What does P0278 mean?
The computer measures how much each cylinder speeds up the crankshaft when it fires. On engines that run this test (many Ford Powerstroke diesels and some gas engines), this code means cylinder 6 is contributing less, or more, than the others. That points at the injector or the mechanical health of that cylinder.
Codes are a starting point. They tell you which test failed, not which part to replace. Check for other stored codes and fix those in a sensible order.
Symptoms
- Rough idle
- Misfire or knock
- Smoke (white or black on diesels)
- Reduced power
Common causes
- Worn, sticking or leaking injector on cylinder 6
- Injector wiring or connector problem
- Low compression on that cylinder
- Fuel aeration or contamination (on diesels)
How to diagnose P0278
- Run an injector contribution or cylinder cut-out test with a scan tool.
- Check the injector wiring and connector.
- Run a compression or relative compression test.
- On diesels, check fuel quality and supply pressure.
How to fix it
- Replace the injector
- Repair wiring
- Repair mechanical issues
Estimated repair cost
Likely repairs for P0278 run from about $100 to $1,200, depending on the cause.
| Repair | Typical range (parts + labor) |
|---|---|
| Diagnostic fee (scan + testing) | $100 - $200 |
| Diesel injector replacement (one) | $400 - $1,200 |
| Compression / leak-down test | $100 - $250 |
These are rough US estimates for an independent shop in 2026, based on typical parts prices and standard labor times. Dealers, big trucks, luxury brands and high-cost areas often run higher. They are not quotes. Use the repair cost estimator to adjust for your vehicle.
How serious is P0278?
Moderate severity
Usually drivable short term, but a failing injector can get worse quickly, and on some engines it can damage a piston.
Make-specific notes
Powerstroke (Ford 6.0L / 6.4L / 6.7L)
Ford often reports injector problems with cylinder contribution codes. Ford numbers cylinders 1-4 on the passenger side and 5-8 on the driver side.
Always check open recalls and technical service bulletins for your VIN.
P0278 FAQ
What does P0278 mean?
P0278 stands for "Cylinder 6 Contribution/Balance". The computer measures how much each cylinder speeds up the crankshaft when it fires.
Can I drive with a P0278 code?
Usually drivable short term, but a failing injector can get worse quickly, and on some engines it can damage a piston.
How much does it cost to fix P0278?
It depends on the cause. The likely repairs for P0278 range from about $100 to $1,200 at an independent shop in the US, plus a diagnostic fee of roughly $100-$200. These are rough estimates; dealer prices and some vehicles run higher.
What is the most common cause of P0278?
The most common causes are: worn, sticking or leaking injector on cylinder 6; injector wiring or connector problem; low compression on that cylinder.