P0416 low

Secondary Air Injection System Switching Valve B Circuit Open

The P0416 code means the vehicle's onboard diagnostic system has detected: Secondary Air Injection System Switching Valve B Circuit Open. This is a low severity code.

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Keep driving?
Yes, but fix soon
DIY difficulty
moderate
Estimated cost
$80 - $300 (parts and labor)
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Common Symptoms

  • Check Engine Light illuminated
  • No drivability symptoms
  • Secondary air system inactive on one bank during cold start
  • Failed emissions test

Probable Causes (Ranked by Likelihood)

  • Open circuit in switching valve B wiring Very High
  • Disconnected connector at valve B High
  • Burned-out switching valve B solenoid coil Moderate
  • Blown fuse in secondary air circuit Low

Step-by-Step Diagnostic Procedure

  1. Check the switching valve B connector for disconnection or damage

  2. Measure solenoid resistance -- OL reading confirms an open coil

  3. Check wiring continuity from ECM to valve B

  4. Verify secondary air system fuse is intact

  5. Apply 12V directly to the solenoid to test actuation

Frequently Asked Questions

Can I drive with code P0416?

Yes. The open circuit in valve B only affects cold-start secondary air injection on one exhaust bank. Normal driving is unaffected.

How is P0416 different from P0413?

P0413 refers to switching valve A (bank 1) circuit open, while P0416 refers to switching valve B (bank 2) circuit open. The diagnostic process is the same but applied to the opposite exhaust bank.

Could both P0413 and P0416 set at the same time?

Yes. If a shared fuse, relay, or common ground wire fails, both switching valves can lose power simultaneously, setting codes for both banks.

Sources

This page is built from documented references. Verify against your own service info before repair work.

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