By the way this is on my 2000 S500.

 

INFORMATION ON SPECIFIC SAM FUNCTIONS

A SAM (Signal Acquisition Module) functions much as a network router does on a computer or communications network. It monitors input from various switches, controls, monitoring devices, and warning systems. When you push a button on, for example, your dashboard, the signal goes through a SAM before the device you are controlling responds. If there is something wrong with the device you are trying to operate, you will likely then get a warning, delivered through the SAM to the CAN (Controller Area Network) bus. The CAN bus will send the error message to the "error screen" you mentioned (the Multifunction Display, beneath your speedometer), or elsewhere in the instrument cluster. You may also get messages indicating normal operation, such as "car rising" when you raise it by the Airmatic system.

There are SAM units at each large fuse panel (the fuse panels are mounted on them and connect to them): The two under the hood and the one under the right side of the rear seat. In addition, the "electronic fuses" identified in the fuse diagrams are located within the SAMs. See posts 6 and 12 at http://www.benzworld.org/forums/w220-s-class/1310396-electronic-fuse-location-2.html for more on electronic fuses.

Thanks to member BulletheadD, we have the following information on specific SAM functions. This is for a W220 with CODE (614) Bi-xenon headlamp unit control unit N10/7; other models may models may have slight differences, but the following should illustrate the point.

In the descriptions below, "Right" and "Left" are from the driver's seat, facing forward, per the Owner's Manual, and as shown on the fuse diagrams.

The left SAM in the engine compartment deals with all left front lights and the side light - except low beam (which comes from the right SAM), further rear air outlet illumination and glove compartment lock illumination. It also interacts directly with rotary light switch, the HCS switch, the steering column adjustment motor group (the motors via left front fuse and relay module), ESP, SPS and BAS control, with AIRMATIC with ADS control unit or ABC control unit and via right front fuse and relay box with refrigerant compressor.

The left SAM gets signal input from the left front brake pad contact sensor, refrigerant pressure sensor, refrigerant temperature sensor, outside temperature display temperature sensor, brake fluid indicator switch and parking brake indicator switch.

The right SAM in the engine compartment deals with all right front lights and the side light - except low beam (which comes from the left SAM), and also the lights in glove box, center console storage and eyeglass compartment, ashtray and footwell. It also handles heating and pumping for the windshield washer nozzle and washer nozzle hose and pumping water for the Headlamp Cleaning System; and the additional fan (radiator fan) for coolant, the fan for transmission oil cooler, and the circulation pump for the heating system delivery unit.

The right SAM gets signal input from the right front brake pad contact sensor, coolant level indicator with windshield washer fluid level indicator (both are in series!) and Anti-Theft Alarm [EDW] hood switch. Incoming and outgoing signals for the switches and controls for lights, pumps, heaters and so on in most cases are delivered via CAN from and to other controllers.

The rear SAM below the right rear seat cushion interacts directly with the trailer recognition control unit and with the ESP, SPS, BAS-controller. It communicates e.g. with the overhead control panel control unit via CAN. It also deals with all rear lights, closing the trunk and fasten seat belts indications; additionally it reads the tank level sensor, a tilt sensor (Anti-Theft Alarm inclination sensor), all 4 door contacts and the rear brakes sensors.

The relay for the fuel pump is placed near the rear SAM but normally it will get its signal from the ME. Only AMG versions have an extra controller for the fuel pump.

In addition to the fuses and relays, as mentioned, the SAMs have connections to the CAN busses. Some of these connections are located under the front seats of the car. Getting those connections wet due to water intrusion can also cause problems in equipment routed through the SAMs. And, the SAM under the back seat seems particularly affected when significant amounts of water intrude into the car.

Your car has three CAN busses. CAN B is the interior (or body) data bus; CAN C is the engine/chassis data bus; and CAN D is the diagnostics data bus. One can read possibly more that you wanted to know about CAN at http://www.mercedestechstore.com/pdfs/507 Systems I/507 HO CAN B (ICC) 10-28-02.pdf

One can see that a problem may occur at the operating control; at the component being operated; somewhere in the CAN bus; or in the SAM itself (including fuses and relays). The first thing to check are fuses and relays; then, the component; then the operating control - and if the problem affects many components or switches, suspect the SAM. You can get a good idea if you have a SAM problem if you see malfunctions in multiple systems all operated via the same SAM. However, be sure to note Eric's cautionary note in post #13 below. SAMs don't fail often, and when they do it is frequently because they have been soaked in water.

One other thing that can cause random, repetitive error messages and malfunctions is a failing battery.

As far as replacing it, see http://www.benzworld.org/forums/w220-s-class/1642835-s430-low-beam-right-replaced-bulb.html - and note that they are expensive. I would suggest having a proper diagnosis done with STAR to confirm that replacement is needed.

 

A SAM (Signal Acquisition Module) functions much as a network router does on a computer or communications network. It monitors input from various switches, controls, monitoring devices, and warning systems. When you push a button on, for example, your dashboard, the signal goes through a SAM before the device you are controlling responds. If there is something wrong with the device you are trying to operate, you will likely then get a warning, delivered through the SAM to the CAN (Controller Area Network) bus. The CAN bus will send the error message to the "error screen" you mentioned (the Multifunction Display, beneath your speedometer), or elsewhere in the instrument cluster. You may also get messages indicating normal operation, such as "car rising" when you raise it by the Airmatic system.

There are SAM units at each large fuse panel: The two under the hood and the one under the right side of the rear seat. Fuses and relays connect to them. In addition, the devices called "electronic fuses" are located in them. See posts 6 and 12 at http://www.benzworld.org/forums/w220-s-class/1310396-electronic-fuse-location-2.html for more on electronic fuses.

In addition to the fuses and relays, as mentioned, the SAMs have connections to the CAN busses. Some of these connections are located under the front seats of the car. Getting those connections wet due to water intrusion can also cause problems in equipment routed through the SAMs. And, the SAM under the back seat seems particularly affected when significant amounts of water intrudes into the car.

Your car has three CAN busses. CAN B is the interior (or body) data bus; CAN C is the engine/chassis data bus; and CAN D is the diagnostics data bus.

One can see that a problem may occur at the :surrender::bowdown: control; at the component being operated; somewhere in the CAN bus; or in the SAM itself (including fuses and relays). The first thing to check are fuses and relays; then, the component; then the operating control - and if the problem affects many components or switches, suspect the SAM.

One other thing that can cause random, repetitive error messages and malfunctions is a failing battery.

As far as replacing it, see http://www.benzworld.org/forums/w220-s-class/1642835-s430-low-beam-right-replaced-bulb.html - and note that they are expensive. I would suggest having a proper diagnosis done with STAR to confirm that replacement is needed.

hi skylaw I also just a got thru a nightmare scenerio with my dealership. Anyhow I have a list of what's wrong with my battery drain.
1= Left Sam recommend replacement.
2= Coolent leakage from water pump.

Out of curiosity am i able to purchase a new or used Sam and replace it and would it fit and work or not.

How easy is it for a water pump replacement and a ball park in terms of price.

As always thank you.

 

The last link embedded in post #3 indicates you can replace a SAM yourself. I suggest you be very certain that you get one made for your model and year of car. I do not have that part number, except to say it is very likely on the SAM you are going to replace. Also, while there are a number of SAMs available on ebay, if it doesn't work you may not be able to return it. Personally, I would buy that part new.

A number of replacement water pumps are available, from a number of sources. They run from approximately $85 to under $145 for the part at Mercedes S430 Water Pump - Free Shipping - Replacement, GMB, A1 Cardone, but be sure to shop around.

Again, I understand why you may not wish to purchase one from your particular dealership.

I don't know the time required to replace the pump and "burp" the system to eliminate air bubbles, so I can't help with cost for labor.

 

Skylaw your a breath of fresh air on here. I love you. Hahah. After installing the new Sam do I need to take it to MB for resetting the codes or anything or just replace and enjoy.

Regards.

Karam.

 

Judging by what I have seen in other posts, I believe it is only a matter of remove and replace - if I'm wrong, please jump in here before I steer Karam wrong.

 

Great glad to hear. A lot of guys selling them on eBay but I'll pick up a brand new one just to be safe. And I'll let you know what happens. By the way thanks for the link on the water pump as well.

 

slow battery drain.

Just wondering but I believe my SAM module is defective from reading other posts. My car gives random side light error message and on occassion windshield wiper low error and coolant error. There is nothing wrong with any of these things. Once an error shows I can't scroll out of it either. Im stuck at the error screen. Any ideas?

after a year of dealing with slow battery drain, and trying to fix it my self with a local mechnic, i broke down and went to the dealer, it was rear sam, replace it for 850 bucks. folks spend the money it was worth it, i've research on this site. but i think its alwasy the sams!

 

slow battery drain.

after a year of dealing with slow battery drain, and trying to fix it my self with a local mechnic, i broke down and went to the dealer, it was rear sam, replace it for 850 bucks. folks spend the money it was worth it, i've research on this site. but i think its alwasy the sams!

i had the rear sam replaced, then came the front, total $1500, now the dealer says its still drawering down, and i have to replace head unit, taking out nav disk isnt enough, 3k at dealer they were kind enough to tell me to go on ebay or new afeter market.

 

Just wondering but I believe my SAM module is defective from reading other posts. My car gives random side light error message and on occassion windshield wiper low error and coolant error. There is nothing wrong with any of these things. Once an error shows I can't scroll out of it either. Im stuck at the error screen. Any ideas?

Without diagnostics it is foolish to blame an expensive SAM unit. You should look at each of these error messages and check each system fully. To get out of the message on the IC simply press the R button on the screen.

 

I agree with Eric. The discussion of what a SAM is at post 3 recommends diagnosis before replacement, and Karam had had his problem diagnosed before deciding to replace. While a SAM coordinates many types of input, the problem may still lie with the component one is trying to control, or that is giving a trouble indication. Further, some MB warning systems have multiple items on them, and a failure indication could be given by a malfunction on any of those items.

 

The SAM is a mere medium and takes in signals and then relays them to the correct control unit far too many DIY chaps and Benz techs alike blame the SAM, when the SAM is a messenger and rarely a cause.

First look at each message and test each system and only if you find each system OK, then check the SAM. It is rare to change a SAM unit but some were defective on certain years and models.

 

Info on specific SAM functions - Updated

Post 3 has had specific information on the operation of and systems controlled via the SAMS added - Thanks, BulletheadD!

 

ML320CDI 2006

My ML320CDI 2006 model has had the leaky tail lights issue causing the SAM to get wet (I have confirmed this by taking it out)(SAM located in boot in right rear panel under fuse box)

Now the faulty systems/issues all faulty at the same time Im seeing is
1) Power tailgate not working (doors central locking working ok)
2) left and right indicators not working (although hazards do work and also when locking car the indicators do light up)
3) Back lights not working when lights on
4) Fuel Gauge reading full all the time.

from research it seams that the SAM getting wet is the issue and needs to be replaced?
Anyone care to confirm if from the symptoms this makes sense?

 

You may get a better response in the W164 forum, which is for your model ML.

If it will be of any help, the W220 S-Class Encyclopedia has a link in the section discussing SAMs that shows what each one operates but the info is for the S-Class, not the ML. However, if the ML wiring is similar, it does sound like a rear SAM problem - by all means check http://www.benzworld.org/forums/w220-s-class/1644809-what-sam-module-how-do-you.html

If components in the SAM have not been blown from being operated when wet it may be possible to save it by removing it and dry it carefully with a hair dryer. There is some info on this in the imbedded links in the thread at http://www.mbca.org/forum/settlement-class-action-suit-interior-flooding

 

You can repair the SAM yourself

Don't go out and replace your SAM modules without first trying to fix them yourself. It's pretty easy but time consuming, it took me about five hours to properly clean the rear sam in my 2001 Mercedes Benz S500. These SAMs are known to corrode and get that green stuff on them in the inside since their made out of copper in the inside and gold plating on the outside.

Step 1 - Disconnect the negative terminal on the battery.

Step 2 - Remove the bottom rear seat by pressing two buttons, one on the right and one on the left underneath the seat. Once the seat is removed lift up the plastic covered insulation and mat covering the SAM module.

Step 3 - Remove the metal cover on top of the SAM module and place it to the side.

Step 4 - Take pictures of all the cables and where the fuses go.

Step 5 - Disconnect the fuses and cables.

Step 6 - Disconnect the little computer underneath the SAM

Step 7 - Where the fuses were connected you'll notice clips and once opened will allow you to separate it and inside that is what needs to be disassembled each metal piece inside will need to be cleaned and sanded to remove the erosion. Make sure to clean everything and make sure you take pictures of where each little metal piece goes otherwise you'll never put it together again. The inside of the SAM is in three sections separated by pieces of plastic where the metal clips go into. Do a section at a time, start with the section that would be towards the back and work your way forward to where the fuses and relays would plug into.

I'm no mechanic but I was able to do it, it just takes time and patience and you must also be meticulous about it.

The reason I did this is because I knew it was the corrosion messing it up causing the voltages drop causing the rear lights to fail and the fuel gauge as well.

I hope this helps and don't be afraid to do it, it's already messed up...

 

I just replaced my rear SAM on my 2000 S500. It had the corrosion on it which is from water intrusion through the AC/heat vent in the firewall. If you don't remove all of the moisture under the carpet, there is a good chance the problem will re-occur. The carpet has a backing that is some sort of moisture barrier, so the water will not just dry out. Additionally, the massive amount of foam on the back of the carpet allows large amounts of water to remain under this moisture barrier (when I removed my carpet, it weighed 30 pounds). The barrier keeps your carpet from molding, but you keep the water a long time, potentially ruining a new replacement SAM (and wasting 400 bucks). Also, the plastic electrical conduit needs to be opened and dried. Further, the insulation padding behind the steel foot plate in the front passenger footwell holds a fair amount of moisture as well. To be ABSOLUTELY CERTAIN that you have removed all the water, you must remove and dry ALL the carpet, which necessitates removal of both front seats and the console. Only then would I install a replacement SAM.

Incidentally, I used a SAM from a wrecked S430 of the same year. It had the same part number that was designated for an S500 on Pelican Parts. No coding of any kind was necessary. It's plug and play. By the way, if you unplug only one connector at a time from the defective SAM and replace it in the correct receptacle on the new one, there is little chance of mistaken wiring.

As an aside, I took apart my defective SAM. As El Papi Chulo 77 said, it comes apart quite easily. Inside you will see a circuit board. If an onboard component was shorted by moisture, Papi's solution may not work, as effective diagnosing of which component is defective is not possible without some sort of schematic. However, if the connections are simply corroded, cleaning may get you back on the road cheaply. Even so, if you don't dry out the carpet and solve the underhood water problem, you may be seeing that SAM again in the near future.

 

El Papi Chulo 77 and haroldwca - thanks for your comments. Very helpful. :thumbsup:

 

Last night I also changed my rear Sam because the previous owner had spilled soda on the rear seat which went into the rear sam. Which also caused problems like rear tail lights staying on, and showing one of the doors was open all the time. First I had a replacement rear Sam for the car but the part number did not match mine. When replaced everything worked like it should no problem but my gas gauge was showing 0. Then i replaced the rear sam with the appropriate part number matching my original one and everything works like it should. Was just plug and play. BUT BE SURE IF YOU ARE REPLACING YOUR REAR SAM UNIT, THE PART NUMBER MUST MATCH. I got the part where my s/w version and h/w version even matched.


Sent from AutoGuide.com Free App

 

Help, none of my center console buttons work on my 02 cl500.

 

Eddie Cee, there isn't really much to add to the discussion that would help you. Your W215 and the W220 of the same model year will have very similar systems, and I suspect that most of what s already here would carry over to your car.

However, SAMs are expensive; before throwing money at parts, you would be wise to have diagnostics performed at a dealership or a good independent, and handle the problem from there.

 

Absolutely, but before he runs off to find a diagnostic workshop, he should open the drivers door and on the side of the dashboard is a plastic panel, pull this off and inside is a fusebox, check all the fuses in there.

 

The question that still remains after reading this post is "How do you replace the SAM module"?
I've unplugged the wires on top from the connectors near the fuses. Pulled the latches on either side, but when I pull up, there is resistance and when I look over at the side, there are wires coming from below that are connected to the underside of each fuse. This seems to stop the entire assembly from pulling up.

Question: Do I pull harder and is there enough length to the wires underneath that the whole unit is supposed to pull out as shown in this photo?

 

You have a couple options here.

MUST:
remove the four plugs towards the bumper on top. 3 of them are visible in your pic and there should be a 4th in that cluster with a pink wire going to it. May be diff on your year model. Once those are removed you have your pick of options,

The easiest: take a flathead screw driver and put it in between the metal and the plastic. there are two slots, insert and twist, you can do one at a time and the SAM will pop off the fuse box.

Slide it down and off of the track. There are 2 on either side this is also how to align in it on re-installation.
Once its completely separated you can pull the fuse box out of the way and pull up on the SAM itself. Go slow, you don't want to clip/pull/break any wires. You should be able to lay the same on its side on top of the airmatic computer and pull off the first two plugs by pressing down on the release tab while pulling the grey release "lever" down.(or better put, forward, toward the release tab) you'll see it works kind of like a gear when it starts moving.

The teal/green plug you will notice has a small tab, you can use either a pick or the corner of your flathead to push it it and then down/out in order to disco with your fingers. I believe those are the CAN lines so be extra gentle with them. Then you will have full access to easily remove the final black connector with thumb and forefinger. SUCCESS

Option 2,
disco pos terminal @battery, pull up on the positive wire lock release to rear of fuse box, then begin taking off each fuse harness using flathead electronics or glass screw driver to release the tabs. I recommend taking pictures and going in order. the fuse harness not only plug into the box but each other on a lateral plane. once they are removed you can pull the whole assembly out and remove the harness going to the SAM per instructions above

 

Thanks! I ended up with Option 1. The SAM was slid down from the fuse assembly. Took it apart after that but everything was just circuitry and nothing was out of the ordinary. Now if I could just get the AC to work...

 

I mightve missed you previously in the thread.

What is it you're trying to do? Just replace the SAM or something else?

 

Although I will take the Beast to local indy shop, any suggestions would be helpful. Here's my situation:

After engine heats up and then car is turned off (doesn't matter if key is removed from ignition or not), I get EPS, ABC, BAC, ABS error codes. All show up EVERY time this happens. Rear brake lights then are on for the duration until the quick fix is implemented. Soft close driver's door also fails at this time. Car will still start and run, but with pre-safe inactive. If one then turns off the ignition, the car will no longer turn over.

Almost always, removing the negative terminal on the battery for a few seconds clears all error codes, car starts and runs like a champ.

From previous posts, sounds like front left SAM, but could also be rear one with the brake lights integrated into the failure cascade.

2003 S600. ~220k miles. Designo mocha.

Thoughts?

 

What are the fault codes?

 

FRA A 1426, FRA V 1426. That's all I got out of the A/C unit when searching for error codes. Got it to malfunction today after 10 minutes of driving and temp just at 80C. Any help would be greatly appreciated. Don't have a STAR and want to be armed before going back to Indy. Recently replaced key fob, as both Indys I use from time to time said that was likely the culprit.

 

Sorry but those codes are not fault codes, impossible to even start diagnostics without codes, especially on a complex problem such as this one.

 

This is a very old post.. hopefully someone sees this... the control unit went on me about 6 months ago... now we have constant battery drain.. would anyone know what which sam would be responsible for this to occur....TIA!