The air pump – secondary air injection system (AIS), is actually a part of the exhaust system.
Since no internal combustion engine is 100% efficient, there will always be some unburned fuel in the exhaust.
As a result, the air pump – secondary air injection system (AIS) was created. Over the years, two different systems were use. First, the pump type, later replaced by the pulse type.
The air pump – secondary air injection system (AIS), is the last resort, to minimize hydrocarbon emissions.
So, combustion requires fuel, oxygen and heat. But, without any one of the three, combustion cannot occur. Consequently, inside the exhaust manifold, there is sufficient heat, to support combustion. All we have to do, is introduce some oxygen, than any unburned fuel will ignite. Both systems, intercept those unburned fuels, but send them to different locations.
Air Injection Systems (AIS), Consist Of Mainly, Two Different Designs:
The First Design Was Know As, The Pump Type (Smog Pump)
It is responsible for, supplying fresh pressurized oxygen, into the exhaust stream, as it exits the exhaust manifold. Exhaust gases are at their hottest, as they leave the combustion chambers. So, introducing oxygen to the exhaust at this point, allows continued burning of the fuel mixture. All while traveling down the exhaust system and ultimately out the tailpipe.
NOTE: This combustion will not produce any power, but it will reduce high hydrocarbon emissions.
However, there is no control over this combustion. So, if the fuel content of the exhaust is high, explosions, that sound like popping, will occur. Consequently, there are times when under normal conditions, such as deceleration, when the fuel content is, high. And, under these conditions, we would want to shut off, the air injection system.
As a result, adding a air injection diverter valve, solves this problem. So, instead of turning the air pump off, it diverts the air, away from the exhaust manifold.
Air Injection Diverter Valve
So, the air pump diverter valve, allows air supplied from the air pump to go, into the exhaust stream. Consequently, to lower hydrocarbon and carbon monoxide tailpipe emissions. Consequently, it functions, as a one-way valve, allowing the air to pump through the exhaust.
Therefore, preventing the exhaust fumes from, leaking back into the secondary air injection system. This is also how engine backfires are controlled. When the air pump diverter valve fails, it can lead to a variety of problems. In addition, to a significant increase in the vehicle’s, tailpipe emissions. But, this is all done, after the combustion process is completed. That’s why, this device has no effect on engine performance.
The Second Design Was Know As, The Pulse Type
This system works during the cold start phase, when the catalytic converter is not yet active. The pulse type system works by taking advantage of the, negative pressure pulses created in the exhaust stream. So, as the engine cycles, this vacuum draws fresh oxygen, into the air injection lines. To achieve efficient warmup operation, a high secondary air flow rate must be achieved. And, needs to happen within, the first few seconds of engine startup.
And, the air flow rate must be maintained until oxygen sensor control is in operation. Air flow is maintained by an electric air pump. Once the oxygen sensors (O2) and catalytic converters have reached their operating temperatures. Then, the secondary air flow cuts off.
NOTE: This system works in harmony with, the exhaust gas recirculation (EGR) and catalytic converter, to complete the emission system.
A reed valve assembly, called the aspirator valve, is placed in the air injection system. This valve draws its air directly from the, clean side of the air filter. During engine idle, negative pressure pulses in the exhaust system draw air through the aspirator valve. Then, allows them to enter the exhaust stream, at the catalytic converter. As soon as the converter becomes active, the secondary air system is deactivated.
A Failed Air Pump, Will Produce A few Noticeable Symptoms:
- Engine is running rough
- Reduced power
- Check Engine Light comes on
- Exhaust odor
P0410 Engine Code
What the P0410 code mean?
P0410 is an OBD-II generic code, that the engine control module (ECM) detected. The engine (O2) sensor did not detect an increase in the (O2) level in the exhaust. After turning on the air injection system.
What causes the P0410 code?
- Low airflow, into the exhaust.
- The (O2) sensors are getting slow to respond, to the increase in (O2) in the exhaust.
- Too much back pressure, in the exhaust.
- The air injection pump relay contacts, not making contact.
Conclusion
So, a faulty pump is generally the most common cause, of the system failing. Also, too much moisture, can cause damage which results in, seizure of the pump. Finally, a faulty ground and voltage supply, can also cause the pump to fail.
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