Secondary Air Injection System Switching Valve A Circuit
Problem with the secondary air injection control valve circuit.
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What it means (plain English)
The secondary air injection system helps reduce emissions by introducing air into the exhaust to help burn off excess hydrocarbons. When the control valve circuit fails, the system can’t operate correctly, leading to increased emissions and possible inspection failures.
What the computer is actually seeing
The engine computer monitors the secondary air injection system, including the flow of air and the operation of the control valve. If it detects a problem like an open circuit, short circuit, or incorrect voltage in the valve circuit, it triggers the P0416 code.
What a healthy reading looks like
The control valve should see around 12 volts when activated. There should be a change in resistance when the valve operates, typically between 5-20 ohms.
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 leading to the secondary air injection control valve for any damage or corrosion.
- 22. Check the fuse for the secondary air injection system; replace if blown.
- 33. Measure voltage at the valve with the engine running; should be around 12V. If not, trace wiring back to the ECM.
- 44. Check the resistance of the secondary air injection control valve; should be between 5-20 ohms. If outside this range, replace the valve.
- 55. If the wiring and valve are good, consider testing or replacing the ECM.
Common causes
- Faulty secondary air injection control valve
- Open or shorted wiring in the circuit
- Corroded connectors
- Blown fuse for the secondary air injection system
- Faulty engine control module (ECM)
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's safe to drive, but you may notice higher emissions and potential inspection failures.
Will this code come back after I clear it?
Yes, if the underlying issue isn't fixed, the code will likely return.
Why does this code sometimes pair with other codes?
Commonly, issues like a faulty air injection system can cause multiple related codes to show up.
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