Recently I've noticed my secondary air pump has been throwing a code... I can quickly clear it with the DashDaq but it comes back roughly once every two weeks. Secondary pump functions as normal, although it's sounding "rough" for lack of a better word.

 

Replacing the pump itself worked for me. I would check the filter on the pump though. Just be careful John it's very brittle foam.

 

Just an update,

I got hold of tighed who is trying a relay fix for the pump on a different RCM. I'll get back to him this coming week. I did grab another RCM in the meantime and the secondary pump is up and running.

Thanks
Kolme

 

What was the problem?
Just so I am prepared if I ever have to do it.

 

Bad news.

Originally on a cold start the air pump did come on with the new RCM, as it did originally after I did the quick fix on the first RCM, but the CEL has returned and the pump isn't turning on again. Sounds like it's now the pump itself that needs replacing. And I likely now have an extra RCM. :/

Also I'll mention that the pump when it was on sounded a bit rough and whiney as it had been doing for the last month or so.

Kolme

 

http://www.carparts.com/details/Merc...FY1r7AodAmQA-Q

Do you think I could modify the hose or housing to make this pump work? It should have the correct specs being a c32 pump, it's just that the nozzle faces opposite of the original.

 

Sorry to "necro" this thread, but I wanted to detail my final solution to this whole thing so that others might benefit from it.

1. Tighed was able to put on a new relay which fixed the relay issue, he rocks. The extra RCM from ebay that I had also would have worked.

2. The secondary air pump did indeed burn out. Even though I had kept it disconnected, it seems that the damage was done and only after a few hits with a hand would it even make a sound. The dealership quoted me 1300 bucks for one.... But on ebay I soon realized our pump is synonymous with many other Mercedes pumps, at about 250-400 bucks used (note that this applies for the SRT6, the N/A uses a different pump I believe.)

3. Instead of buying one of these, I contacted an ebay user named rostykf who remanufactures many of the Mercedes pumps which are similar to ours (http://m.ebay.com/itm/261516532760?txnId=1441230489016 He said that I could ship mine to him and he would see if he could fix it for only 109 bucks + shipping (he said it was free if it wouldn't work). Very quickly after receiving it, he detailed what was wrong and offered a lot of great information about the cause (the relay), he assured me he could remanufacture it and sent another one my way to cut down on the wait time. After installation, the newly remanufactured pump purred like an oem kitten and the CEL is now gone. You can tell he does quality work, the pump looked practically new. It's hard to say how long this pump will last, but for 109 dollars it's an excellent alternative to buying an old pump for much more. (Once again note that I have an srt6 and I believe the n/a pump is different and therefore may not apply here)

I hope this helps someone!

Kolme

 

Thanks for the follow up, it is most welcome as many posters get their answer and then do not bother to reply with the outcome. This especially problematic when a new problem is discussed and we are left with no outcome.