<ul> <li><b>Engine Light ON (or Service Engine Soon Warning Light)</b>: The illumination of the engine light indicates a problem with the Secondary Air Injection System Control 'A' Circuit. This could be due to a low voltage condition in the circuit.</li> <li><b>Poor Engine Performance</b>: A malfunction in the Secondary Air Injection System can lead to reduced engine efficiency and performance. This is often caused by issues such as a faulty air pump, defective relay, or wiring problems.</li> <li><b>Failed Emissions Test</b>: The Secondary Air Injection System helps reduce emissions. A failure in this system can result in higher emissions, leading to a failed emissions test. Potential causes include a malfunctioning air pump or control valve.</li> <li><b>Unusual Noises from the Engine</b>: A failing air pump or related components may produce unusual noises, indicating a problem with the Secondary Air Injection System. This could be due to mechanical failure or electrical issues within the system.</li> </ul>

<ul><li>The secondary air system relay may be faulty, preventing proper operation of the air injection system.</li><li>An open or shorted harness in the secondary air system relay can disrupt the circuit, leading to this error code.</li><li>Poor electrical connections in the secondary air system relay circuit can cause intermittent or complete failure of the system.</li><li>A malfunctioning secondary air system pump can result in insufficient air injection, triggering the error code.</li></ul>

<ul> <li><b>Retrieve Codes and Freeze Frame Data</b>: Connect the diagnostic scanner to the vehicle's diagnostic port. Retrieve all stored codes and pertinent freeze frame data. Write down this information for reference.</li> <li><b>Clear Codes and Test Drive</b>: Clear the codes and test drive the vehicle until the code is restored or the PCM enters readiness mode. If the code is restored, proceed with the diagnosis.</li> <li><b>Perform Visual Inspection</b>: Inspect related wiring and connectors for any signs of damage such as cuts, burns, or corrosion. Repair or replace any damaged wiring or connectors.</li> <li><b>Check Secondary Air Injection System Control Voltage</b>: Use a digital volt/ohmmeter (DVOM) to test the secondary air injection system control voltage at the appropriate connector pin. If no voltage is detected, check the system fuses and replace any blown or defective fuses.</li> <li><b>Test Circuit at PCM Connector</b>: If voltage is detected at the secondary air injection system control connector, test the corresponding circuit at the PCM connector. If no voltage is detected, suspect an open circuit between the sensor and the PCM.</li> <li><b>Inspect PCM</b>: If voltage is detected at the PCM connector, suspect a defective PCM or a PCM programming error. Consider reprogramming or replacing the PCM if necessary.</li> <li><b>Check for Technical Service Bulletins (TSBs)</b>: Search for any TSBs that match the stored code, vehicle year, make, model, and engine. A relevant TSB may provide a quick solution to the issue.</li></ul>

<p>The DTC code P2257 indicates a problem with the Secondary Air Injection System Control 'A' Circuit Low. This is a critical issue as it affects the vehicle's emissions control system.</p><ul><li><b>Immediate Actions:</b> Inspect and repair the wiring and connectors associated with the air injection system.</li><li><b>Potential Risks:</b> Delayed repair can lead to increased emissions, potential engine damage, and failure to pass emissions testing.</li></ul>