P027A code meaning
Fuel Pump Module B Control Circuit/Open
Powertrain system Generic code P02xx codes Check engine light
What P027A means
On demand-controlled fuel systems the engine module does not drive the pump itself but sends a pump control module the desired pump output on a separate control line, usually as a duty cycle; the module reports back on a monitor line or via CAN. Module B is a second pump module, for example on dual-tank commercial vehicles. P027A is the counterpart of P025A: the control line from the engine module to pump module B is open or faulty. No manufacturer using P027A was found – Ford reports line faults of both modules together under P025A, GM only uses P025A; the description follows CARB's circuit monitoring requirement and Ford's module B check. If the second tank's pump gets no valid command, fuel may run short when running from that tank.
P027A at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor1 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P027A
- Check engine light (manufacturer-dependent)
- Fuel shortage when running from the second tank
- Starting problems, surging
Common causes of P027A
- Most likelyControl line to the pump module open or shorted, often along the frame
- Most likelyConnector at the pump module corroded or wet (module often mounted on the frame)
- PossiblePump control module faulty (input)
- PossibleModule ground or supply poor
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Fuel pump control module bFuel pump control wiringEngine control module
What each part of P027A means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 2 | Area: fuel and air metering (injector circuit). |
| 7A | The exact fault in that area. |
What to do next
- Note P027A 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 P027A
What does P027A mean?
P027A means "Fuel Pump Module B Control Circuit/Open". On demand-controlled fuel systems the engine module does not drive the pump itself but sends a pump control module the desired pump output on a separate control line, usually as a duty cycle; the module reports back on a monitor line or via CAN. It is a generic code, so it means the same on every make.
Is it safe to drive with P027A?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P027A fail an emissions test?
Yes, it can. P027A 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 P027A to fix?
Difficulty: medium. A typical repair takes 1 to 3 hours of work. This is a job for a workshop.
Will P027A clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.