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P0416 Generic (SAE) Basic entry

Secondary Air Injection System Switching Valve 'B' Circuit Open

Updated 2026-10-02 · Auxiliary emission controls

Severity
Medium
Typical repair cost
40 – 350 EUR
System
Powertrain

What it means

P0416 means the engine control module cannot detect current flow in the Secondary Air Injection System Switching Valve 'B' circuit: the circuit is electrically open somewhere between the module, the connector and the component.

This entry is compiled automatically from the standard definition and typical diagnostic practice for this type of fault. A detailed, reviewed article is in preparation.

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Symptoms

  • Check engine light on, often with no change in driveability
  • Failed emissions inspection
  • Slight increase in fuel consumption
  • Smell from the exhaust in some cases

Common causes

  1. Damaged, chafed or corroded wiring in the Secondary Air Injection System Switching Valve 'B' circuit
  2. Corroded, loose or water-damaged connector terminals
  3. Failed Secondary Air Injection System Switching Valve 'B' component (sensor, solenoid or actuator)
  4. Poor ground connection for the module or component
  5. Faulty control module driver (rare, confirm all else first)

How to diagnose

  1. Read freeze frame data and note when the code set (cold start, under load, after rain)
  2. Inspect the Secondary Air Injection System Switching Valve 'B' connector for bent pins, corrosion and water; wiggle the harness with the engine running and watch live data
  3. Measure supply voltage and ground at the connector with the key on
  4. Check the signal wire for shorts to ground or battery and for continuity to the control module
  5. Test or substitute the Secondary Air Injection System Switching Valve 'B' only after wiring and connectors are confirmed good
  6. Clear the code and complete a drive cycle to confirm the repair

Frequently asked questions

Can I keep driving with P0416?

Usually yes for a short time, but expect reduced performance or higher fuel use. Have it diagnosed within a few days.

Will clearing P0416 fix it?

No. Clearing only erases the stored code; it returns as soon as the monitor runs again unless the cause is repaired.

Related codes

P0414P0415P0417P0418

Nearby codes in this group