P0281 — Cylinder 7 Contribution/Balance

Cylinder 7 Contribution/Balance. Basic catalogue definition; diagnostic details have not yet been reviewed.

Affected system: Powertrain

Symptoms

• Check-engine light, rough idle, uneven acceleration or loss of power may occur.
• Cylinder 7 contributes differently to engine torque balance; this is not automatically an injector electrical circuit code.

Possible causes

• Fuel injector 7 delivery restriction, leakage or spray imbalance; supply faults may also contribute.
• Cylinder-specific combustion problems such as weak compression or, on spark-ignition engines, ignition faults.

What to check

• Confirm P0281, identify cylinder 7 according to OEM numbering and review misfire/fuel codes.
• Use cylinder-balance/contribution data where available and compare with other cylinders under repeatable conditions.
• Inspect injector 7 wiring and fuel delivery; do not equate a contribution fault with a broken injector coil.
• If indicated, assess compression, ignition (petrol engines), intake leakage and fuel supply according to manufacturer procedures.
• Repair the measured root cause, then repeat contribution testing and check for returning DTCs.

Also written as: P0281-00, P028100, PO281 (some scan tools add the fault-type byte, e.g. -00).