Q: Strange P0410 SES code issue with Sec A.I.R. System
12-18-2013, 11:07 AM
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Q: Strange P0410 SES code issue with Sec A.I.R. System 2002 Z28, 74K miles. Yesterday got an SES light, scanner code P0410. No other codes seen.
I tried a search for info with this system. First inclination was to remove it all and tune it, but it's the wife's car and she said no.
Searching the forums, I found this handy:
http://www.gearchatter.com/viewtopic9013.php
Good to know I'd already done most of these checks. The AIR pump relay is verified to be good, so I decided to check operation. Pulled the fenderwell AIR pump hose connection apart. Then started up cold. Interestingly, NO AIR pump discharge was felt, and pulled the intake line from the air cleaner and no suction- thus the pump isn't working even at full cold startup.
However, the weird thing is that the hose going to the air injection cutoff valve to both check valves was pulse sucking air IN to the hose. I figured if the check valves were leaking, they would push exhaust out the hose. I checked with a piece of paper and sure enough, it was pulse sucking. And doing a pretty good job of it. So I don't think there was any flow restrictions.
So I'm confident there's no exhaust coming back, indicating the checkvalves must be operating correctly.
I put the fenderwell hoses back together, then checked at the pump suction at the air cleaner and felt suction pulses there too. So the sucking was pulling through the pump from the air cleaner.
After the engine started to warm up, the solenoid that controlled the air injection cutoff valve vacuum kicked on and the cutoff valve closed and the sucking stopped. So I'm kinda confident the air injection cutoff valve is working as well.
So I'm 99% confident the AIR pump is hosed and replacing it will restore proper operation and I can clear the code. Have a new GM one on the way.
Has anyone heard of this sucking phenomenon? Is is due to the educator effect on the exhaust manifold actually drawing in air through the checkvalves during the exhaust evacuation in the manifold?
I tried a search for info with this system. First inclination was to remove it all and tune it, but it's the wife's car and she said no.
Searching the forums, I found this handy:
http://www.gearchatter.com/viewtopic9013.php
Good to know I'd already done most of these checks. The AIR pump relay is verified to be good, so I decided to check operation. Pulled the fenderwell AIR pump hose connection apart. Then started up cold. Interestingly, NO AIR pump discharge was felt, and pulled the intake line from the air cleaner and no suction- thus the pump isn't working even at full cold startup.
However, the weird thing is that the hose going to the air injection cutoff valve to both check valves was pulse sucking air IN to the hose. I figured if the check valves were leaking, they would push exhaust out the hose. I checked with a piece of paper and sure enough, it was pulse sucking. And doing a pretty good job of it. So I don't think there was any flow restrictions.
So I'm confident there's no exhaust coming back, indicating the checkvalves must be operating correctly.
I put the fenderwell hoses back together, then checked at the pump suction at the air cleaner and felt suction pulses there too. So the sucking was pulling through the pump from the air cleaner.
After the engine started to warm up, the solenoid that controlled the air injection cutoff valve vacuum kicked on and the cutoff valve closed and the sucking stopped. So I'm kinda confident the air injection cutoff valve is working as well.
So I'm 99% confident the AIR pump is hosed and replacing it will restore proper operation and I can clear the code. Have a new GM one on the way.
Has anyone heard of this sucking phenomenon? Is is due to the educator effect on the exhaust manifold actually drawing in air through the checkvalves during the exhaust evacuation in the manifold?
02-13-2014, 05:38 PM
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The weird sucking is the Exhaust. Since its blowing air out the tailpipes at idle it draws a small vacuum. Kinda like a venturi effect. if you want to test this take the secondary air pipe off the exhaust manifold and try your paper test at idle..... 
once exhaust pressure in the exhaust gets high enough it will blow out toward you, but at idle it creates vacuum.
once exhaust pressure in the exhaust gets high enough it will blow out toward you, but at idle it creates vacuum.
02-25-2014, 12:52 PM
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"Has anyone heard of this sucking phenomenon?"
No but I wish I had met her!
I throw the PO416 code Right bank air injection. I replace the check valves and made sure all passages are open. I can reset it and drive 30 miles or so before it comes back. Just enough to pass inspection. I would like to fix this. I know I should not assume anything but do since the left bank seems to be operational and doesn't throw the PO410 code for both sides. It is an annoyance I would like to fix.
No but I wish I had met her!
I throw the PO416 code Right bank air injection. I replace the check valves and made sure all passages are open. I can reset it and drive 30 miles or so before it comes back. Just enough to pass inspection. I would like to fix this. I know I should not assume anything but do since the left bank seems to be operational and doesn't throw the PO410 code for both sides. It is an annoyance I would like to fix.
02-25-2014, 05:15 PM
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"Has anyone heard of this sucking phenomenon?"
No but I wish I had met her!
I throw the PO416 code Right bank air injection. I replace the check valves and made sure all passages are open. I can reset it and drive 30 miles or so before it comes back. Just enough to pass inspection. I would like to fix this. I know I should not assume anything but do since the left bank seems to be operational and doesn't throw the PO410 code for both sides. It is an annoyance I would like to fix.
No but I wish I had met her!
I throw the PO416 code Right bank air injection. I replace the check valves and made sure all passages are open. I can reset it and drive 30 miles or so before it comes back. Just enough to pass inspection. I would like to fix this. I know I should not assume anything but do since the left bank seems to be operational and doesn't throw the PO410 code for both sides. It is an annoyance I would like to fix.
Make sure your Air Pump is working at cold start-up by disconnecting the two hose sections under the hood next to the driver side fender just above the driver tire. There is a splice there that you can take apart. Start car after disconnecting hoses. Check under hood to see if air is blowing through hose.
02-25-2014, 05:32 PM
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If you would like to check that the exhaust makes a vacuum through the secondary air ports on the exhaust during idle..... remove the metal pipes at the flange on the exhaust manifold and start the car. Hold a strip of paper above the hole where the pipe was ..... and it will try to suck the paper in.
