What it means
The control module detects a high condition in the cylinder 6 injector circuit. This indicates an electrical circuit fault and does not by itself establish an injector flow problem.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The engine control module controls and monitors the injector circuit for cylinder 6. P0277 means the circuit signal is higher than expected, often because wiring is shorted to battery voltage or a supply wire is contacting the injector circuit; the code alone does not show that injector flow is affecting other cylinders.
Common causes
Most likely first.
- Wiring shorted to battery
- Connector pins corroded - high contact resistance
- Supply wire pinched against B+ source
Symptoms
- Check-engine light
- Rough idle or misfire
- Reduced power
- Increased fuel consumption
How to diagnose it
- Record freeze-frame data and check cylinder 6 misfire counts and available injector command data to identify when the high condition occurs.
- With the ignition off, inspect the cylinder 6 injector harness for pinched insulation, chafing, or contact with a battery-positive supply.
- Check the cylinder 6 injector connector for corrosion, loose pins, or heat damage.
- Use the wiring diagram and manufacturer's procedure to test for a short to voltage, open, or excessive resistance in the cylinder 6 injector circuit.
- Test the injector winding and control module driver if the wiring inspection and circuit checks do not locate the fault.
Common fixes
- Repair cylinder 6 injector wiring shorted to battery voltage or another supply.
- Reroute or secure pinched or chafed wiring and repair damaged insulation.
- Clean and secure the connector or replace faulty terminals.
- Replace the injector or repair the module driver only if its respective test fails.
Can I keep driving?
Limit driving if the engine misfires, since continued poor combustion can damage the catalytic converter. Avoid hard acceleration and stop if the engine runs severely rough or loses substantial power.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.