P0416 OBD-II Trouble Code: Secondary Air Injection System Switching Valve B Circuit Open

Our certified mechanics come to you · 12-month, 12,000-mile warranty

SCHEDULE P0416 DIAGNOSTIC Get a fair and transparent estimate upfront
Red-stars EXCELLENT RATING ON

Cost of diagnosing the P0416 code

P0416 is a diagnostic trouble code (DTC) for "Secondary Air Injection System Switching Valve B Circuit Open". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic for $70.00. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $30.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.

Cars Estimate Credit towards follow-up repair Earliest Availability
Ford$70.00$30.00
Toyota$70.00$30.00
BMW$70.00$30.00
SCHEDULE P0416 DIAGNOSTIC Get a fair and transparent estimate upfront

diagnostic check engine light

P0416 code definition

The powertrain control module (PCM) has detected a problem in the secondary air injection system, which reduces emissions by pumping ambient air into the exhaust stream.

What the P0416 code means

The PCM reads the condition of the secondary air injection system in increments of pressure and flow, which translate to input voltage from sensors. If input readings fluctuate by more than ten percent, a code will be stored and the malfunction indicator lamp (MIL) will illuminate. Some models require multiple drive cycles for the MIL to illuminate, but the code will usually be stored on the initial incident.

What causes the P0416 code?

  • Icing inside the pump in cold weather, due to a failed check valve which allows water or condensation to enter the pump and freeze

What are the symptoms of the P0416 code?

How does a mechanic diagnose the P0416 code?

Usually driven by the serpentine belt, the secondary air injection system uses a pump often called the “smog pump” to inject ambient air into the exhaust stream, reducing emissions. Heat-resistant silicon hoses direct cooler ambient air to the pump, while filtered air comes in through the air filter housing. This cooler air is directed into the exhaust system with silicon and steel lines, with a one-way check valve fitted on each exhaust hose to prevent condensation from backing up into the pump and causing problems. These valves are prone to failure.

Engines that use a V configuration usually feature dual inlet ports in the exhaust pipes and dual one-way check valves from the pump.

  • Test the check valves by attempting to blow air through them from both directions. Air should only flow through the valve in a single direction.
  • If air can flow through the valve in both directions, the valve has failed and should be replaced.
  • Inspect the hoses, lines and fittings for cracking, looseness and deterioration. Replace as needed.
  • If the check valves and lines all appear to be in good shape, perform a visual inspection of wiring, connectors and components. Repair/replace any damaged, disconnected, shorted or corroded parts as needed.
  • Connect a scanner or code reader to the diagnostic connector and record any stored codes.
  • Clear codes and test drive to see if codes return.
  • Check system fuses, referring to service manual for fuse location and values. Replace any blown fuses as needed.
  • After fuses are replaced, operate the secondary air injection system.
  • If fuse continues to blow, inspect for electrical shorts.

Common mistakes when diagnosing the P0416 code

Replacing the secondary air injection pump without devising a water drain on the pump housing can lead to repeated failures of the pump. It’s also essential to test one-way check valves for a proper diagnosis.

How serious is the P0416 code?

A P0416 code can lead to an illuminated MIL and a failed emissions test.

What repairs can fix the P0416 code?

  • Replacement of secondary air injection system pump
  • Replacement of secondary air injection system pump check valves
  • Repair/replacement of lines going to and from secondary air injection system pump

Additional comments for consideration regarding the P0416 code

More often than not, the check valves or the secondary air injection system pump are at fault. Failed check valves can introduce water back into the pump, and in cold weather this can cause the pump to seize or cause other types of catastrophic failure. Diagnosis should start with inspection of the pump and check valves. Other emissions-related codes may accompany a P0416 code, but it’s important to start with these components first.

Need help with a P0416 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

trouble codes
P0416
OBD-II

Fast and easy Check Engine Light is on Inspection service at your home or office.

SCHEDULE P0416 DIAGNOSTIC
Get a fair and transparent estimate upfront

Recent Check Engine Light is on Inspection reviews

Excellent Rating


YourMechanic Check Engine Light is on Inspection Service

Average Rating

4.5/5

Number of Reviews

3,484

Rating Summary
3,176
153
40
23
92
3,176
153
40
23
92

Richard

10 years of experience
415 reviews
Richard
10 years of experience
This is the second time I’ve had Richard work on my car. He always does an outstanding job and is quick, knowledgeable and professional. Highly recommended!!
2012 DODGE CHALLENGER - CHECK ENGINE LIGHT IS ON - LAS VEGAS, NEVADA

Michael

13 years of experience
372 reviews
Michael
13 years of experience
Mike was an absolute professional when he arrived. He walked me thru the whole process of my repairs and also made good recommendations for preventive issues. His mechanical knowledge and good customer services was a breath of air and greatly appreciated :-)
2007 CHEVROLET AVALANCHE - CHECK ENGINE LIGHT IS ON INSPECTION - MARIETTA, GEORGIA

Rodrigo

10 years of experience
85 reviews
Rodrigo
10 years of experience
Rodrigo was exactly on time, very professional and friendly. He assessed my car, let me know the exact problem when a previous mechanic from a shop in my area was unable to. I felt he was very honest and sincere letting me know the level of urgency that I deal with the issue. Absolutely no pressure. I will absolutely use Rodrigo the next time I need anything to do with my car and will tell everyone about him. This is such a great service, I will never go to another mechanic again. It is so convenient. I couldn’t be happier. :)
2013 SMART FORTWO - CHECK ENGINE LIGHT IS ON - LAS VEGAS, NEVADA

Ricardo

8 years of experience
223 reviews
Ricardo
8 years of experience
Great service and was very helpful on what maintenance my vehicle needed and what to expect in the future. Would definitely recommend to anyone and will.
2004 MITSUBISHI LANCER - CHECK ENGINE LIGHT IS ON - LOS ANGELES, CALIFORNIA

More related articles

How to Buy Fuel Treatments
Adding a fuel additive to your gas tank when you fill up is one way to clean vital engine parts of deposits, improve the performance of your engine,...
The Traveler’s Guide to Driving in Malaysia
CraigBurrows / Shutterstock.com Malaysia is a popular destination for many tourists today. The country has amazing sights and attractions that you will want to explore....
Veteran and Military Driver Laws and Benefits in Idaho
The state of Idaho offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch in the...

Related questions

Q: My honda CRV shows -28 on the screen . What does that mean?

The screen may be displaying a trouble code tied to a fault picked up by the vehicles computers. The code may stand for an item that needs to be reset or an electrical fault. Consider hiring an experienced technician like...

Q: Does the OBD system use more than lights to communicate with the driver?

Malfunction Indicator Lamps (MIL) and audible alarms are currently the only means by which the On-Board Diagnostics (OBD) system can inform the driver of any issues that adversely affect the operation of the engine or other electronically controlled system. The...

Q: Looking for info about most common OBD2 Codes

There are two (at least) quite distinct issues in regard to your general request: The first is, once a check engine light illuminates, what are the most "frequent" codes that are stored and thence downloaded, that is what does THAT...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1-800-701-6230 · hi@yourmechanic.com