Cause
Faulty secondary air injection relay
The relay switching the air pump, which draws heavy current for a short burst after a cold start. High current and infrequent use is what kills relay contacts, and it is the cheapest part in the system — so it belongs ahead of the pump it is usually blamed alongside.
Typically an easy fix. Often worth checking before paying anyone to look.
Codes this can cause (11)
Codes where this is a likely explanation first, rather than merely a possible one.
- P0418 Secondary Air Injection System Control A Circuit Likely for this code Low
- P0419 Secondary Air Injection System Control B Circuit Likely for this code Low
- P2258 Secondary Air Injection System Control A Circuit High Likely for this code Moderate
- P2444 Secondary Air Injection System Pump Stuck On Bank 1 Likely for this code High
- P2445 Secondary Air Injection System Pump Stuck Off Bank 1 Likely for this code Moderate
- P2446 Secondary Air Injection System Pump Stuck On Bank 2 Likely for this code High
- P2447 Secondary Air Injection System Pump Stuck Off Bank 2 Likely for this code Moderate
- P2448 Secondary Air Injection System High Air Flow Bank 1 Likely for this code Moderate
- P2449 Secondary Air Injection System High Air Flow Bank 2 Likely for this code Moderate
- P0410 Secondary Air Injection System A Moderate
- P2257 Secondary Air Injection System Control A Circuit Low Moderate
Information, not instruction
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