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DTC code page

P0415: Secondary Air Injection System Switching Valve B Circuit Malfunction

Quick answer: The ECU detected an electrical fault in the secondary air injection switching valve B circuit.

Drivers also search this fault as secondary air valve B circuit malfunction, P0415 switching valve B, air injection valve B electrical fault.

Severity: medium Family: powertrain Related paths: 7
Meaning

What P0415 usually means

P0415 mirrors P0412 on the B side of the secondary-air system. On platforms with separate control paths, banks, or staged valves, this code tells you the problem is in the valve B control circuit rather than the pump as a whole. Diagnosis follows the same logic: failed solenoid coil, missing feed, bad ground or driver path, connector corrosion, or wiring damage near heat and moisture sources.

Fast triage

Start here before chasing parts

  • Scan first: save freeze-frame and pending codes before clearing anything.
  • Confirm the complaint: compare the stored code with current drivability symptoms.
  • Use context: trims, live data, and related codes usually narrow the fault faster than guesswork.
  • Work simplest to hardest: leaks, connectors, maintenance items, and known patterns before expensive components.
Initial checks

What to check first

  • Identify whether valve B serves a separate bank or stage so you understand what part of the system is being named.
  • Inspect the connector and harness before condemning the control module.
  • Check coil resistance and commanded power/ground during the cold-start test window.
Driving risk

Can you keep driving?

P0415 usually is not an immediate driveability crisis, but it leaves part of the cold-start emissions strategy disabled and can block readiness.

Moderate urgency: This code often allows short-term driving, but the right fix usually comes faster when you diagnose it early instead of waiting for more codes.
Likely causes

Common causes behind this code

  • Valve B coil failed or out of range
  • Open, high resistance, or intermittent wiring in the B circuit
  • Connector corrosion, water intrusion, or loose terminal fit
  • Lost shared feed or control path affecting valve B
  • Valve B mechanically stuck and overloading or confusing the circuit

Cause phrases often tied to this code: valve B coil failure, connector corrosion, open wiring, driver fault, stuck switching valve B.

Diagnostic order

Suggested workflow

  1. Review freeze-frame and system layout for the valve B role on this vehicle.
  2. Inspect harness routing and connector condition at valve B.
  3. Measure coil resistance and verify supply and control operation under command.
  4. If electrical behavior looks normal, confirm valve B actually moves and does not bind mechanically.
  5. Retest cold-start secondary-air response after repair.
Avoid guesswork

Common mistakes

  • Confusing valve B with valve A and replacing the wrong component.
  • Ignoring vehicle-specific plumbing layout when the system uses more than one valve.
  • Assuming the pump must be bad because the code mentions the secondary-air system.
Repair path

Practical fix guidance

  • Repair the named B-circuit fault and confirm the system now routes air correctly during cold start.
  • Protect the repaired harness from the same heat and moisture that caused the original failure.
  • If both A and B codes appear, check shared feeds and grounds before replacing two valves blindly.
Vehicle context

Affected brands in this MVP

Brand hubs help broaden internal linking now and can evolve into make-specific diagnostic notes later.

Aliases and common searches

English phrases tied to P0415

Useful when the driver knows the wording but not the exact DTC yet.

  • secondary air valve B circuit malfunction
  • P0415 switching valve B
  • air injection valve B electrical fault
Related search intent

Queries this page can answer naturally

  • P0415 code meaning
  • what does P0415 mean
  • secondary air valve B circuit malfunction
FAQ

Quick questions about P0415

Is P0415 the same as P0412?

It is the same type of fault, but on switching valve B instead of valve A.

Can I diagnose P0415 without knowing the system layout?

Not well. You need to know what valve B actually controls on that engine.

Does P0415 always mean the valve is bad?

No. Wiring, connectors, feeds, and driver faults can all trigger it.