I've averted secondary air pump failure previously by carefully listening for the thing to turn on and off. The relay ultimately sticks, your pump runs until it ceases, and a $20 fix becomes $400+ fix. Anyway, the last relay installed is sticking. For the life of me, I can't find an online source for replacement. The last one I installed I sourced off a parts site. Now, I can't find any.

can anyone help with a source. 002 542 65 19.

Thnx

http://www.parts.com/oemcatalog/inde...1&SearchType=1

Ordered from the same location. It comes direct from a Mercedes Dealership.

Thnx. Already found that as well as this https://www.getmercedesparts.com/oem...des-parts.html

Must be affiliate sites. Anyway, thanks for the quick response. Whenever something on the 32 goes wrong this is the first place a look.

Funny thing is, I pulled over quickly unplugged the pump to stop it - it probably ran for several mins before I noticed it was still on. I killed the engine, pulled the relay, got a CEL. Put it all back together and after a few on/off cycles CEL disappeared and pump appears to be functioning normally. But I have no doubt it's another failed and/or failing relay. That is the weak link nn this chain plus, not so many peope would ***** about it if the pump didn't set you back a mortgage payment.

So te lesson for beginners, on a cold morning, before u start the car, pop the hood, then start the car and run around to front passengers side area. Locate the pump ( you should probably do this first and there are plenty threads that picture it as it shuts off in less than a minute), touch it, hear it, see it...listen for the distinct sound. Remember that sound, also remember the time period it runs for. I know by the time I back out of my garage, down driveway and reach end of street it usually turns off give or take 10 yards or so.

Then, every time you start the car listen for pump to shut on and off. If engine has been recently run, it won't kick on. If your pump is shot, u already know this because the bright CEL is starring into your inner soul and poisoning every second of your driving experience. Bottom line, giving a simple listen for a minute for the pump to go on and off will save you (and has saved me at least two) overly priced AMG specific secondary air pumps. With the sound of your engine, exhaust and whining wife and kids it's easy to miss so keep a keen ear. Wait one minute before cranking up your nsync, backstreet boys or Molly cieris CDs and safe yourself at least a $400 part. If you listen those albums, throw in an extra $200-300 as you damn sure aren't doing your own labor.

Is there a way to pull the fuse to get it to turn off? I am not sure this is what is happening, but this morning I turned my car off and still hear a pump running. It sounds like it is coming from the front of the engine. At first it was loud, but after 5 mins it is not as loud. Could it be the stuck relay or something else?

Disconnect the wire harness from pump or pull the relay - no noise you found where its coming. The pump is on the front right passengers side of the engiine compartment. Bottom line, that pump shouldn't run for 5 mins. It'll run for about a min on a cold start only. It is possible for the pump to continue to run with the car off. It's on a constantly hot circuit. I've seen it happen to my own car. Troubleshoot that chit before you burn the pump up.

Thanks, good information.

So far no more issues with the pump running longer then it should and no CEL light so I think the pump survived. Perhaps the relay was stuck for a bit? I will order a new relay to be safe.

Pete

20$ of prevention is worth 500$ of cure.

just unplug it, and plug it back when u smog ur car.

F'ing Secondary Air Injector. Mine seems to be working fine but is still throwing a damn CEL. If you watch the values in the Starr (or is it DAS) you can see the values drop as expected. Unfortunately they get close but do not hit the values needed to prevent the CEL turning on.

If you don't mind starring at the CEL every time u get in ur ride that is an option. Of course, if your CEL is on all the time because of the pump disconnect, you'll never no if you have a true issue that arises.

What codes u getting?

P0410 - Secondary Air Injector

I have replaced several of these on my C55. Its a **** poor design, and I refuse to pay for another one.

I have also replaced the pump but it was very clear the pump was going bad. You could hear the bearings and then it quit working.

The current pumps seems to work perfectly but still throws the CEL. I guess it is possible that the pump is getting weak (although I do not think this is the problem). I am going to replace the pump to eliminate this as a possibility.

If it was not having to pass emissions I would just chuck the air pump out the window.