What he said 👍

 

What he said 3, mine would come on when it would rain. Drove me crazy...

 

Thank you. Folks, keep in mind I have an SRT6, so the air pump location is on the drivers fender well. I am not sure where the ground terminal is, but my guess is it is the grouping of wires in the corner of the below picture. I removed and cleaned the connectors and terminal. Reset codes. The next day in the morning the air pump went on as usual. When I got to work, there was the P0410 code pending.

 

The the repair manual holds many secrets, 😉 that with diligent study will lead you on the path of enlightenment.

 

Folks, I am still having the P0410 check engine. A quick overview = 2005 SRT6 coupe, runs great, 86k miles:



1) I started getting the P0410 code. RCM rebuilt by tighed1, new relays and horny mod. After I put in the rebuilt RCM, the 40A fuse blew as soon as I turned on the car from a cold start.
2) Replaced the 40A fuse on the RCM and with a voltmeter measured 14V or so on the connector going to the secondary air pump. So I figure my air pump needs replacement.
3) Replaced the air pump from K-Parts. Emission Smog Air Pump For Mercedes-Benz SLK32 AMG V6 3.2L S63 CL63 AMG V8 6.3L. Fit like a glove.
4) Now when I start the car cold I hear the air pump turn on for the first 30 seconds or so. I figure I fixed it, but wrong. After a day of driving, the P0410 comes back. I clear codes. Still comes back after a few days.
5) I replaced the blue air check valve from AutohausAB, (0021408460, Vacuum Check Valve). I clear codes. The air flow from the blue check valve seems fine. I follow the airline to the top of the blower and it also seems clear (not clogged).
6) After a few days of driving, I get the P0410.
7) Checked the ground connections on the SRT6 air pump location on the driver’s fender well. Disconnected and cleaned the battery terminals, then reconnected.
8) After a few days of driving, I get the P0410.
9) Replaced the Maybach EGR change over valve 0025401497, also cleaned the electrical connections. .
10) After a few days of driving, I get the P0410.
11) Removed the RCM and inspected the soldering connections just to make sure tighed1 didn’t forget anything. The connections look good and the relay contacts are good. I have pics. I also disconnected the large ground terminal connection to the frame from the negative battery terminal and cleaned the connection, then reconnected.
12) After a few days of driving, I get the P0410.


In summary = I replaced the RCM, Air Pump, Blue Check Valve, EGR valve. Plus checked and cleaned battery terminals and various ground hub terminals.



I have not spent much to try to fix this issue, maybe only $225. Most of my time has just been staring at the engine bay looking for ground points. Car still runs great, but one of these days I’m gonna need to pass emissions testing in NY state. I welcome additional advice from the forum.

 

I was having a similar problem. Every time it would rain the dang code got threw. PPPPed me off an drove me crazy. Every time I went looking , the locks on the RCM box were unlocked. I thought maybe , I didn't lock them, an it was a coincidence. Finally, I made sure the seal was intact, an it locked , this time for sure. I haven't had a problem sense. Make sure the fan is running an the seal is secure. That solved my problem.

 

I went through the exact same issues as you this summer, except I purchased a new RCM from the MB dealer and had the air pump rebuild by local shop that does starters/alternators etc.. only thing I did different was not replacing my EGR valve.

Air pump would run every morning like clockwork, tested with the engine cold by applying voltage to pump and actuator and could feel air blowing out the exhaust.

Two days later, the code would comeback.

Then, every morning for a week - before starting the engine, I would switch on the rear window defroster and what-do-you-know, the problem went away and I passed CA smog.

I'm guessing that the ECU monitor for the secondary air pump would see enough current draw to calculate that the air pump was switching on.

Been about 3 months now without using the rear window defroster trick and no issues.

Hope this helps.

 

Or make you doubt your sanity.

 

13) I tried a few different variations of turning on the Rear Window defrost at start up: Turned on the defroster before start and turned off at the end of the first air pump cycle. Turned on the defroster before start and left it on. Each case the P0410 code would appear.



14) Figuring that the issue may be resolved with additional ground, I added an additional 16 gauge ground wire to the ground terminal of the air pump directly to the negative terminal of the battery. This was done be stripping ½ inch of insulation from the ground wire near the pump (without cutting the original wire) and taping in an additional wire by use of wire clamps. Note the battery is only 2 years old. Still no luck. After a few days of driving, I get the P0410.


I think I’ve run out of ideas. The forum has been a great help giving me tips so far and I thank you, but I fear that this issue might require professional help. Since I live in Ithaca, NY, I am hours away from any Mercedes dealer. Not sure what I will do next.

 

Got me stumped.
For the cost of return postage I'll go over your RCM again if you want.

 

I think that it is possible that the air is not getting into the exhaust, too little air is being blown into the holes in the block that go to the exhaust. These channels can get blocked and may need cleaning out.
That is what I have read, you have to check that the air is at least getting to the block first.
The cat sensors measure oxygen, too little and they set the code, or so I have read.

 

I agree with 180, the feedback system is not getting the correct signal that it requires so now all you have to do is figure out what is preventing it. Do a little more study on how the EGR system works. If all else fails Google it 😉

 

See Waldigs post from today. CLICK

 

Woody's post helped me understand how to better diagnose the issue I am having. I started the car this morning and found that the air pump valves not only did NOT have vacuum, but there was actually air blowing out on the vacuum lines. I tracked it down to the passenger side valve. I was able to connect the air pump directly to the battery to monitor air flow and found that with the air pump on there was air flowing out of the top vacuum line. I inspected the valve and compared it to the drivers side value and it appears the seal is broken. Picture below. Look inside the larger opening and you can see a gasket. So, I think my next step is to purchase a new air valve. AMG a1121400260. So far, I only see this part number on EBAY. I'd rather buy a new one.


As of 9/18/2017 = the problem is FIXED!. Thanks to the forum.

 

This part rarely fails so with 80+k on the clock I would say get a used one from a low mileage car and save the cash.

 

I reviewed my videos and saw that they were the same??????????????? durn

The posting was changed and the first video is here:


Makes more sense when you have all the info - correctly, Woody''

Sorry for confusion.WW

 

Hey everyone, been reading all of these great posts and did some basic troubleshooting. I too am have the P0410 code. If I connect a voltmeter to the plug that goes to the pump, I get nothing at all when the car is started. Should there be some voltage taking place there? Also, if I put 12v to the terminals on the motor itself, it just makes a buzzing noise, doesn't blow. Can someone guide me to what I should do next? I suspect the pump is shot so I'm going to replace it, but not having any voltage appear on those wires concerns me a little. I haven't taken out the relay yet to check it, figured if the pump wasn't working, no further troubleshooting until I resolved that. Thanks!

 

Air pump is controlled by a relay inside the RCM which is in a black box over by the battery, very common problem, do yourself a favor and just buy a new RCM and send the old one to tighed1 for refurbishing I think he charges about 30 bucks plus shipping both ways, when you get it back put it in the glove box for a spare along with a new crank position sensor. Use the search bar and type in RCM repair, everything you need to know already has been discussed numerous times in many many posts. 👍. Part # 170 545 03 05. Shop around online they range in price four brand new anywhere from $145 to $225 on the internet. If you go to your local Mercedes Benz dealer it's going to cost you $225.

 

If the motor has broken and does not turn then it is possible that the fuse for it that is on the RCM has blown. It could have blown because of the power called for when it would not operate. Also look at the contacts on the relays to see if any are burnt, if they are burnt they should be replaced.
While you are at it check the solder joints shown in the RCM repair thread.
RCM repair. CLICK

 

I have learned that a spare RCM is a good investment for a multitude of crossfire woes. FYI, Rock Auto has them listed as Standard Motor Products part #RY1562 for $130.
I was surprised when I received it that it is actually the OEM part just repackaged by SMP
Have I ever said this is a great forum