P2258 moderate

Secondary Air Injection System Control 'A' Circuit High

The P2258 code means the vehicle's onboard diagnostic system has detected: Secondary Air Injection System Control 'A' Circuit High. This is a moderate severity code.

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Keep driving?: Yes, but fix soon
DIY difficulty: moderate
Estimated cost: $100 - $500 (parts and labor)

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Common Symptoms

Check Engine Light on
Failed emissions test
Air pump may run continuously
Slight hissing noise from engine bay
No major drivability symptoms

Probable Causes (Ranked by Likelihood)

Open circuit in secondary air pump control wiring Very High
Short to voltage in control circuit High
Corroded relay socket Moderate
ECM driver open circuit Low

Step-by-Step Diagnostic Procedure

Check relay control circuit for opens
Inspect wiring for shorts to battery voltage
Test relay socket for corrosion
Verify ECM output signal

Frequently Asked Questions

What is the secondary air injection system?

The secondary air injection system pumps fresh air into the exhaust during cold start to help the catalytic converter reach operating temperature faster and reduce cold-start emissions.

Will this code cause my car to fail emissions?

Yes, secondary air injection codes will almost always cause an emissions test failure because the system is specifically designed to reduce startup emissions.

Can I delete the secondary air injection system?

Removing or disabling the secondary air system is illegal in most jurisdictions as it is a required emissions control component. The system should be repaired to maintain compliance.