Is it safe to drive with P27BB?
Drive gently and only to a workshop. With P27BB the car can go into limp mode (reduced power) to protect itself.
Will P27BB fail an emissions test?
Yes, it can. P27BB 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 P27BB to fix?
Difficulty: medium. A typical repair takes 1 to 4 hours of work. This is a job for a workshop.
Will P27BB clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.