P2381 means the powertrain control module has detected a voltage signal from the EGR system's "Sensor D" that is above the expected range. "Sensor D" is a manufacturer-specific label that may refer to an EGR position, temperature, pressure, or differential pressure sensor. A high circuit reading almost always points to a sensor, wiring, or connector fault rather than the engine computer itself.
The sensor can fail internally and send a continuous out-of-range high voltage signal back to the PCM. This is the single most common cause of a circuit-high code.
Damaged wire insulation can let the sensor signal wire contact a higher-voltage source, such as the 5-volt reference or battery voltage circuit, driving the reading high.
Corroded, bent, loose, or oil-contaminated terminals can raise resistance or create false high-voltage readings that mimic a failed sensor.
Severe carbon restriction can alter exhaust pressure or temperature at the sensor enough to push readings outside the expected range on some designs.
A rare cause. The PCM input circuit could misread a good sensor signal, but this should only be considered after the sensor and wiring are proven correct.
Short trips are usually acceptable, but prolonged driving may increase combustion temperatures and emissions. It is best to diagnose and repair it soon.
Carbon cleaning can help if passages are restricted, but it will not repair a failed sensor or a shorted wire. Those are far more common causes.
No. PCM failure is an uncommon cause of this code. Most cases are resolved by replacing the sensor or repairing the wiring and connector.
It is a manufacturer-specific identifier and may refer to an EGR position, temperature, pressure, or differential pressure sensor. Consult service information for the exact component on the vehicle.