Injector Circuit/Open Cylinder 6
The P0206 code indicates that the Powertrain Control Module (PCM) has detected a malfunction or open circuit in the fuel injector circuit for cylinder number 6. The PCM sets this code when it monitors the voltage or resistance of the injector circuit and finds it falls outside the manufacturer's expected operating range.
This code is considered high severity because driving with a dead cylinder can cause raw fuel to enter the exhaust, potentially damaging the catalytic converter. It should be diagnosed and repaired immediately to prevent further engine or exhaust system damage.
Common symptoms
- Illuminated or flashing Check Engine Light
- Engine misfire or rough idle
- Noticeable lack of engine power during acceleration
- Decreased fuel economy
- Strong smell of unburned fuel from the exhaust
Likely causes
- Faulty or failed fuel injector on cylinder 6
- Damaged, broken, or disconnected wiring in the cylinder 6 injector harness
- Corroded or loose electrical connector at the cylinder 6 injector
- Open or shorted circuit between the PCM and the fuel injector
- Faulty Powertrain Control Module (PCM) or injector driver (rare)
What to check before replacing parts
Visually inspect the wiring and connector at the cylinder 6 fuel injector
Look for: Look for disconnected plugs, broken wires, melted insulation, or corrosion on the connector pins that would cause an open circuit.
Listen to the cylinder 6 fuel injector with a mechanic's stethoscope while the engine is running
Look for: A steady clicking sound indicates the injector is operating; silence indicates it is not receiving a signal or is mechanically stuck.
Test the resistance of the cylinder 6 fuel injector using a digital multimeter
Look for: The resistance should match the manufacturer's specification (typically between 10 to 18 ohms); an infinite reading (OL) means the injector coil is internally open and requires replacement.
Check for proper voltage at the injector connector with the key on, engine off (KOEO)
Look for: You should see battery voltage (around 12 volts) on the power feed wire; lack of voltage indicates a wiring issue from the ASD relay or fuse.
Test the ground pulse signal from the PCM using a noid light plugged into the injector connector
Look for: The noid light should flash rapidly while cranking or running the engine; if it stays off or stays on solid, there is a wiring short or a faulty PCM driver.
This page explains the generic P0206 definition and is general reference information, not a diagnosis for your specific vehicle. Actual causes, severity, and repairs vary by make, model, engine, and mileage — always confirm with a scan tool and a qualified technician before replacing parts.
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