P0277 Injector Circuit High (Cylinder 6) — Causes & Fix

What Does P0277 Mean?

P0277 is a generic OBD-II code meaning the Engine Control Unit measured a signal voltage above the expected window in the fuel injector circuit for cylinder 6. A 'high' circuit reading usually points to a break in the circuit, a short to battery voltage, or an injector coil with too much resistance. The ECU will often disable fuel delivery to cylinder 6 to protect the driver stage, so the engine runs with a dead cylinder until the fault is repaired.

P0277 at a Glance

• What it means: The ECU has measured a voltage above the expected range in the cylinder 6 injector circuit.
• Most common cause: Injector solenoid resistance out of specification, wiring short, or connector corrosion.
• Severity: Moderate to serious — the ECU may cut fuel to cylinder 6, causing a misfire.
• Can you drive?: Short distances only. Prolonged driving risks DPF and catalytic converter damage.
• Typical repair cost: £100-£350 for injector replacement; £40-£100 for wiring repair.