What does code P0418 mean?
The ECU detects a malfunction in relay A of the secondary air injection system, preventing proper pump activation.
OBD-II Code
P0418 — Secondary Air Injection System Relay A Circuit Malfunction
The ECU detects a malfunction in relay A of the secondary air injection system, preventing proper pump activation.
Common symptoms
- Secondary air pump does not activate
- high emissions
- failed emissions test
Possible causes
- Burned relay
- blown fuse
- damaged wiring
Initial recommendation
Check relay A operation, inspect related fuses and wiring, replace faulty components.
Safety notice
This information is for guidance only and does not replace a physical vehicle inspection or diagnosis by a qualified mechanic. If the vehicle has severe power loss, smoke, a fuel odor, overheating, brake or steering problems, or any unsafe behavior, avoid driving it and seek professional inspection.
Analyze this code with MecaOBD
Use the app to combine code P0418 with your vehicle's actual symptoms for more complete diagnostic guidance.
Go to the app View more codes