Sec Air Inject Malfunction - Page 2 - Mercedes-Benz Forum

Reply
 
LinkBack Thread Tools Display Modes
post #11 of 26 (permalink) Old 08-09-2010, 12:58 AM Thread Starter
BenzWorld Junior Member
 
Date registered: Aug 2010
Vehicle: 1999 ML320
Location: Saratoga, CA
Posts: 34
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
(Thread Starter)
'eric' and 'jsap' -- Thanks for the advise. It appears that the 'switchover' valve is a simple electrically operated vacuum switch. I can easily work on electrical and vacuum systems. I did some more research and now pretty much understand the system. It injects air into the exhaust for up to 90 seconds once the engine is started and certain ambient temps are present. The oxygen causes the exhaust products to reduce until the catalytic converter heats up and can operate.

'jsap' -- I am having trouble accessing the Mercedes site "epc.startekinfo.com". I can access "startekinfo.com" but like you say --why pay big bucks when I'm not planning on making a habit of repairing Benzes. When I try the "epc ---" I get a "server not found" message. Am I doing something wrong?

Last edited by stoic; 08-09-2010 at 01:03 AM.
stoic is offline  
Sponsored Links
Advertisement
 
post #12 of 26 (permalink) Old 08-09-2010, 02:43 AM
BenzWorld Member
 
jsap's Avatar
 
Date registered: Jun 2008
Vehicle: R129
Location: NorCal
Posts: 343
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by stoic View Post
'eric' and 'jsap' -- Thanks for the advise. It appears that the 'switchover' valve is a simple electrically operated vacuum switch. I can easily work on electrical and vacuum systems. I did some more research and now pretty much understand the system. It injects air into the exhaust for up to 90 seconds once the engine is started and certain ambient temps are present. The oxygen causes the exhaust products to reduce until the catalytic converter heats up and can operate.
That's right. It's just to get the cats heated up. On other makes, this is usually called the smog pump, and it does operate during other conditions. I just don't know if this thing operates on our cars after warm-up. The Germans do things sometimes differently. For instance, my engine (which is a model year '97) doesn't have an EGR valve (but I think yours does), nor a PCV valve. Weird, but true. Just for info, the EGR wasn't necessary on my engine, and the PCV operates on crankcase pressure alone that reverses the breather tube direction of flow into the intake manifold....

Btw, I don't know for your car for certain, but it *might* have both a switchover valve (an electric solenoid) that eric mentioned (which on my car is a rectangular metal box about 1" x 3/4" x 1.5" with little tubes going in and out of it, but I don't know about yours) and a check valve (which, on my car, looks like a round saucer about a 1.5" diameter). First thing should be to make sure the plastic tubes and rubber vacuum connectors are not deteriorated, and to clean any clogged passages. Then replace solenoids and valves before investing in the actual AIP pump.

Again, get on the W163 forum as soon as you can. I can't help you much more on your car....

Quote:
Originally Posted by stoic View Post
'jsap' -- I am having trouble accessing the Mercedes site "epc.startekinfo.com". I can access "startekinfo.com" but like you say --why pay big bucks when I'm not planning on making a habit of repairing Benzes. When I try the "epc ---" I get a "server not found" message. Am I doing something wrong?
Now, to help you get on epc....

Try this address:

"http://epc.startekinfo.com/epc/subscribe.jsp"

(or, you can go "http://epc.startekinfo.com/epc/" and click on the "subscribe" link)

Click on "I agree" at the bottom of the screen. Then, it'll ask you for the credit card info, but it'll tell you that the 1 year subscription is $0.00.

After this, depending on your Windows firewall situation, you might have an easy time or a difficult time getting the Java app to run correctly.

Once you've successfully subscribed, but if you can't get the Java program to run correctly, let me know again, and I'll help you diagnose your firewall settings.

In the mean time, see the picture below to get a sense of what you'll get with the free epc subscription. It's a great resource, and it's the dealer gets the same info. The image will show you highlighted both the check valve (mechanical) and the switch-over solenoid (electronic) for my SL500. When you enter your VIN number into yours, you'll be able to find yours by navigating to Engine/Intake/AirPump.... You'll figure it out. Just don't give up on the stupid computer obstacles....

Also, here's a picture of your A.I.R. pump.
Attached Thumbnails
Click image for larger version

Name:	epc.jpg
Views:	802
Size:	52.4 KB
ID:	324036  
Attached Images
 

Beware of stealers
(and shill posters who work for stealers)
jsap is offline  
post #13 of 26 (permalink) Old 08-09-2010, 01:03 PM
Outstanding Contributor
 
keyhole's Avatar
 
Date registered: Sep 2006
Vehicle: 2004 CLK 240 Coupe
Location: Norfolk. UK
Posts: 10,464
Mentioned: 10 Post(s)
Quoted: 356 Post(s)
You have engine 112. It seems that you are primarily interested in the locations/functions of the following.

K28 air injection relay
M33 air pump
N3/10 ME-SFI control module - (you referred to as ECU)
Y32 air pump switchover valve

These drawings from the WIS cover much of their activity.
Attached Files
File Type: pdf W163 air 1.pdf (624.2 KB, 73 views)
File Type: pdf W163 air 2.pdf (636.0 KB, 71 views)
keyhole is online now  
post #14 of 26 (permalink) Old 08-09-2010, 10:38 PM Thread Starter
BenzWorld Junior Member
 
Date registered: Aug 2010
Vehicle: 1999 ML320
Location: Saratoga, CA
Posts: 34
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
(Thread Starter)
'jsap' and 'keyhole' -- thanks to both of you for the info and help. I did some primary examination on the system today. It took me a while to figure out how to get the plastic top engine cover off. I didn't want to bust the darn thing. I kept looking for hidden bolts to remove. I finally got a little more forceful and the thing just pops off. I was then able to easily see the various components of the secondary air injection system. I attached a voltmeter positive lead to the large supply wire going to the 'air blower' and the negative lead attached to a good ground. I started the vehicle and no voltage was present. The ambient air temp was 22 degrees C. so the system should come on. I then went to the 40 amp fuse and checked it visually and with an ohmmeter. It was good. I then removed the k28 relay for the sec. air blower. The coil on the relay measured 78 ohms which seems about right for a 12 VDC relay coil. I didn't apply voltage to it because I'm not sure what the ECU sends to it although it is probably 12 VDC. I have some strips cut out of sheetmetal that are the same thickness and width as the blades on the fuse only they are a lot longer so a voltmeter can be connected to them. I stuck a strip into each of the two fuse holder slots. I then measured each strip and got no voltage. I then started the vehicle --and still got no voltage. It appears that the fuse holder is not connected to 12 VDC. I would think that the fuse should have one side connected to a buss bar strip on the under side of the fuse/relay board. I'll advise of my progress tomorrow.

"jsap"----I'm also on the ML benzworld part of this forum and I have received some good input and info.
stoic is offline  
post #15 of 26 (permalink) Old 08-09-2010, 11:13 PM
BenzWorld Member
 
jsap's Avatar
 
Date registered: Jun 2008
Vehicle: R129
Location: NorCal
Posts: 343
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
That's great. Do tell how you resolve the problem. I have a feeling I'm going to learn a few things....

Btw, I remember taking off the air filter box the first time. Looks daunting, but simple, isn't it. These cars are very easy to work on, so dig in!

Beware of stealers
(and shill posters who work for stealers)
jsap is offline  
post #16 of 26 (permalink) Old 08-09-2010, 11:26 PM
Outstanding Contributor
 
eric242340's Avatar
 
Date registered: May 2007
Vehicle: Zotye Auto 1.5T T600 2016
Location: The wild west of the Far East
Posts: 52,194
Mentioned: 3 Post(s)
Quoted: 291 Post(s)
Quote:
Originally Posted by jsap View Post
That's great. Do tell how you resolve the problem. I have a feeling I'm going to learn a few things....

Btw, I remember taking off the air filter box the first time. Looks daunting, but simple, isn't it. These cars are very easy to work on, so dig in!
I agree it is simple, but a word of caution. The front cover with the Benz badge has small clips and they snap off very easy and when this happens have some super glue ready

Also when refitting the air filter place a tiny amount of oil (I do mean tiny) on the rubber ring that meets the MAF sensor.

ERIC.

___________________________________________
"I am enclosing two tickets to the first night of my new play; bring a friend, if you have one."
- George Bernard Shaw to Winston Churchill.

"Cannot possibly attend first night, will attend second ... if there is one."
- Winston Churchill, in response.
eric242340 is online now  
post #17 of 26 (permalink) Old 08-10-2010, 11:01 PM Thread Starter
BenzWorld Junior Member
 
Date registered: Aug 2010
Vehicle: 1999 ML320
Location: Saratoga, CA
Posts: 34
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
(Thread Starter)
I resolved the problem with my 'sec. air inject.' system today. As I mentioned above --I was not getting 12 VDC at the 40 amp fuse holder on either side of it. I found out that the fuse is after the control relay. The contacts on the relay need to close before voltage passes thru and goes to the fuse and then on to the blower motor and switchover relay. I pulled out the relay and installed sheetmetal strips into the four slots where the blades from the relay normally go. These strips stick up a ways so I can attach a voltmeter to them. The relay has four blades on it. Two of the blades are large. These are obviously the contacts that switch up to 40 amps to the blower etc. On one of these large contacts I read 12VDC without the key turned on. This contact is probably connected to the battery at all times. I then placed a jumper from this contact to the other large contact and the blower actuated. I next examined the smaller two contacts that go to the relay coil. One of these two contacts gets positive 12 VDC supplied to it when the ignition key is turned on. The other contact gets a ground placed on it if the ECU (Electronic Control Unit) wants the 'sec. air inject.' system to function.

With a voltmeter connected to these two contacts I started the vehicle. I read 12 VDC. This meant that the relay coil should be operating. I next removed the relay and applied 12 VDC to it on the bench. I could hear it actuate. I connected an ohmmeter across the two large contacts and it read 'open' instead of 'closed' when the relay was actuated. I then removed the plastic case on the relay. I could then see that the two contacts appeared burnt. I removed the armature plate of the relay which held one of the contacts. I was then able to clean and deposit some molten metal onto the bottom contact. I cleaned and polished (using a Dremel) the top contact and then reassembled the relay. Manually closing the relay now showed continuity between the two contacts. I re-installed the relay in the vehicle and could now get power to the blower and switchover relay upon startup. I erased the trouble code and took the vehicle for a test drive. No more "check engine light".

Last edited by stoic; 08-10-2010 at 11:39 PM.
stoic is offline  
post #18 of 26 (permalink) Old 08-10-2010, 11:49 PM
BenzWorld Member
 
jsap's Avatar
 
Date registered: Jun 2008
Vehicle: R129
Location: NorCal
Posts: 343
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Wow, I didn't know you could speak Spock. Kidding. I love that you're technical. But, seriously, what the haden is "deposit some molten metal"? Is that the technical term for soldering?

So, something inside the relay was fried open, so you soldered them back together. I wonder what caused that over-voltage? I don't know your car so I don't know what components it has, but maybe your base module, or over-voltage protection, or voltage regulator is not kosher?

Anyway, as long as your smog pump turns on in the morning and shuts off after a minute or so, you're good!

Cheers!

Beware of stealers
(and shill posters who work for stealers)
jsap is offline  
post #19 of 26 (permalink) Old 08-11-2010, 12:49 AM Thread Starter
BenzWorld Junior Member
 
Date registered: Aug 2010
Vehicle: 1999 ML320
Location: Saratoga, CA
Posts: 34
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
(Thread Starter)
"jsap" --- You question what I meant when I said that I deposited molten metal onto a relay contact. The metal, that I deposited, was mainly tin and -yes-a soldering gun was used to melt the metal. I do not like to mention solder when it comes to rejuvenating switch and relay contacts. I have been doing this for 40 years. The average person thinks that solder will easily melt and is bad for this purpose. Little do they realize that almost all normal switches and relay contacts are tin. The two surfaces on the relay in question were badly burned and pitted. When they were pressed together --they did not make an electrical connection. After making a smooth and shiny surface on both of the contacts --they now make a good electrical connection.

I am old and have been working on electricity and mechanical problems for around fifty years now. Electrical contacts, when switching an inductive load such as the blower motor and relay in the switchover relay, receive a very high back EMF when they open. This causes very high heat and arcing of the contacts. There is a diode mounted inside the relay which moderates this. My relay simply had contacts which had started making bad connections and as time went along --this only got worse. Eventually the contacts were destroyed. I cleaned, installed a new coating and filed and polished them. I'm semi-retired and what better way to waste my time?

I realize that this repair would probably be better if I simply installed a new relay.

Last edited by stoic; 08-11-2010 at 01:09 AM.
stoic is offline  
post #20 of 26 (permalink) Old 08-11-2010, 01:01 AM
BenzWorld Member
 
jsap's Avatar
 
Date registered: Jun 2008
Vehicle: R129
Location: NorCal
Posts: 343
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
No, I like your repair better! You're my new hero!

Btw, what causes the relay to blow like that? Was this due to a slow corrosive process, or was it an electric surge?

Beware of stealers
(and shill posters who work for stealers)
jsap is offline  
Sponsored Links
Advertisement
 
Reply

  Mercedes-Benz Forum > General Mercedes-Benz Forums > General Mercedes-Benz

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Mercedes-Benz Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











  • Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
     
    Thread Tools
    Show Printable Version Show Printable Version
    Email this Page Email this Page
    Display Modes
    Linear Mode Linear Mode



    Similar Threads
    Topic Author Forum Replies Last Post
    air pump malfunction Old Techie R/C107 SL/SLC Class 7 06-09-2010 07:29 PM
    Air conditioning malfunction PensBenzFan W251 R-Class 2 08-06-2009 03:04 PM
    Po410 secondary air injection malfunction Solidjake W163 M-Class 4 09-14-2008 04:47 PM
    P0410: Secondary Air Injection Malfunction Cklasse303 R170 SLK-Class 5 05-04-2005 02:08 PM
    Air Mass Meter Malfunction brownshoe W210 E-Class 4 03-20-2005 01:04 AM

    Posting Rules  
    You may post new threads
    You may post replies
    You may not post attachments
    You may not edit your posts

    BB code is On
    Smilies are On
    [IMG] code is On
    HTML code is Off
    Trackbacks are On
    Pingbacks are On
    Refbacks are On

     

    Title goes here

    close
    video goes here
    description goes here. Read Full Story
    For the best viewing experience please update your browser to Google Chrome