supersam

Hey Everyone, I have searched all throughout google, as well as scoured the forums to see if anyone had this issue. I'm the car nut in my family, and my brothers 2005 D3 A8L will not set the Secondary Air Monitor ever since I replaced his battery over a month ago.

We currently swapped cars, as my commute is about 80 miles each way per day; and I have put over 400 miles on this car and the secondary air monitor will not set. Every other monitor is ready, there are no fault codes, and here is California, every monitor must be set with the exception of Evap to pass smog. There aren't even pending codes.

I was thinking that maybe the secondary air pump wasn't connected; but it is, and i figured it would trip a code if the pump wasn't working, or if it were inefficient. I found some procedures for setting monitors and followed them to no avail. If anyone can chime in, or if anyone had this issue before, please please please comment.

BTW, there is no performance issues with this car, it drives great.

richard-tx

If it were mine, I would take it to the dealer and have them do the smog inspection. Tell the service writer nothing and then see what they say.

the_duke

When you say "no codes" I'm assuming you used a generic scanner. A VCDS scan will tell you why readiness is not setting.

MP4.2+6.0

+1. Need VCDS scan, not just code reader. From experience w/ D3 W12, the readiness codes reset driving routine stuff are hit and miss. The secondary air ones also need two full cold-hot-cold driving cycles and it is very difficult to simulate those, from personal experience. Some others (EVAP?) also require very specific revs held for certain periods, which is hard to do parked. Some driving loops can help, but depending on which test it is, it takes different revs. Every code clear of course resets readiness codes too, and means basically two more days/cold-hot-cold of driving cycles to get them to read pass if all in order.

Net, need a quality scan, not just code reader. Battery replace also should not have affected it. On SAI specifically, you should be checking air pump to see that it actually functions, making sure air lines aren't worn or kinked (including suction line from airbox area), and any vacuum hoses driving the combi valves are in order. Issue typically one of those, or an occasional bad combi valve.

richard-tx

Now you know why it is best to take it to the dealer to have the inspection done. They know all the subtleties that need to be done to pass the vehicle.

03_AR_CO

With VCDS you can also run a diagnostic procedure (it maybe the set readiness option, not sure as my VCDS is not hooked up to my car at this time, so going from failing memory) on the 4.2 it steps you through every engine component. Not an available script on the 1.8TT or the W12, but it is there for the 2.7, and the 4.2 from personal experience. Soooo, VCDS or the dealer would be your choice.

supersam

Wow, Thanks for all the responses. I set this thread to notify me through email, but none ever came in. Glad I checked in; thanks for all the great advice.

So, just to give a little background on myself..... I am a mechanical engineer by education, and have done just about everything there is to do on a mercedes (which is what I have driven for the last 8 years). I do all my own work, and have a pretty nice tool setup, including a Snapon Modis, Launch GDS, and then mercedes Specific dealer diagnostic tool (STAR).

Being that the audi is not mine, I really don't want to buy VCDS, unless ofcourse my multiplexer from my mercedes would be compatible with VCDS, but I highly doubt this.

I did a lot of reading, and get conflicting information on VCDS and forcing a Secondary air monitor test; some say it is possible for the d3, others swear it's not. BTW, i left the house this morning at 6am and it was about 55 degrees outside; started the car and let it idle for 2 1/2 minutes before going on my way. Did the same on way home; and you could definitely hear the vacuum pump; just to verify, prior to leaving work, I crawled under the car and disconnected the outlet pipe and it is blowing really strong, so i know it works.

I checked all the pipes, and also checked the rubber hoses from the SAI, and by checking, I mean pulling them, blowing into them, and listening for leaks...none; and they are not brittle as i would have imagined them to be.

Car now has close to 600 miles of driving, and the secondary air is still not reset. I'm going to continue to think this through; I called the audi dealership near me, and unfortunately, they are booking appointments 2 weeks out, and thats not going to work for me. Does anyone locally by chance have VCDS? I'd be willing to go anywhere in the S.F Bay area, and will gladly pay for your time... I've also been told that I'm a pretty cool guy, so you might even make a good friend

MP4.2+6.0

Given what you say you checked, faltering combi valve is probably most likely guess now. They don't fail often, but still can. But again with VCDS you would see from codes immediately which side ("bank") it is. One on each side, so still guessing even at that.

I also don't know on D3 4.2 if there is a vacuum solenoid switch in the vacuum hoses that ran the valves, or if still set up that way. My C5 2000 A6 4.2 had that, but my D3 W12 had no vacuum lines and relied only on the pump air pressure to move the combi valves functionally. Anyway, if there is a vacuum related switch in line with the hoses, check it carefully. On my C5, everything around that switch was problematic, particularly the the vacuum hoses that would constantly bake from the motor heat.

Also as an idea, take a piece of new vacuum hose (assuming it is relevant to set up) and use it to test combi valves w/ motor off. Just disconnect factory hose and attach yours. Suck on it and see if it holds vacuum and maybe you feel or hear it moving internally. Obviously if it doesn't hold vacuum it is blown. Problem right now is there are two of them, they are somewhat a hassle to take off, and cost $, and it isn't for sure at all those are the issue. One other thing I did at one point is take air hose off inlet to each combi valve and shoot some brake cleaner directly into it in case it had some mechanical issue. Ultimately mine turned out to be bad air pump, together with kinked intake hose with water pooled in it at bottom of air box; W12 has two so noticing only one was out is more difficult just listening for it.

richard-tx

Sam,

PM sent.

rich

supersam

@ Richard; Thanks for the PM, I pm'd you back.

@Mp4.2: Good advice. i will check into this. The drivers side combo hose is easy to get to so I may start off with that and hopefully get lucky. The passenger side is buried behind a bunch of stuff; but great advice. I will try this.

An idea crossed my mind today, and that was to tap into the secondary air power, and leave it running in the morning for longer than usual while monitoring my IM readiness; maybe it just needs to stay on for a little longer to get it set. Any thoughts on this?

Again, thank you for everyone who has helped. If anyone has a 63 AMG mercedes and is stuck on something, i'm your guy. I've rebuilt my motor more than once from screwing around with a supercharger and tune LOL>