The P2258 code indicates that the engine control module (PCM) has detected a voltage in the secondary air injection system control circuit that is higher than the normal operating range. This typically signifies an electrical open circuit or a short to power within the system's control loop.
The relay responsible for powering the secondary air pump has failed internally or has burnt contacts.
Frayed, broken, or corroded wires in the control circuit have created an open circuit or a short to voltage.
An internal electrical failure within the pump motor can cause the circuit voltage to read outside of specifications.
Moisture or debris in the electrical connectors has increased resistance or caused a short.
The engine control module is incorrectly processing the circuit voltage or has an internal driver failure.
Yes, the vehicle will typically remain drivable, as the secondary air system is primarily used during cold starts to reduce emissions.
Generally, no. P2258 is an electrical circuit high code; mechanical clogs usually trigger different codes related to air flow or pressure.
No. It is highly uncommon for the PCM to be the cause of this code. You should exhaustively test the relay, pump, and wiring before considering a module replacement.