The diagnostic trouble code P0419 indicates an intermittent fault in the Secondary Air Injection System Switching Valve “A” circuit. This means the PCM (Powertrain Control Module) has detected erratic or fluctuating electrical signals from the air injection control valve, which manages air flow into the exhaust for emissions reduction.
What Does Code P0419 Mean?
Modern vehicles use a Secondary Air Injection System (SAIS) to inject fresh air into the exhaust during cold starts to help burn unburned fuel. When the Switching Valve “A” circuit shows an intermittent electrical signal, the ECM logs P0419 and may disable the air pump system.
| Code | Description |
|---|---|
| P0419 | Secondary Air Injection System Switching Valve “A” Circuit Intermittent |
Common Symptoms of P0419
- Check Engine Light (CEL) illuminated
- Failed emissions test
- Reduced engine performance during startup
- Possible air pump noise or relay clicking
- Stored related codes such as P0410 or P0414
Possible Causes
- Intermittent open or short in the air injection valve circuit
- Faulty Secondary Air Injection Valve (Solenoid “A”)
- Corroded or loose connector at the valve or relay
- Defective air pump relay or wiring damage
- Failed PCM driver circuit
How to Diagnose and Fix P0419
- Inspect Wiring and Connectors: Check for corrosion, loose terminals, or broken wires leading to the air switching valve.
- Test Voltage: Use a multimeter or iCarsoft CR Max BT to verify voltage at the valve connector while commanding the air system on.
- Activate the System: Use the scanner’s active test function to operate the Secondary Air Injection Valve and check for proper clicking or air flow.
- Check the Relay: Inspect the air pump relay and fuses for continuity and corrosion.
- Replace the Valve or Relay: If the signal intermittency persists, replace the faulty switching valve or relay, then clear the DTC.
Tip: With the iCarsoft CR Max BT, you can perform active tests on the secondary air injection system to confirm whether the valve responds properly before replacing any components.
Recommended Diagnostic Tools
- iCarsoft CR Max BT – Advanced bidirectional diagnostic tool for full-system analysis and active component testing.
- iCarsoft CR Ultra P – Professional-grade diagnostic scanner for emission systems and advanced live data monitoring.
Summary
OBD-II code P0419 indicates an intermittent issue in the Secondary Air Injection System Switching Valve “A” circuit. With a professional diagnostic tool like iCarsoft CR Max BT, you can perform active tests, verify circuit integrity, and fix the issue efficiently without unnecessary parts replacement.
