Bad Air Pump & SAS Valve - PO410 - Secondary Air

[Guest Guest]

obdII code PO410 what does this mean

[MadeInJapan]

Secondary Air Injection System.

Most likely your secondary air pump (under the battery) is not coming on. It comes on when you first start your car to pump heated air into the air-intake.

[pfeener]

Other way around, the pump takes air from the air box and pumps it into the exhaust to burn the off the gas from the rich mixture that's present when the car is running cold.

[Figawi]

my inspection station just called to tell me that my 850 won't pass because of a secondary air injection fault in the OBDII. Sounds to me like i have a bad air pump? this is for a 97 850GLT so it DOES have an air pump i believe. hmmm. would the CEL turn on if i unplugged the hose that goes from the air box to the air pump so I could put a cold air intake in during the summer?

this sucks. i'll have to search more to fix this problem before Kevin tells me to do so.

[Figawi]

ok it is this code that is faulting: PO410

could this be caused by a bad hose from the air pump or is it strictly electronic that would trip that code?

[the underlørd]

ok it is this code that is faulting: PO410

could this be caused by a bad hose from the air pump or is it strictly electronic that would trip that code?

good q.

I have the same problem.

[Figawi]

buump.

[Figawi]

well i reset my codes and drove the car around for a while. code hasn't come back yet. i think it might have been tripped when i replaced my air box with a cone filter. now that its back to stock the code is gone. don't know of it the two are related.

[pfeener]

The code will come back when the monitors routines run. Probably within the next few days. If you have a bad air pump or a SAS valve, it won't usually set the CEL until the secondary air monitor runs to test that system after a reset of the system.

The secondary air is a very simple system. When the electronics module calls for secondary air (usually when you start the car cold or sometimes when you stop at a light after you've been driving for a while) it sets a ground to pick the air pump relay and turns on the pump and sets a ground to pick another relay to apply vacuum to the SAS valve and open it. The air pump takes fresh air from the hose coming from the air box and pumps it up to the SAS valve and into the exhaust system, which will reburn some of the fuel still in the exhaust gases and the electronics will see a leaner condition coming back from the O2 sensor. If it doesn't see this leaner condition it assumes the secondary air system isn't working and sets the CEL but only after several failed attempts. If you have a code reader you will see the PO410 code in a pending state before it fails enough times to turn on the CEL.

The hose from the air box just supplies clean air to the system. You could disconnect it and the seconary air system will still work and won't set a CEL. If you disconnect the other hose going to the SAS valve a CEL will be set but not until the electronics has detected a failure on several tries.

It's a pretty easy system to troubleshoot. If the CEL comes back and you want to do it yourself. Answer back and I'll give you the procedures. You can also do a search and get troubleshooting information as well.

[Figawi]

The code will come back when the monitors routines run. Probably within the next few days. If you have a bad air pump or a SAS valve, it won't usually set the CEL until the secondary air monitor runs to test that system after a reset of the system.

The secondary air is a very simple system. When the electronics module calls for secondary air (usually when you start the car cold or sometimes when you stop at a light after you've been driving for a while) it sets a ground to pick the air pump relay and turns on the pump and sets a ground to pick another relay to apply vacuum to the SAS valve and open it. The air pump takes fresh air from the hose coming from the air box and pumps it up to the SAS valve and into the exhaust system, which will reburn some of the fuel still in the exhaust gases and the electronics will see a leaner condition coming back from the O2 sensor. If it doesn't see this leaner condition it assumes the secondary air system isn't working and sets the CEL but only after several failed attempts. If you have a code reader you will see the PO410 code in a pending state before it fails enough times to turn on the CEL.

The hose from the air box just supplies clean air to the system. You could disconnect it and the seconary air system will still work and won't set a CEL. If you disconnect the other hose going to the SAS valve a CEL will be set but not until the electronics has detected a failure on several tries.

It's a pretty easy system to troubleshoot. If the CEL comes back and you want to do it yourself. Answer back and I'll give you the procedures. You can also do a search and get troubleshooting information as well.

thanks i will check back with you in a few days. as of right now my obii says i have a bad 02 sensor now and the car is running too rich wtf.

[pfeener]

Probably correct. I would change out the O2 sensor and see if that clears the code. I've never verified it first hand, but I could see where a bad O2 sensor might set a secondary air code as well. The O2 sensor provides the feedback to the ECM that verifies the secondary air system is working.

The O2 sensors are good for about 100K miles and that's about it. If you are over or near that milage on the sensors, it's time anyway.

[Figawi]

Probably correct. I would change out the O2 sensor and see if that clears the code. I've never verified it first hand, but I could see where a bad O2 sensor might set a secondary air code as well. The O2 sensor provides the feedback to the ECM that verifies the secondary air system is working.

The O2 sensors are good for about 100K miles and that's about it. If you are over or near that milage on the sensors, it's time anyway.

Bad News. You were right

Yesturday morning I had NO CODES come up in the OBDII scan. Car drives wonderfully. Last night, the CEL comes on!!! Code P0410 is back The car still drives wonderfully so I am going to rule out the O2 sensor for now and replace the Air Pump.

[pfeener]

I think you are correct in your thinking.

There's two components that typically fail; the pump and the SAS valve. To test the pump, I would remove it from the car and see if it's full of water. If it isn't full of water, apply 12V across the input terminals (watch the polarity, it's marked in very small print on the housing) and the pump should spin up and blow air. The SAS valve is mounted on the exhaust manifold and is very simple. No vacuum applied it's closed and with vacuum it's open. You can leave it in place if you want and attach a hose where the hose from the pump plugs in. You shouldn't be able to blow through the hose with no vacuum applied and you should be able to blow through the hose with vacuum applied. Many times both the valve and the pump are bad because the SAS valve has leaked and lets exhaust gas into the pump which condenses and fills the pump with water.

I did my pump a while ago and I used a VW pump I bought off ebay for $45. I looked today and there's a couple of pumps up there that will work. One is brand new. The instructions for converting it over can be found on matthewsvolvo site in the repair section.

[Figawi]

do you know if one of a x70 or another year 850 would fit my car? its a 97 850 glt. i might just swap it and see.

[pfeener]

Looking on FCPGroton.com; the pumps for 93-95, 96-97 and the S70s are different. The 96 and 97 850 and the S70 look very similar and look like they could be adapted.

Here's the link for the VW pump replacement procedure.

http://www.___.com/air_pump_...acement_850.php

Also check out ebay item number 8065693999. That pump will fit with some minor modification. Buying a used Volvo pump can be problematic because so many of them fail. The VWs use the same pump (made by Pierburg) but have a different check valve system and they don't fail.