Cylinder 2 Injector Circuit High
The engine computer detected that cylinder 2's fuel injector circuit is receiving too much voltage, like a water faucet stuck in the open position sending excessive pressure. This prevents proper fuel spray control and can damage the injector or its wiring.
The ECM monitors the voltage drop across the fuel injector circuit during activation. It expects a controlled voltage pulse that energizes the injector solenoid briefly. If voltage remains abnormally high or the circuit resistance is too low, the ECM logs P0266.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Injector circuit voltage | 0-5V with controlled pulse timing | Sustained high voltage above expected pulse range |
| Injector circuit resistance | 10-16 ohms per injector | Below 8 ohms indicating short or shorted winding |
Code P0266 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.
Once the fault is repaired, P0266 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.