Secondary Air Injection System Performance
The secondary air injection system is not functioning properly.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The secondary air pump, which helps reduce emissions during startup, isn't doing its job as expected.
What the computer is actually seeing
The vehicle's engine control module (ECM) monitors the secondary air injection system for pressure and flow. If the air pump isn't running or if there's insufficient airflow detected for a specific time frame (usually within 1-3 minutes post cold start), it triggers this fault code.
What a healthy reading looks like
Expected operating pressures should be around 15-25 inches of water column during operation, and the air flow should match the required amount set by the ECM calculations based on engine load and speed.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Inspect the wiring and connectors to the secondary air injection pump for damage or corrosion. Decision: If any issues found, repair or replace as necessary.
- 22. Check the functionality of the secondary air injection pump by applying 12V directly to it. It should run smoothly. Decision: If it doesn't run, replace the pump.
- 33. Inspect the air passages for blockages or restrictions. Look for debris or collapsed hoses. Decision: Clear any obstructions found.
- 44. Examine the check valve for proper operation; it should allow air to flow in one direction only. Decision: If the valve is faulty, replace it.
- 55. Check for vacuum leaks in the system using a smoke machine or by listening for hissing sounds. Decision: Repair any leaks found.
Common causes
- Faulty secondary air injection pump
- Blocked or restricted air passages
- Faulty check valve
- Failed relay or wiring issue
- Vacuum leaks in the air system
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code active?
It's drivable but may lead to increased emissions and could fail an emissions test.
Will the problem come back after repair?
If the underlying issue is fixed and components are functioning correctly, it shouldn't return.
Why does this code appear with other codes?
Codes related to the air system often appear together due to interconnected components and shared issues.
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