Secondary Air Injection Incorrect Flow (P0411) fix!

[benny_mech]

Since I see this question posted all the time, here's my fix. Please note that you may not have the same exact problem, but I'd start here.

Your car spits the ever popular P0411 error code, here's (probably) why.

Pull the front bumper/rad support.

Peek under the intake manifold. (Sorry for the dark picture).

The 4mm inside diameter vaccuum hose gets pinched between the lower intake manifold and the secondary air pump housing, flattening it over time.

Remove the combi valve from the cylinder head. It's the hose running from the solenoid valve to the combi valve.

Replace that hose with some plastic emissions tube from your friendly Autozone.

Has a smaller outside diameter, and won't get pinched.

Drink beers.

Note that if you have this style valve with the vac port out the top, your vac hose routing is probably much better, and won't get pinched. (From Bently).

For reference (from Bently).

The pinched hose gets a vac signal when the secondary air injection valve opens. It (should) in turn supply vaccuum to open the combi (shut off valve) to allow the air from the sai pump to flow into the cylinder head. When it gets pinched, the combi valve doesn't open, and the pump tries to blow air through a shut valve. My pump sounded like it had bad bearings because of the added load, but now it's so quiet I almost can't hear it.

Edit: Fixed picture links. Photobucket blows goats.


Modified by benny_mech at 11:00 PM 1-28-2008

[s4nit]

I have to check this out tommorw at work and print it. I just got the code on my car. Do you need to pull the bumper or can you see it if you jack up the car?

[benny_mech]

You have to get the combi valve all the way out to get at that hose. You might be able to do that by unbolting the front engine mount and jacking the engine up, but I'm not sure. It's actually a real pain to get at the bolt that holds it on even with the rad support out. It's best done with a ball end allen head driver (5mm I think). Pulling the front bumper/rad support only takes about 8 bolts, but there's a ton of wiring clips too. If you go the 'jack the engine' route, be sure your exhaust doesn't hit the underbody. If it does, you'll have to unbolt the cat -> downpipe connection, or start bending things.


Modified by benny_mech at 1:14 PM 5-25-2005

[SaucemanVR6]

really nice write-up.

i dealt with this SAIS crap a few months ago. first replaced the hose that goes from the pump to the combi valve. the hose was cracked in 2 places, plus the plastic connector for the combi valve was cracked as well. i was able to get to that by unbolting the top of the rad support and tilting it forward slightly.

after the code came back, i decided to check the vacuum lines and the line that you show as pinched was completely gone. i was able to get to the combi valve pretty easily by unbolting the front lower mount and jacking the engine up.

just a few other options that work as well.

SAIS is a big PITA for something that runs for such a short period of time.

btw, if you need to reset your readiness codes for inspection without having to drive the car around for a few days, i wrote a thread explaining how to do it with a vag-com in about 15 minutes:
http://forums.vwvortex.com/zerothread?id=1904536
might be useful to anyone that fixes this and has to go through emissions inspection that scans your obdII port.

[benny_mech]

Thanks! I wish I had yours a couple weeks ago. My readiness codes weren't setting and my tabs were expired. It turns out they will run the car on the rollers and use the sniffer if your codes aren't set (in Snohomish county, WA). Passed that way with flying colors.

[TR04gli]

OK - I'm bringing this thread back from the dead to add a few more useful bits of information to it after going through practically HELL to get this thing fixed on a 98 VR.

First of all - There are 3 components to the SAIS -

1) Secondary Air Inejction Pump - Expensive
2) Secondary Air Injection Valve aka Combi Valve aka Kombi Valve aka EGR Valve - Approx 200$ from http://www.worldimpex.com
( http://www.worldimpex.com/item...39722 )
3) Solenoid

I have part numbers for 2 and 3 for a 98 VR I can post Later.

While you have the car torn apart to the state shown in benny_mech's first pic I woud recommend getting at least 2 feet of vac tubing and replacing all the vac-tubing in this system. In my car there was a U shaped section that ran from the Intake to the Fuel Pressure Regulator that had a T fitting in the middle of this. Off the bottom of the T fitting was a line that went down to the solenoid, and a second line that came off of the solenoid that went to the Kombi Valve.
Bold for Emphasis On a 98 VR every last INCH of that vac tubing was crumbling in my finger tips. Do yourself a favor and replace ALL of it .

Secondly - Here's some helpful troubleshooting info...


This is a picture of the Kombi Valve. The black part connects to a plastic tube that connects to the actual Pump. The Left hand side shown in this picture attaches to a metal piece with an O-ring that inserts into your motor. The vac nipple (bottom right) should have Vac tubing attached to it.

To determine if you valve is bad remove it from the motor completely. Put your lips around the black section and blow. If air passes through the valve it is bad. Now find a source of vacuum (power brake bleeder, or temporarily steal the line coming off the bottom of that T fitting and have a buddy start the motor briefly). Put vacuum onto that nipple. With vacuum applied you should be able to blow through the Kombi valve with a minimum of difficulty. If you can blow through the valve with NO vac, or you cannot blow through the valve WITH vac then you probably have a bad valve. Prepare to spend 200+ $.

In my case all the vac tubing was basically destroyed. I opened up the motor, replaced it all, put it back together assuming that would fix it, and boom. Same code. I did not know how to check the valve at that point, so I did not think to check it.

I then had to open up the motor again, and check the valve. Turns out the valve was OK. replace the 11$ solenoid and boom! I was in business.

I dont have a good procedure for testing the pump if you do not have a vag-com. With VAG-COM Start the motor to idle. Open Controller, Engine. Open Basic-Settings. Block 160 will test the SAIS. Have a buddy stand by the front of the car. He/She shold be able to hear the SAIS Pump turn on for a short time and pump air. If what you hear sounds like a shop-vac your valve is staying closed. This could be because of a bad solenoid or a bad valve. This should be audible inside the car at idle (even with a loud exhaust). . I dont know what the other conditions will sound like.... this was the only condition my car experienced.

Edit: Last but not least - if you're dead-set on checking the 11$ solenoid before replacing it... let the car get cold. By the time you get it this far taken apart it should be more than sufficiently cold. Put the vac tubing that goes from the T fitting to solenoid in the right place. Attach a length of vac tubing to the solenoid on the nipple that should lead to the combi valve. Hold your thumb over the piece of vac tubing that should go to the Kombi valve and have a buddy start the car briefly (15-20 seconds). You should be able to feel vac on your thumb. If you cannot, disconnect the other piece of vac tubing and check for vac on the tubing coming from the T fitting. If there is vac on the T fitting, but none on the solenoid on cold start then your solenoid is malfunctioning.


Modified by Xanthazar at 10:21 PM 9-9-2005

[fastnetmail2]

Hi TR04gli,

Can you tell us which solenoid you replaced? I know someone else posted, but I want to make sure it's the same solenoid that you're talking about. I'm not sure if my car have two solenoid or one. thanks.

[gotissues68]

Excellent info. I'm fighting this right now myself. I've made several posts trying to figure it out. I took your info about using vagcom after having pulled my front end apart and replacing the tubing from the combi to solenoid and still was getting the code showing up and it indeeds sounds like a shop vac ... so I'm going to replace the combi and solenoid next.. figure might as well replace both while I'm in there. I see the link for the combi, if anyone can get the part # for the solenoid that'd be sweet

[TR04gli]

Quote, originally posted by gotissues68 »

Excellent info. I'm fighting this right now myself. I've made several posts trying to figure it out. I took your info about using vagcom after having pulled my front end apart and replacing the tubing from the combi to solenoid and still was getting the code showing up and it indeeds sounds like a shop vac ... so I'm going to replace the combi and solenoid next.. figure might as well replace both while I'm in there. I see the link for the combi, if anyone can get the part # for the solenoid that'd be sweet

Before you blow 200$ on the combi valve try the test of blowing thru it. If you can - with no vac to it - replace it. If you can't then apply vac to it. If you still cant blow thru it at that point - replace it. Otherwise save the cash and just replace the 11$ solenoid. I'll post a p/n tonight when I get back to my home comptuer where I've got it saved.

[Soren]

Just a tip guys, you can test every component without removing anything.

To do the 'blow' test on the combi, remove the breather hose from the airbox, cup your hands around it, and blow!

As an alternative to blowing, you can just listen through it with the engine running. Before SAIS kicks in, you wont hear anything through it. When it kicks on, if valve opens, you should hear lots of growling internal engine noises as well as feel the pump drawing air in.

Here is my basic procedure:
1. Ensure SAIS pump is coming on, if so move to #2, if not, check relays, fuses, then check fro voltage to pump. If all are good, it's probably pump. Prepare to be super bummed.

2. Test solenoid by replacing hose to combi with a length of hose so you can feel for vacuum with your finger when SAIS runs. If you feel vaccum, solenoid is good. If not, replace solenoid ($8-$15). If this doesn't work, move to step 3.

3. Do the blow test described way above. If nothing happens, you may have bad vac lines or combi. Replace all vac lines, but most importantly the one running to combi. If that doesn't work, you have a bad combi. Prepare to be slightly less bummed than if you had to replace the pump.

Final tip:
You don't need to take off the front end!
Just remove the plastic cover on top of the grille, unbolt the top bolt from front engine mount, jack engine up a few inches with block of wood to spread pressure. Remove dipstick tube for a little extra room. Use 5mm(?) ball end hex driver to remove combi bolt and yank that bastard out.

Modified by Soren at 2:18 PM 9-12-2005

[gotissues68]

Awesome, glad to know I can test it without pulling anything apart again Just so I'm clear on this. If I blow with the motor off into the airbox hose towards the combi I should NOT be able to blow into it correct?

[edit]
I think this should go into the DIY or be sticky'd since its a very common problem on the VR's and gets asked all the time and this is the most comprehensive info I think I've seen to date on it (including pics and everything)


Modified by gotissues68 at 7:07 PM 9-12-2005

[Vdubsolo]

I agree...Its seem if you have a VR with over 50,000 miles you might have a good chance that some sort of vacume tubbing has dryd out especially the one under the intake manifold...This is a excellent write up too Its forsure a PITA, but for like 1-3bucks worth of vac hose n few hours In the garage....problem fixed

[Soren]

I've gained so much knowledge through this forum over the 5 years I've been a member.. It feels really good every time I can contribute/give back to the community.

[JTestman]

Xanthazar, Soren,

Thanks for the info, its extremely helpful.

Just to be clear on the instructions, I blew through the breather hose from the airbox and Air passed freely, I cannot blow through combi valve unless its under vacuum.

Does this mean the pump is bad? I hear the pump activate when idling and using vag-com to test it.



Modified by JTestman at 6:22 AM 11-22-2005

[Surf Green]

A FYI about bad Combi Valves before you spend $$ on them.

My Combi Valve was stuck shut, giving me the code (Everything else checked fine, and I replaced the vac hoses anyway)

I removed the valve, filled it with Carb cleaner (from the output side, which was full of black guuk). Let it sit for a few minutes. Dumped, and repeat a few times.

I was able to hear the valve open/close with my handy "Mouth Vac" on the vaccume hose.

Reinstalled, and it's been working fine for the past 2 years. At the very least... if it gunks up again, I can fix it long enough to work if I get another Emissions test request.

[amitesh]

What does solenoid looks like? What is the part number of solenoid for 2001 Jetta 1.8 Turbo?

[gotissues68]

Just wanted to update everyone who has posted so far and for those who might need this thread later.

Following Soren's advice I went ahead and attempted to blow into the breather hose connecting the airbox to combi with the car off (so no vac) and wasn't able to blow so I know the valve ic closed. I then took a piece of tube and connected it to where the solenoid => combi connection normally goes. After verifying vacuum at the t fitting I then tested for vacuum on that section of hose and didn't feel anything perceptable. I then normalized everything and put it back the way its supposed to be (so assuming vacuum from the solenoid to combi) and attempted to blow through when the SAI pump kicked in and was unable to. So at this point I'm going to replace the solenoid first since I have no perceptable vac going from solenoid to combi.

Hopefully this works out! I'm been letting this code lay around for too long (over a year).. now I feel like I have a fighting chance For those who don't have a Vag Com, if you can fork over the money I highly recommend it, the directions here to cause the SAI pump to turn on even when the engine is warmed up are perfect and it makes trying to diagnose things go much faster

[Soren]

Good work! That sounds like it's the solenoid. Let us know how it goes...

If it's not, you'll need to get that vac line replaced. It is a pain to get at, but nothing too horrible...

Here is another test you can try:
-Start engine, disconnect breather hose to get an idea of how it sounds when valve is closed.
-Shut off engine.
-Disconnect solenoid vac hose from tee fitting.
-Disconnect combi vac hose from solenoid.
-Connect combi vac hose to tee fitting.
-Start engine.
-This should keep the combi open constantly, so give the breather hose a listen. If the valve is open as it should be, you should hear lots of noise through it. If not, then the vac line is probably the culprit (or the combi). At this stage you'll need to remove that combi to replace the vac line, the combi, or both.

[masonr]

just wondering if you could explain or agree with this quick overview of the use of these parts.

SAIR Pump - Pump warm air into the intake manifold via the combi
valve

SAIR Combi-Valve - Get warm air from the pump but only opens
when there is a vacuum from the solenoid

SAIR Solenoid - Get a vacuum (not sure from where) and the
vacuum of air opens the combi valve, which then allows the
pumped air to pass through the combi and go to the intake
manifold

thanks for the help, i have had the problem for about 6 months and just fell into this forum last night.....awesome work

[1bad16V]

Quote, originally posted by masonr »

just wondering if you could explain or agree with this quick overview of the use of these parts. SAIR Pump - Pump warm air into the intake manifold via the combi valve SAIR Combi-Valve - Get warm air from the pump but only opens when there is a vacuum from the solenoid SAIR Solenoid - Get a vacuum (not sure from where) and the vacuum of air opens the combi valve, which then allows the pumped air to pass through the combi and go to the intake manifold

Actually it should be:

SAIR Pump - Pumps fresh air into the exhaust manifold.

SAIR Combi-Valve - Controls flow of fresh air into the exhaust manifold when vacuum is applied

SAIR Solenoid - Controls the vacuum to the kombi valve, vacuum is sourced from the intake manifold.

The purpose behind the whole thing is to get extra oxygen into the exhaust stream to help heat the catylitic converter faster... that's it. The OBD expects to see a 'lean' condition from one of the O2 sensors when the pump runs... if it doesn't it trips the code.

[masonr]

well my car is regisering the code for the PO411 and P0140 (Oxygen sensor no activity detected bank 1 sensor 2). The oxygen sensors were just replaced. I don't think that the 2nd o2 sensor is bad because i erased the codes and it came back the code for the 2nd o2 sensor with low voltage.

i just got techtonics catalytic converter (high flow) hopefully this helps with the 02 sensor, however i am wondering if the po411 code is affecting the p0140 code. any ideas??

[evershadowed]

I need to smog my car and I am pretty sure it is the solenoid on the SAI system that is bad. I replaced it 4 years ago when I had problems with the SAI (along with the Kombi Valve). I ran a few tests and it seems to be the solenoid. Here's what I did.

Started the car with everything normalized and listened to the pump kick on (that is the good news), also listened to the breather hose that attaches to the air box. It sounded like a wet/dry vac. Once the pump turned off it just sounded like how the car normally runs. I then took the vac line from the T-fitting that generally runs to the solenoid and connected the Kombi Valve ->Solenoid line to it (the T-fitting, which had vacuum)...the breather hose then sounded completely different (which I am assuming both from useful deductive logic....and what others have said on this thread...that the Kombi is still working). Does this so far seem correct?

I assume in order to correctly check the solenoid I need to wait until the car cools (as I don't have a VAG.COM) and start it again to check the vac on the solenoid (the Kombi->Solenoid line). Is this correct?

Finally, I need to try and pass Smog soon and as others have noted, the F***ing SAI throws off everything (my mpg has dropped to 16/23 at best and I do have new plugs, brand new CARB cat, clean air filter, etc.)

So I am wondering this....can I just connect the T-fitting line that usually runs to the solenoid directly to the Kombi? I imagine this would mean the Kombi valve with be constantly open, yes? Will this do any harm to the Kombi, or anything else? Sorry I am vague on this last part but I am unclear as to whether the Kombi/EGR valve has any other purposes other for the SAI system to work. thanks for any guidance

[evershadowed]

also, has anyone noticed if the solenoid used (i believe N112) is used on the mkIV's? I have noticed every once in a great while you can find a newer compatible part that costs a fraction of the price. Thanks

[gotissues68]

Update!

I went and purchased the solenoid from the dealer today 8.25 woo-woo came home and dropped it in. I now have very noticeable vac going out towards the combi ... I normalized everything again and went ahead and ran vagcom to force the SAI system to test. It passed the first run, the second run passed and then on the 3rd run through failed.

I verified hoses and then swapped then around just to ensure I didn't do anything dumb and came up with the same results (failure).

So ... I zero'd out the ECU once again and forced the test with Vagcom and checked the breather hose coming off the airbox, could blow through it when the pump came on with known good vac.

I already have replaced the hose between the solenoid and combi. So now it looks like its combi replacement time (boo!)

Just so that its noted here.

Part #'s for all 3 components of the SAI system.

Solenoid 191 906 283 A

There was a VIN split on both the pump and combi so I'm providing all numbers, check with your dealer when you go to purchase.

Combi part #'s
021 131 101 <= earlier 95
021 131 101 A <= late 95 and above per the dealer. You can tell if this is the right part number if you have a "T" in the last eight numbers/letters of your VIN

SAI Pump #'s
078 906 601 E
021 959 253 B
021 959 253

Hope this helps! And I'll be sure to post back the results once I get the combi done!


Modified by gotissues68 at 3:52 AM 9-19-2005

[grateful1]

Wheres the solenoid located? I have read through this post a few times now and see it menationed, but I don't see any pics of it.

Can I change this without removing the front end or jacking up the engine?

I'd like to check this and the fuses and relays before I take the car apart.

[masonr]

just wondering where you got the solenoid valve for like $8.00. The dealer sells them for 80.

thanks, any help would be greatly appreciated

[ThatGuy]

[masonr]

also is the solenoid valve the same as the purge valve?? how about the EGR Solenoid?? thanks

http://www.discountvdubparts.c....html

this site has a purge valve under Air Intake but i wasn't sure if this was the same as the solenoid

i live in hawaii and everyone (the dealers) wants about 90. none of the car parts stores (napa, checkers, and so forth) have the part.

[jetdavdub]

what happens other than a CEL if you take this system out? I've read many different things. You guys would mostly know.

[jhayesvw]

Quote, originally posted by jetdavdub »

what happens other than a CEL if you take this system out? I've read many different things. You guys would mostly know.

the CEL will stay on forever.

[1VR62NV]

should have jus got rid of the SAI and plugged it

[jhayesvw]

Quote, originally posted by 1VR62NV »

should have jus got rid of the SAI and plugged it

its illegal to get rid of the sai.

also, many of us have to pass a scantool test for emissions. without the pump, you will definately fail.

[TR04gli]

Quote, originally posted by jhayesvw »

its illegal to get rid of the sai. also, many of us have to pass a scantool test for emissions. without the pump, you will definately fail.

True

Thats why I had to fix it - Scantool Emmissions.

Personally, based on what this system does I feel it is of dubious value anyway. <this is my opinion, feel free to disagree, but realize i dont really care what you think>

If I had been able to find any real info about fooling the sensors with a resistor filled black-box I would have gladly done that instead of fix the damned thing. I'm sure it will only break again in the future and next time the car will be old enough that regardless of OBD2 scan-tool tests it will be a cold-day in hell before I'm spending 500+ $ fixing a system that runs for 30 seconds a day. Damned hippies.

[gotissues68]

I agree in that I think the expense associated with this particular system which is prone to failure makes it very hard to not just ignore it or search for inventive ways to disable it. I'm all for helping emissions but not at nearly a 1k in parts costs alone. I can only imagine what it would cost if I went to the dealer or a shop and had them try and do this In the same breath though I'm also taking this as an opportunity to learn more about the workings of my car

[1VR62NV]

Quote, originally posted by jhayesvw »

also, many of us have to pass a scantool test for emissions. without the pump, you will definately fail.

in canada we dont have a scantool test but you can run resistors in line with the wires for the SAI and the engine will not bring up a CEL

this was a big help

Quote, originally posted by all-starr-me »

My Vr is in a 95 car, even though its a 98 engine, I don't have to get it scanned for inspection since the car is OBD 1. Any way here is what I could find on what resisters to use for it, I'm not sure who originally posted it, sorry. I may have to put some kind of load (23 ohms, 6 watts (big resistor)) on the wire to keep from getting a permanent CEL. The ECU switches the grounds for the Secondary Air Intake Valve (N112) and the Secondary Air Injection Pump Relay (J299). The ECU also looks for current flow on those circuits and will throw a CEL if they aren't there. I removed the switched contacts from the relay that drives the Secondary Air Pump Motor but left the coil part of the relay connected. It is relay 100 in the relay box under the hood. I wanted to replace the relay and the vacuum switch with resistors to clean it up but the resistor to replace the vacuum switch would have to be about 5 Watts (BIG). A couple of 1 watt resistors (60 ohms for the relay, 30 ohms for the valve) and put them in a convoluted tube Here is the final version of the Secondary Air Recirc system kluge. I used a 28 ohm 3 watt resistor for the Secondary Air Intake Valve (SAIV) and a 58 ohm 3 watt resistor for the Secondary Air Pump Relay. 1. Use the wire to the power side of the Secondary Air Pump Relay coil and connect it to one end of both resistors. 2. Connect the other end of the 58-ohm resistor to the wire from the ECU side of the Secondary Air Pump Relay coil. 3. Connect the other end of the 28-ohm resistor to the wire that goes from the SAIV to the ECU. After the pic I slid the larger convoluted tube over it and taped it up.