I have a w164 ml350 and for some reason, my key fob range is very poor. Car works perfect otherwise. I tried changing batteries and used another fob so I think its something with the antenna... Anyone have this issue and know how to fix it?

 

Any common areas that might have a disconnect or easily accessible areas?

 

Hey, attempting to revive this thread. I am experiencing a similar problem with both of my key fobs. Remote unlocking via RF just stopped working yesterday but the IR unlock is still functioning perfectly. I have had the rear SAM replaced just over a year ago due to water damage and replaced the rear tail light seals while I was at it (thicker seals adhered to the body not light assembly). Any ideas of what the problem could be? Any and all help would be greatly appreciated!

 

Joe, you must scan the entire car for codes.

 

Make sure the batteries you changed them with are good! New doesn't always mean good.

 

Any suggestions for a good full vehicle system scanner? Right now I just have a cheap bluetooth version for live streaming data. And yes, I did check the new batteries and they were right at ~3.3V.

 

This one will read all modules.

 

Thanks Major! I have since purchased the scanner and scanned all modules. The rear SAM had the following codes stored:
90C4 - Interference suppression filter short circuit
9095 - Component F4kR has short circuit
9102 and 9103 - Left brake line short circuit
9136 and 9137 - Right tail lamp short circuit
913E and 913F - Right backup lamp short circuit
9127 - Left tail lamp short circuit
9106 and 9107 - Right stop lamp short circuit
912F - Right rear fog lamp short circuit
912B - Left backup lamp short circuit

After seeing this, I pulled out the rear SAM and sure enough there was water inside of the case, but no water in the body panel underneath. Prior to this finding I had already pulled out the spare tire + all tools and removed all carpet from the cargo area and the sheet metal underneath was completely dry and didn't appear to have any signs of water intrusion. I had replaced the tail light seals with the thicker seals and adhered them to the body of the vehicle (not the plastic lip on the tail light assembly) about a year ago when my last SAM got fried, so I'm wondering if there is another source for water intrusion on these vehicles? Either way, I am in the process of cleaning the corrosion off of this board. The corrosion on this board is much much less than my last SAM so I am hopeful that I can salvage it.

 

Hopefully you own your own home and being that the rear SAM is removed, spray water all around the right tail lamp for a minute or so. The spray must be forceful.

 

I'm having similar issues. If you scroll down the main page of the 164 thread's you'll see I posted about this fairly recently. I too replaced with the new seal (to the body) and am still getting water in. I ordered a gasket making material and am going to try to just seal the entire light fixture. I also ordered desiccant packets that I'm leaving in the SAM area but after receiving them it says they only work in an air tight seal. I left them in figuring something is better than nothing. If you find another location of water entering please report where. I'll come back to this thread after I make my new gasket (in addition to the MB one on the inside of the light fixture attached to the body) after spraying it with water and let you know if that solved for me. Super upsetting that something this simple can't be rectified by MB and if I can't locate my water source...I'm thinking of just selling this vehicle because it is frustrating me so much and I don't want to have to keep dealing with cleaning or even worse replacing the rear SAM. Best of luck!

 

If you lift the tailgate and look at the plastic surround, that seals around the body. Is it cracking just above the rear lights?

 

No, not on mine. Everything looks as it should. No cracks anywhere all around with the lift gate up. Just incredibly frustrating, everything appears as it should yet water comes in still. I only noticed because I randomly checked after washing my car. I'm even afraid to type this - but luckily not because I was having issues leading me to believe the rear SAM might have been exposed to water.

 

The other really mental thing I found with my car is. On the very top of the LHS rear wheel arch. You have to remove the whole of the storage bin to access it. There was a circular hole punched through the wheel arch! This had the displaced flap of steel just pointing up vertically, still attached to hole. I wish I'd taken photos as I don't know how this description works! Anyway, this flap and the edge of the hole were all rusty, so water has clearly been getting in there for years.

I treated the rust and hammered the flap back down, sealing the edges with some wax spray. Why on earth would they do this? What possible function could it serve? You can change lamp seals all you like but if high pressure water is jetting in from the wheel arches then you're flogging a dead horse.

I'll check the RHS one day, I just didn't fancy removing the wiring and sam stuff.

 

Maverik, I would definitely remove your SAM and check it for signs of corrosion since you know you have water intrusion. If you catch it before the corrosion shorts anything out on the board you can easily clean it before it gets damaged and begins to show symptoms.

 

Joe - Absolutely. I plan on cleaning it again but I'm trying to figure out where the water is coming from first. I don't feel like there is a reason to do that just to have it get wet again next week. I also don't have garage space for this vehicle to pull it in take out the SAM and try to remedy it before reinstalling. I can't leave it blocking my driveway either. So I'm trying to do my best to figure out where the water is entering, seal it up, clean the SAM and return it to service. Until I can do this, I have it under an outdoor car cover so I know it's not getting more water in just driving me crazy. I wish I had the space to remove the SAM and spray it with water until I could rectify it but my home layout doesn't allow that right now.

 

I'm not one hundred percent sure this is what your talking about but...I've read on the forums for the rear SAM issues that MB put vents back there. The purpose of these vents was to allow air to escape when people closed the doors. I have no idea. I remember the last time I had my SAM out I saw some sort of vent and thought about sealing it off and don't think I did. It's been a while now so I'll really need to look once I get it out again to re-clean it. No idea why they would put that vent in such a critical spot either. I'm not an engineer though so it's very likely I just don't know/understand enough about it. It's been over a year since I removed and cleaned my SAM and my memory just isn't that great for that. I was too excited to try and rectify my issue and truly believed MB had figured it out with the new lamp seals.

 

I'm needing to order more cleaner and wondering what you guys have used and think is best for cleaning the SAM. I was browsing amazon and found this cleaner/protector do you think it's the best option or is there another product that I should try? Last time I did this I was at my buddies house and just used the aerosol electronics cleaner he had, but I don't remember the brand.

 

Here it is.

 

Thanks Major. That's what I'll get. I had my friend check his garage and last time we just used Napa brand cleaner. In no way am I challenging your recommendation and I see how helpful you are on the forum, but can you tell me why that cleaner vs the cleaner and protector? Appreciate any insight just for my curiosity.

 

Any electronic cleaner will do but I have no knowledge of cleaner protective.

 

I agree with Major, I have used the CRC electronics cleaner on multiple occasions with great success.

Since cleaning and re-fitting my SAM I am left with only 1 existing error code and that is:

90C4: The cable to component interference suppression element has short circuit or no connection.

This leaves me with full functionality of brake lights/wipers/etc. but no remote unlock. Major, do you know what plug on the SAM and pins are related to this element? I want to check the wire harness for signs of damage (or any corrosion on the board that I may have missed) and would like to know where to start.

Thanks!

 

Gotcha. I was just curious because the link I posted is from CRC just a different spray.

 

When you cleaned the rear SAM, did you remove the plastic covers and the pin connector towers?

I have no idea what the Interference Suppression is. Give me some time to find it.

 

The interference suppression element is for the rear audio. Are you having any problems with that?

 

No, all audio is working properly (speakers work and radio stations come in just fine). When I go to view live data and look at "radio reception of central locking system" and try to unlock/lock the vehicle I do not register any signals. Oddly enough the lock/unlock worked out of the blue for about 5 actuation cycles and then stopped working again (scanner was not plugged in when this happened). This leads me to believe I have a faulty contact/intermittent contact on that circuit? Best, Joe.