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.
- 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
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.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
-
Check the switching valve B connector for disconnection or damage
-
Measure solenoid resistance -- OL reading confirms an open coil
-
Check wiring continuity from ECM to valve B
-
Verify secondary air system fuse is intact
-
Apply 12V directly to the solenoid to test actuation
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
- Cross-checked against the SAE J2012:2002 DTC table (2026-08-27)archived scan of the SAE standard — readable copy, not SAE’s current edition
Commonly Affected Vehicles
- 2002-2013 BMW 745i
- 2004-2015 Audi Q7
- 2003-2014 Porsche Cayenne
- 2005-2016 Volkswagen Touareg
- 2006-2017 Subaru Tribeca
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