Secondary Air Injection System Incorrect Airflow Detected
There's a problem with the secondary air injection system trying to help reduce emissions.
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 injection system is supposed to blow extra air into the exhaust to help burn off unburnt fuel, especially when the engine is cold. If it's not working right, the sensor sees that the airflow is off and flags a code.
What the computer is actually seeing
The engine control module (ECM) expects a certain airflow from the secondary air injection system upon startup. It measures this via the air flow sensor. If the measured airflow is significantly below or above expected values, it sets this code.
What a healthy reading looks like
Typically, the secondary air flow should be approximately 2-5 grams per second at engine startup. If it measures less than 1 gram per second, this code may trigger.
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 for the secondary air injection pump and sensor for any damage or corrosion.
- 22. Verify fluid levels—make sure there are no blockages in the system. Check hoses for leaks or disconnections.
- 33. Measure the operation of the secondary air injection pump with a multimeter—look for proper voltage (typically 12V) when energized.
- 44. Check the operation of the air flow sensor; it should show a reading corresponding to expected values at engine startup.
- 55. If all previous checks are good, test the check valve for proper operation—replace if defective.
Common causes
- Faulty secondary air injection pump
- Blocked or leaking hoses in the system
- Failed air injection check valve
- Faulty or disconnected air flow sensor
- Wiring issues or poor connections in the system
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's usually safe to drive, but emissions may increase, so fix soon.
Will this code come back after clearing it?
It could return if the underlying issue isn't fixed—monitor the system after repairs.
Why does this code often appear with P0410?
P0410 indicates the system is malfunctioning, while P0413 specifies incorrect airflow, both relate to the secondary air injection system.
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