Secondary Air System Incorrect Flow Detected
The engine's secondary air system is not flowing air as expected.
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 system helps reduce emissions by injecting fresh air into the exhaust during cold starts. If it detects the air isn't flowing right, something’s likely wrong in that system.
What the computer is actually seeing
The engine control module (ECM) monitors the secondary air system operation using pressure sensors and airflow measurements. If the air flow does not meet expected levels during operation, it triggers the P244C code.
What a healthy reading looks like
Expected flow rates are usually between 5-10 L/min under a cold start condition with a pressure drop of less than 1 psi in the exhaust system.
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. Check for any obvious leaks in the secondary air system and intake piping.
- 22. Inspect the secondary air pump and ensure it operates when the engine is cold (you should hear it running).
- 33. Verify that the check valve is functioning properly by checking for backflow when the air pump is off.
- 44. Use a scan tool to read live data and check the actual airflow compared to the desired airflow from the ECM.
- 55. Inspect wiring and connectors for the secondary air pump and pressure/flow sensors; look for damage or corrosion.
Common causes
- Blocked secondary air passages
- Failed secondary air pump
- Faulty check valve in the air system
- Leaks in the intake or exhaust system
- Wiring issues to the secondary air pump or sensors
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
Yes, but emissions may be higher, and it could impact engine performance. Fix soon.
Will this code come back after clearing it?
If the underlying issue isn't resolved, the code will likely return.
Why does this code pair with other air injection codes?
These codes often relate to the same secondary air injection system, indicating multiple potential failures.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
Start guided diagnostic →