OBD-II Fault Code

P0416: Secondary Air Injection System Switching Valve B Circuit Open

Meaning, symptoms, likely causes, diagnostic checks and repair guidance for P0416.

System family

Powertrain

Generic/SAE

Repair category

Electrical circuit / sensor

Use this category to narrow your checks before replacing parts.

Severity

Medium

Severity is a general guide. Confirm with scan-tool data and vehicle symptoms.

What P0416 usually means

Secondary Air Injection System Switching Valve B Circuit Open.

Common symptoms

Check Engine light; Poor drivability or reduced fuel economy depending on fault

Likely causes

Open circuit; Disconnected connector; Broken wire; Failed component

Diagnostic checks

Scan all modules and record freeze-frame data before clearing codes; Check battery voltage and related fuses; Check connector fitment and continuity from module to component

Repair guidance

Repair open wire/connector or replace the failed component after continuity test

Verification after repair

Clear code, road-test through the same drive condition, then rescan

Note: Confirm vehicle make/model/year because manufacturer-specific codes can vary. A DTC identifies a circuit or system condition, not always the failed part.