Secondary Air Injection Issues

[mike.lloyd]

Thought I'd add these notes on recent DYI repair that might help someone. The cheaper non-Piersburg aftermarket pump that I bought from autowarehouse.com works but is not identical to the OEM Piersburg pump in two respects.

First - Instead of having 3 'male' threaded bolts attached to rubber mounts that attach to the housing, it has 3 threaded "female" receiver holes. I used 3 1" Metric 8 (1.25 threads) bolts and some rubber washer spacers to attach it and provide some dampening. About $4 at Home Depot.

Second - The electrical connection is at a different angle. The aftermarket plug is perpendicular to pump instead of parallel as was the OEM. Wiring was very tight on daughter's beetle. The electrical harness that plugs into the pump was 180 degrees off which initially did not allow enough clearance to install and blocks the dipstick tube. You can pop off the casing to the electrical harness and rotate it 180 degrees and re-close the casing. This gives you the necessary clearance to install and not interfere with the dipstick.

I hope this post helps someone else avoid some of the cussing that my neighbors had to endure.

[Oldbugman]

I too am working on the dreaded P0411 code. So far I have found the system works exactly as it should with no faults that I can detect.

Checks so far.

Vacumn hoses all ok swapped them out with silicone hose when I had a similar issue about a year ago.

Solenoid clicks when voltage applied and also allows vacumn to be applied when energized.

SAIP blows like a leaf blower with output hose disonnected.

Try to blow through Output hose into combi valve lot of resistance, apply vacumn to combi valve no resistance.

I can find no hoses related to this system or any other system that appear to be leaking. Vacumn or pressure leaks.

I am now thinking the ports that the combi valve mounts up to are partially block causing insufficent airflow. I will be checking that as soon as I get the needed gaskets. Prior to removal of combi valve I will check and see if it holds vacumn.

The part that puzzles me the most about this is the combi valve is essentially your EGR valve, which I can find no information on.

Last but not least if the combi valve passes my final check and the ports are free and clear then my next step will be to replace the rear O2 sensor. From what I have read this is where the ECM obtains it's information as to wether or not the system is functioning properly.

The saga continues........

[mike.lloyd]

Let us know if you figure it out. I was convinced it was the secondary air injection pump on my daughter's 1.8T 2003 beetle. I gerry rigged and wired the old pump to the battery and could never get it to work. Replaced. Two weeks later - P0411 code has reappeared. Love the daughter, but truly beginning to hate the car.

[FootScoot]

I had that P0411 code a few days ago, and it had been a recurring issue which was driving me crazy. I knew the pump was working because I could hear it upon cold starting. It would run for a few seconds then shut off. So I thought maybe the plastic hoses were bad, so I removed them, and checked, and they were fine. Reinstalled them no CEL for 3-4 days, then light has returned. I then retraced everything I had done, and found out I had not snapped the hose to air box on both sides, so I removed it and reinstalled and listened for the clicks, took a bit to get the second click, as there isn't much room there, but no more CEL for 2 weeks now.

[Oldbugman]

Well my CEL went out yesterday indicating to me that whatever the issue was I apparently corrected. Kinda aggravating not knowing what the exact cause of the problem was. But happy to know it's fixed.

[esse10]

Originally Posted by cwhitjr

it's essentially a fan. You can just hook up power to it. When mine went bad all it did was whine like a jet engine. Picked up one from the local junkyard ran power to it. It should blow steady and relatively quiet.

That's what mine is doing now. Did you take it apart to see if you could repair it or lube the bearings if it has any? then assemble with screws? I will take mine apart this weekend if it's a cool day, hate to work on my cars when it's 90+ degrees outside.

[Oldbugman]

Originally Posted by Oldbugman

Well my CEL went out yesterday indicating to me that whatever the issue was I apparently corrected. Kinda aggravating not knowing what the exact cause of the problem was. But happy to know it's fixed.

Well once again today my CEL came back on the dreaded PO411 code once again. Exactly 1 month to the day. This time I rapped on the solenoid then cleared the code, so far so good. Seems I may have found the answer to my particular cause being a intermittent failure of the solenoid. Time will tell........

[polycat33]

Originally Posted by Oldbugman

Well once again today my CEL came back on the dreaded PO411 code once again. Exactly 1 month to the day. This time I rapped on the solenoid then cleared the code, so far so good. Seems I may have found the answer to my particular cause being a intermittent failure of the solenoid. Time will tell........

It takes a bit of time for the light to come back on. Even if the system is getting no air into it from the pump, it'll still run for maybe a day without the light coming on, in my experience. Not to say that'll happen to you, just a heads up to not get your hopes up until you run with it clear for a few days.

[billymade]

I had this issue and it was resolved by replacing the kombi valve; this thing was expensive and when testing seemed to be ok (it would go up and down but I think it was binding)... a new one fixed the issue. I also eneded up replacing some of the hoses that went to the kombi valve; they were brittle and were cracking when I was doing the repair; I also replaced the air pump motor mounts that had broken.