OBD-II Trouble Code P0415 — Secondary Air Injection System Circuit Open

The P0415 code indicates that the vehicle’s ECM has detected an open circuit in the secondary air injection system. This disrupts airflow used to reduce exhaust emissions during cold starts and can trigger the Check Engine Light.

🔍 What Does Code P0415 Mean?

The Secondary Air Injection System helps minimize harmful emissions by injecting fresh air into the exhaust manifold. A P0415 fault means the ECM has detected an open circuit—indicating broken wiring or a disconnected solenoid that prevents voltage continuity.

⚠️ Common Symptoms

• Check Engine Light (CEL) illuminated
• Failed emission or smog test
• Air pump not engaging during startup
• Rough idle during the first few seconds of engine run
• Reduced overall fuel economy

🔧 Causes of P0415

• Open wiring or broken connection in the air injection circuit
• Faulty secondary air solenoid or pump relay
• Corrosion on electrical connectors
• Blown air injection fuse
• ECM internal circuit fault (rare)

🧰 Diagnosis Steps Using iCarsoft CR Max BT

1. Connect the iCarsoft CR Max BT scanner to the OBD-II port.
2. Turn ignition ON without starting the engine.
3. Read the stored DTCs and confirm P0415 is present.
4. Visually inspect all wiring between the ECM and the air pump solenoid.
5. Use the multimeter to check circuit continuity.
6. Run an actuator test to confirm solenoid function (via iCarsoft CR Max BT).
7. Repair or replace open circuits, then clear codes and verify the fix.

🧩 Repair Solutions for P0415

• Repair or replace open wires or connectors in the air injection system
• Replace the faulty solenoid valve or air pump relay
• Clean corroded terminals with electrical contact cleaner
• Reset the code and verify that the system now activates normally

✅ Prevention Tips

• Inspect air system wiring regularly, especially in humid regions.
• Use dielectric grease to protect connectors from corrosion.
• Perform periodic OBD-II scans to detect early issues.

The iCarsoft CR Max BT provides advanced system coverage, helping DIY owners and professional technicians diagnose and clear faults like P0415 efficiently.