I had this problem, its the MAF sensor. Its a very expensive part if you goto the dealer around $400. There is a cheap fix though. Get some MAF cleaner from a auto parts store or the dealer, take the MAF off and spray down the eliment ( silver wire looking thing) inside the tube. Keep in mind this is only a temp fix, mine has lasted a couple of months so far. Some where i have pictures, if i can find them i will post for you.

 

try this search

morning starts latley

my pix are there

 

I am unable to get to that thread ... any pictures of the MAF and of the air pump/connector/fuse would be helpful.
Really didnt want to start the weekend this way!

Most of the other posts say that it has something to do with the airpump. when I first turn the ignition on, there is a slight sound which i thought was the starting of the fuel pump, but im guessing it is the air pump, it still seemed to turn on when i started it last.

Another question - the autozone people won't reset my check engine light because they want me to take it to the mechanic and pay for it. Would removing the battery reset it?

Thanks a bunch!

 

MAF pix

 

live or die, please email me pics - salmansaif@gmail.com . I appreciate it.

 

I dont see any pics on this page - am i doing something wrong?

 

More MAF pix
Hope this helps

 

I can see them now. Thanks a bunch!

Do you think removing the battery would reset the CEL?

 

No, IMO the best way to clear is with a code reader. Keep looking some place's will loan you the reader and then you can clear the code. If you try and clear by pulling the battery you will need your radio code.

 

By the way, Welcome to the forum. Please update your profile with car info.:thumbsup:

 

where would I find the radio code? I bought it used ,but I am the second owner, i do have the owner's manual etc.
Regardless, would removing the battery take care of the dumb CEL?

Thanks again!

 

Radio Coed



Not meaning to jump in here too late but I just bought my SLK less than two weeks ago, I am the 2nd owner as well. I read in the manual about the radio code and frantically searched my paper work for something with the 5 digit code on it. Turns out in my case that it is written on the inside cover of the owners manual. Check your stuff and see if there is a 5 digit code written someplace.. beats having to pull the head unit out if you dont have to!

 

Also, I live in Maryland and the temp dropped considerably the last 3 days and it has been raining (I dont have a garage ) ... do you think this has a role to play in this issue ?

 

The temp. has nothing to do with the MAF going bad. 9 time out of ten its just dirty and needs to be cleaned. If you don't have the radio code you can pull the radio , get the serial number from the back and the dealer will get the code for you. The codes are stored in the computer so pulling the battery cable probaley won't work.

 

got it.
so even after I clean the MAF, I still will have to go to someone or get the scanner myself and reset the CEL , correct? Merely cleaning the MAF won't reset the light by itself ?

 

Thats correct, cleaning won't clear the code, you will have to reset it.

 

Pulling the battery can cause other issues as well. A power surge can fry the electronics including all the dash board lights. Check the posts on that as well.

 

When i changed my multi switch i had to disconect the battery because of the airbag, when i re-connected the battery i lost two dash lights.

 

Don't disconnect the battery. Go to Autozone -- they can pull the codes and then clear them...for free.

And clean your MAF. As soon as it stops raining!

 

the attitude boys at autozone gave me the code, but wont reset it saying they cannot . its agianst their policy because dealerships want to sue them for clearing codes so dealerships can charge for that service (b.s? )

 

Yah, thats what they told me, then they said if i wanted to clear the code i could buy the unit for myself.

 

Scanner for codes

I went to my Local Schucks Auto Supply and they will loan you a reader, Just plug it in, do the scan and then hit erase code afer you are done. This resets your computer.

After I did this the ck engine light was turned off and the scan came up clean saying there was nothing in my computer at this time.

 

hi guys, happy new year.
well my CEL is back again!!! its the same code ( i bought an OBDII scanner last time it came on). I reset it again last week and after driving about 20 miles its on again. I guess I shouldnt keep resetting it since there obviously is a problem...

so what does this mean ? A new year's trip to the stealership!?

Thanks!

 

P0410-Secondary Air Injection system fault

The dirty MAF is seconday effect.........the primary cause will probably be the Air Injection Check Valve if you have a US spec SLK

On US models this is used to heat up the O2 sensors and catalyst quickly after a cold start..... the supercharger delivers the air needed....normally-aspirated MB's have an air pump

A check valve under the Air Filter Box allows air to flow into your exhaust.......failure of this valve can cause MAF & O2 Sensor problems

A check of the connections to the controller under the front plastic engine cover is also worthwhile

Valve replacement recommended at 50K miles.......apparently these valves can rust through from exhaust heat due to malfunction....then you can get exhaust in the intake before the MAF.........

 

The dirty MAF is seconday effect.........the primary cause will probably be the Air Injection Check Valve if you have a US spec SLK

On US models this is used to heat up the O2 sensors and catalyst quickly after a cold start..... the supercharger delivers the air needed....normally-aspirated MB's have an air pump

A check valve under the Air Filter Box allows air to flow into your exhaust.......failure of this valve can cause MAF & O2 Sensor problems

A check of the connections to the controller under the front plastic engine cover is also worthwhile

Valve replacement recommended at 50K miles.......apparently these valves can rust through from exhaust heat due to malfunction....then you can get exhaust in the intake before the MAF.........

Great post! I have to agree with you. Exhaust gases leaking into the induction system upstream from the MAF cannot be a good thing.

I did mine today at 67,000 miles. Changed the valve and cleaned the MAF for good measure. Made a big difference. Operates correctly is the best way I can express it.

The valve was indeed bad. I could blow through it in both directions.

I had an easy time of it by getting the correct tool beforehand. I first removed the air cleaner box and then unbolted what I think is the heater water pump. I was able to then move it out of the way. I also removed the oil separator and used the opportunity to clean it. I then used a modified 27mm crowfoot wrench to loosen the valve. I used a 1/2" ratchet with a 4" extension. It came free fairly easily.

There is a Mercedes tool for it which is a special thin 27mm crowfoot but it was expensive. I found a generic one online for $5.00. I feared it would be too thick to fit in there and it was. So I spent about 20 minutes on the bench grinder and made it work. Do a google search on "27mm crowfoot" they are all over the place. Sorry for the quality of the pictures.

 

thanks, are those pretty simple DIY checks ? i am not a handy man by any means .. any more detail would also be apprecaited

 

Full diagnosis would involve reading Oxygen Sensor voltage output .............

Once per driving-cycle, on cold start, the air pump (S/C in this case) is activated for ~10sec.
Lambda factor should change to ~+25%(rich)​

Two consecutive failures => CEL & P0410​

................if this is way beyond your ability/knowledge then there are some simple checks that you can make before going to the Dealer

1.Carefully pull off front plastic engine cover
2.Visual check of connections to switchover valve
3.Visual check hoses and components as shown in bottom picture
4.If everything appears intact then the check valve should be replaced

............this may be best left to your Mechanic.....if you manage to locate the check valve using the pics above, then you may be able to assess what is needed in the way of ability & tools to R&R the valve....

The Dealer will probably charge for a DAS scan to confirm your DTS Code .....2-3 hrs labour .... and probably recommend a new MAF at Dealer price

An Independent MB Mechanic will probably accept your scan .....the check valve is not expensive....and he should have equipment to read the O2 sensor output to confirm correct operation of the Air Injection System after the repair....if a new MAF is recommended then you should be able to get one at much better than Dealer price using info on this Forum

Cheers

David

 

Hi,

Thanks! I wonder what tool did you use to remove that air check valve?

 

Some one posted earlier, 27mm ground thinner.

 

Thanks for that info. Interesting thing right now.....I'm on my third bottle of Techtron Chevron in the gas tank. Cleared the code last Saturday, been driving the car every day since, and the code has not come back on. Maybe just coincidence.

 

Anybody have the part number for the check valve? I need to replace mine.

 

002-140-68-60 got this off of my invoice. I paid $60.00 from the dealer