What Does P0415 Mean?
The PCM has detected a general malfunction in the secondary air injection switching valve B circuit. Valve B typically controls airflow to the bank 2 exhaust manifold on V-configuration engines. The system is unable to properly inject fresh air into the exhaust during cold starts to accelerate catalyst warm-up. The driver may notice the MIL illuminated and potentially higher tailpipe emissions during cold starts.
Common Causes
35%
Failed or stuck AIR switching valve B solenoid
25%
Open or corroded wiring/connector to switching valve B
20%
AIR system relay B failure
12%
Carbon or moisture contamination causing mechanical valve failure
8%
PCM driver circuit failure for valve B control
Diagnostic Steps
1
Check for companion codes on bank 1 (P0412/P0413). If only bank 2 is affected, the issue is isolated to the valve B circuit. Inspect the valve B electrical connector for corrosion, spread terminals, or moisture.
2
Measure resistance across the switching valve B solenoid — typical spec is 20-40 ohms. An open reading or very low resistance indicates a failed solenoid.
3
Command the AIR system on via bi-directional controls. Verify 12V is present at the valve B connector when commanded. If voltage is present but the valve doesn't click, the valve is mechanically stuck or the solenoid is dead.
4
If no voltage at the valve connector, trace the circuit back through the relay and fuse. Verify fuse integrity and relay operation by swapping with a known-good relay of the same type.
5
Physically inspect valve B for carbon deposits or corrosion on the valve disk. Some valves can be cleaned; others must be replaced as an assembly.
Estimated Repair Cost
$150 - $500
Parts + labor, varies by vehicle and location
The PCM has detected a general malfunction in the secondary air injection switching valve B circuit. Valve B typically controls airflow to the bank 2 exhaust manifold on V-configuration engines. The system is unable to properly inject fresh air into the exhaust during cold starts to accelerate catal...
The most common cause of P0415 (Secondary Air Injection System Switching Valve B Circuit Malfunction) is: Failed or stuck AIR switching valve B solenoid
Typical repair costs for P0415 range from $150 to $500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to continue driving. The AIR system is emissions-related only and does not affect engine performance or driveability. The vehicle will fail emissions testing and cold-start pollutant output will be higher than designed.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0415 to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Powertrain
System
Emission Control System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
