P0416 Secondary Air Injection System Switching Valve B Circuit Open

P0416 points to an open circuit in Secondary Air Injection System Switching Valve B. The controller sees missing continuity or missing current in the valve B circuit.

Code details

Generic OBD-II · P0

System: Emissions
Code type: Generic (SAE / ISO controlled)
Standard: SAE J2012 / ISO 15031-6

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not replace the secondary air pump for P0416 when the fault points to the switching valve B circuit.

Symptoms of P0416

Check-engine light, often with no obvious change in how the car drives.
A failed emissions test or incomplete readiness monitors.
Sometimes a faint fuel-vapour smell (on EVAP codes).

Common causes of P0416

A worn catalytic converter or an oxygen/air-fuel sensor reading out of range.
EVAP leaks — a loose or failed gas cap, cracked hose, or purge/vent valve.
Exhaust leaks, fuel-trim problems, or a fault in a related monitor.

Useful checks before replacing parts

Measure valve B supply voltage, command continuity, solenoid resistance, relay output, fuse condition, and connector terminal fit.
Inspect for unplugged connectors, broken wiring, corrosion, open solenoid windings, harness strain, and damage near pump or exhaust components.
Verify the open at both the valve connector and controller side to avoid replacing a good valve for a harness fault.

Related OBD-II codes

These nearby emissions entries can help compare wording and pin down the fault area.