Secondary Air Injection System Switching Valve A Circuit Open
The Secondary Air Injection (SAI) system detects an open circuit in the air injection pump control path, preventing the system from injecting fresh air into the exhaust manifold during cold start and warm-up. This code affects emissions reduction but does not prevent the engine from running.
What You Might Notice
- Hissing or chugging noise from the SAI pump or pipes
- Loud whining sound from the pump area during cold starts
- Check Engine light illuminated
- No noticeable driveability issues
- Possible slight increase in tailpipe emissions
Most Common Causes
- 1
Burnt or broken SAI pump wiring
Open circuits, melted insulation, or disconnected terminals in the SAI pump circuit harness prevent the pump relay from activating the pump motor.
- 2
Faulty SAI pump relay
The relay that controls power to the SAI pump fails internally or has poor electrical contacts, breaking the control circuit.
- 3
Frozen SAI pump
In extreme cold climates, moisture inside the pump can freeze, jamming the pump impeller and triggering the open circuit fault.
- 4
Defective SAI pump or pressure sensor
The pump motor burns out, the pressure sensor fails, or corroded connectors prevent proper electrical communication in the SAI circuit.
How to Diagnose It
- 1
Check Burnt or broken SAI pump wiring — Open circuits, melted insulation, or disconnected terminals in the SAI pump circuit harness prevent the pump relay from activating the pump motor.
- 2
Check Faulty SAI pump relay — The relay that controls power to the SAI pump fails internally or has poor electrical contacts, breaking the control circuit.
- 3
Check Frozen SAI pump — In extreme cold climates, moisture inside the pump can freeze, jamming the pump impeller and triggering the open circuit fault.
- 4
Check Defective SAI pump or pressure sensor — The pump motor burns out, the pressure sensor fails, or corroded connectors prevent proper electrical communication in the SAI circuit.
How to Fix It
- 1
Inspect and repair SAI pump wiring
Visually inspect all wiring and connectors in the SAI pump circuit for burns, corrosion, loose terminals, or disconnections. Repair any damaged wiring by soldering or replacing the harness section as needed.
- 2
Test and replace SAI pump relay
Use a multimeter to test the relay coil resistance and switch continuity. If the relay fails resistance tests or shows open contacts, replace it with an OEM relay rated for your vehicle.
- 3
Replace SAI pump if frozen or defective
If the pump is frozen or motor testing shows no continuity, replace the entire SAI pump assembly. Ensure the new pump is properly grounded and all connectors are fully seated.
- 4
Clear code and perform verification test
After repairs, clear the fault code using a diagnostic scanner and perform a cold start test to confirm the SAI pump activates without noise or hesitation. Recheck for code recurrence after 50+ miles of driving.
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