OBD-II code P0280 indicates the powertrain control module (PCM) has detected an abnormally high voltage signal in the fuel injector control circuit for cylinder 7. A 'high' reading most often points to an open-circuit condition, meaning current is not flowing through the injector as expected, which typically prevents that injector from delivering fuel.
The most common cause. An open winding in the injector solenoid prevents current flow, so the driver voltage in the circuit stays high. Resistance typically reads as infinite or far outside specification.
Heat, vibration, oil, and coolant exposure frequently degrade the two-pin injector connector, producing high resistance or an open circuit that the PCM sees as a high-voltage condition.
Chafing, heat damage near exhaust components, rodent damage, or a pulled harness can break the injector feed or control wire, opening the circuit and triggering the code.
A corroded ground point or high resistance in the ground side of the injector circuit can prevent the driver from completing its path, raising the sensed voltage.
Possible but uncommon. The PCM's driver transistor for cylinder 7 could be shorted or open internally, but this is typically identified only after the injector and wiring have been ruled out.
Short trips to a repair facility are usually fine, but the cylinder will be running lean or not at all, which can overheat the catalyst over time and reduce power. Prolonged driving with an active misfire on the same cylinder is not recommended.
Almost never. P0280 is overwhelmingly caused by the injector itself or its connector and wiring, not the engine computer. Replacing the PCM is expensive and usually does not fix the problem unless the wiring and injector have already been verified good.
Sometimes the connector or harness is the only fault, especially if corrosion or a backed-out pin is found. If coil resistance tests within spec and the connector is restored, the code may clear without replacing the injector.
Each injector has its own dedicated driver in the PCM and its own pair of wires back to the connector. A fault specific to cylinder 7 (one bad coil, one damaged wire, or one corroded pin) will only affect that circuit, while the other cylinders continue to operate normally.