Diagnostic trouble code P0278 — what it means, the common
causes, and how to confirm the real fault before replacing parts.
What does P0278 mean?
P0278 indicates: Cylinder 6 Contribution/Balance.
This relates to the Fuel & air metering system.
Common causes of P0278
valve lift changeover malfunction in cylinder 6
valves cannot be activated in cylinder 6
valves can no longer be switched off in cylinder 6
faulty injector on cylinder 6 detected by fault recognition system
What to check (live data)
engine speed sensor G28 signal (vibration/rough running detection)
intake manifold pressure (monitored continuously for irregularities)
Parts often involved in P0278
injector cylinder 6 (N84)
ZAS valve stroke changeover valve for cylinder 6
engine speed sender G28
Don't replace parts until the root cause is confirmed — many of these codes are caused by wiring, a connector or an upstream fault, not the part itself.
Get the confirmed root cause for P0278 — on YOUR vehicle
A code is a symptom, not a diagnosis. AutoDX Pro cross-checks several
independent assessments, pinpoints the actual root cause, gives you the
exact tests to confirm it, and shows the parts — only after the cause is
confirmed. Reads your scan-tool photo and decodes your VIN with open
recalls.
P0278 is a diagnostic trouble code: Cylinder 6 Contribution/Balance.
What are the common causes of P0278?
Common causes include: valve lift changeover malfunction in cylinder 6, valves cannot be activated in cylinder 6, valves can no longer be switched off in cylinder 6, faulty injector on cylinder 6 detected by fault recognition system. The exact cause depends on the vehicle — confirm it before replacing parts.
Can I keep driving with P0278?
It depends on the fault and your symptoms. Some causes are minor, others can damage components or affect safety. Get the root cause confirmed before deciding.
How do I fix P0278?
Confirm the actual root cause with targeted tests first, then replace only the part that's at fault. AutoDX Pro gives you the root cause, the exact tests, and the parts for P0278 on your specific vehicle.