P0416Generic code

P0416 Code: Secondary Air Injection System Switching Valve B Circuit Open

The P0416 code means the circuit of secondary air switching valve B is open, so the component gets no current when it is activated. Check the connector, the fuse and the wiring before you replace the valve. It does not affect driving, but it keeps the vehicle from passing an emissions inspection.

Severity
Low
Can I keep driving?
Yes, no immediate risk
Estimated cost
$50 to $500
Difficulty
Medium
System
Emissions Control
Applies to
All OBD2 vehicles

Updated Reviewed by Renzo Chacca

On this page

What the P0416 code means

On engines with two banks or two valves, valve B controls the secondary air flow to the second bank or to a second point in the exhaust.

The computer watches the control circuit from its own driver transistor. The P0416 code points to an open circuit: the component gets no current when it is activated. Before you replace the component, check the fuse, the relay, the connector and the wiring, because they are the most common cause.

If valve B fails, one bank gets no air after a cold start. It does not affect driving, but it keeps the vehicle from passing an emissions inspection.

Measure the resistance of the component at its connector. If it is infinite, the component is open inside. If it reads correctly, follow the control wire to the computer looking for a break, especially in the stretches near the exhaust and at intermediate connectors.

P0416 code symptoms

  • Check engine light on.
  • Usually no driving symptoms.

Likely causes of the P0416 code

  1. Connector unplugged or with a broken lock.
  2. Open coil. The resistance reads infinite.
  3. Cut wire. Check the rubbing points and the areas near the exhaust.
  4. Blown fuse, often from a short in the component itself.

How to diagnose the P0416 code step by step

  1. Activate the component with the scan tool and see whether it responds.
  2. Check the fuse and the relay.
  3. Measure the supply at the connector. You should see battery voltage with the key on or when it is activated.
  4. Measure the resistance of the component and compare it with the manual. Check the insulation to ground too.
  5. Check the control wire for continuity and for the absence of shorts.
  6. Identify valve B in the manual.
  7. Activate the valve with the scan tool.

How to fix the P0416 code

  • Repair the connector, the wiring or the supply.
  • Replace secondary air switching valve B if it does not respond with correct supply and control.
  • Clear the codes and verify that the monitor completes.

Technical reference data

  • 12 volt solenoid.
  • These are approximate values, so check the manufacturer data for your engine.

Brand-specific notes

This valve is used on V6 and V8 engines. Make sure you know which valve is B before you start testing, because the layout changes from one engine to the next.

P0416 on Toyota

Used on Toyota V6 and V8 engines.

P0416 on Lexus

Used on Lexus V6 and V8 engines.

P0416 on GM

Used on GM V6 and V8 engines.

Frequently asked questions about P0416

Can I drive with a P0416 code?
Yes. It normally does not affect driving. Repair it before the emissions inspection.
What does secondary air switching valve B do?
On engines with two banks or two valves, valve B controls the secondary air flow to the second bank or to a second point in the exhaust.
Do I always have to replace the part?
No. Check the fuses, relays, connectors and wiring first.
How much does it cost to fix P0416?
Roughly $50 to $500, depending on whether it is wiring or the valve itself. Diagnosing the P0416 code properly first keeps you from paying for parts you do not need.
What does the P0416 code mean?
It is a generic OBD2 code for an open circuit in secondary air switching valve B. The component does not get current when the computer activates it.
Will a P0416 code clear itself?
Only if the fault was a one-time glitch, such as a loose connector. A cut wire or an open coil will bring the code back.

Related codes

Questions about the P0416 code

There are no questions about this code yet. Tell us about your case: vehicle, symptoms and what you have already checked.