P0419 Code: Secondary Air Injection System Control B Circuit Malfunction
🟠 Moderate severity · drivable
Drivable — this affects cold-start emissions, not drivability.
What P0419 means
The computer has detected a problem with the control circuit (usually the relay or driver) for the secondary air injection system on circuit B. This system pumps air into the exhaust at cold start to help the catalytic converter warm up.
Symptoms
- Check engine light is on
- Possible failed emissions test
- Air pump may not run at cold start
- No driving symptoms
Common causes
- most common: Faulty AIR system relay
- common: Damaged control wiring
- less common: Faulty air pump
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Replace the AIR system relay | Yes | $10–60 |
| Repair damaged control wiring | Mechanic | $50–150 |
| Replace the air pump | Mechanic | $200–500 |
Frequently asked questions
Can I drive with a P0419 code?
Yes. It affects cold-start emissions, not drivability, but fix it before an emissions test.
What is the most common cause of P0419?
A faulty AIR system relay or damaged control wiring.
How much does it cost to fix a P0419?
A new relay is $10–$60; wiring repairs are usually $50–$150.
Related codes
P0410
P0410 Code: Secondary Air Injection System Malfunction
P0415P0415 Code: Secondary Air Injection (AIR) Switching Valve B Circuit Malfunction
P0418P0418 Code: Secondary Air Injection System Relay A Circuit Malfunction
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.