P277C code meaning
Electric/Auxiliary Transmission Fluid Pump B Motor Stalled
Powertrain system Generic code P27xx codes Check engine light
What P277C means
P277C means the motor of auxiliary pump B is commanded to turn but stands still or nearly so. Volvo uses it: its technical journal 36774 covers 2024–2027 mild-hybrid S60, S90, V60/V90 Cross Country, XC40, XC60 and XC90 models with the Aisin TG-81SC eight-speed, where the TCM stores P277C07. If the code shows up only intermittently, no warning appears and stop-start still works, Volvo says to clear it and not to replace anything. Confirmed with a warning and dead stop-start, gearboxes built before serial 25M8L30144 are replaced, while later units go to engineering support first. Ford's pump A equivalent is P0C2A, which its 2024 summary links to a pump that may have lost prime. A jammed impeller or seized bearing is the classic cause.
P277C at a glance
- Check engine lightYes, usually on
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor0.3 to 12 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P277C
- Transmission warning message in the cluster
- Stop-start not working
- Shifts too early, too late or erratic
Common causes of P277C
- Most likelyJammed impeller or seized pump bearing
- PossibleKnown hardware issue in early gearboxes (Volvo TG-81SC before the serial break)
- PossiblePump lost prime because of low fluid
- Less likelyOne-off detection without a real fault
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Aux trans pump bPump motor
What each part of P277C 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. |
| 7C | The exact fault in that area. |
What to do next
- Note P277C 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 P277C
What does P277C mean?
P277C means "Electric/Auxiliary Transmission Fluid Pump B Motor Stalled". P277C means the motor of auxiliary pump B is commanded to turn but stands still or nearly so. It is a generic code, so it means the same on every make.
Is it safe to drive with P277C?
Drive gently and only to a workshop. With P277C the car can go into limp mode (reduced power) to protect itself.
Will P277C fail an emissions test?
P277C is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is P277C to fix?
Difficulty: workshop only. A typical repair takes 0.3 to 12 hours of work. This is a job for a workshop.
Will P277C clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.