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Remote Key Sync..Works..but doesn't work??

51K views 74 replies 32 participants last post by  43sqd 
#1 ·
Hey, it's been awhile since I've posted on the forum. A couple of month's ago my remote stopped working completely. So I was like ok, it needs new batteries so I bought new batteries for it. After replacing the batteries, I got on the forum and did my research on how to sync the remote, I tried to resync the remote many times according to the procedure. I did the procedure,...turn key to on position, then turn the key to off
press and hold lock while pressing unlock 5 times repeatedly...then press any button... ok so After a press any button, lets say I press the lock button...the doors will lock, my turn signals blink 3 times and the alarm is set....after it is set...I want to unlock my car so I press the unlock button..and nothing happens...I'm locked in my car! So I have to redo the procedure in order to unlock my car...So the sync procedure goes through but my remote doesn't work...has anyone experienced this?? Any suggestions or help would be appreciated! Thanks!
 
#4 ·
LtnML -- did you ever find out what the problem and/or solution was for this?

I have the same problem. I bought a new second key from the dealer and they synced it, worked for 6 months then stopped working--exactly as you described it. Replacing batteries did not solve it, and re-sync as described in the manual and on threads in this forum works only once (lock or unlock) after the procedure. Dealer said the car recognizes the key (proof is how it works once after re-sync), but they don't know why is does not work after that--so they suggested replacing the AAM for $500. I passed, and now 4 months later my original key has stopped working with the exact same symptoms.

I would like to avoid the expense of replacing the AAM if at all possible, especially since the dealer can't say for certain if that is the problem or if it will resolve it. So any advice from anyone familiar with this situation would be helpful.

Thanks!
 
#11 · (Edited)
Hello to everybody out there!

I am having the same situation. My 3 keys wont lock/unlock the doors with the remote. Replaced batteries on all 3 remotes.

I can start and run the truck but locking and unlocking the doors manually.

Also the auto locking of the doors at 9mph is not working. I tried re syncing the 3 remotes and activating the auto locking feature like the users manual describe but nothing happened.

Took the truck to my MB dealer they tell me the EAM and ECU needs to be replaced at $3866. Form other post I have read that problems with the remotes are related to an AAM malfunctioning.

Can anyone shed some light on my problem or if anyone have solve the problem without replacing the EAM , ECM or AAM, please let me know.
 
#5 ·
Can I just throw a random theory out here? What if the battery (not key battery) is weak and not holding a charge. Could there somehow be loss of memory in the keys that would subsequently require key resyncing?

It's an unfounded and rather random theory, any thoughts?
 
#6 ·
Thats what happened to my mum when she tried to get into my 320 unfortunately the main battery had discharged. Re charged the battery and she was able to unlock/lock my ride without the need to resynch the key. In any event i have ordered a spare key from MBUSA via OEMPARTS DIRECT. Do i still need to resynch the key and get it programmed to the AAM or has it been done already?
 
#9 ·
I had a similar problem with my wifes ML .
Bought a new key from MB dealer. After approx 8 mnt, and after a 2 mnt holiday, tried to start the car. Flat battery, (barely turned over). Jumped started the car. It would turn over, but as soon as it fired up, it would turn off. (Spare key would work OK).

Took the car/key back to the dealer. It could not be re-programmed, and new key was ordered free of charge.

They also said that there was a lot of problems with the keys for the ML only.
 
#13 · (Edited)
I have own the truck for two years and it came with 2 remotes, I ordered another one from my MB dealer (though I had lost one) and all 3 worked fine until a week ago.

Who is responsible for receiving the RF of the remotes, AAM or EAM?

Like you said I would like to have the remote feature but not for $3866, since I can still run the truck I think I can live without it.

I just checked the #42fuse and looks fine. Do not know how to tell if the all doors relay is ok, any help?
 
#19 ·
Hi there!

Just to summarize the issue, my power locks function with the console button and with the driver and passenger door using manually the key. Also I can start and run the truck normally so the DAS is recognizing all my 3 keys and authorizing the starting and running of the engine.

The only thing not functioning are the remote feature of the keys and the auto locking at 9mph feature.

Thanks to everyone helping.
 
#20 ·
I found this two documents which are very informative about the electronics of the ML.

Still I do not know how I can find out if the 2001 recall issued for the AAMII of the 2001 ML was performed on my truck?

On 2003 another recall was issued for a power steering hose clamp, same thing how I can find out if mine is fix or not?
 

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#22 ·
A few sites I found with the recall information.

2001 Mercedes-Benz M-Class ELECTRICAL SYSTEM:WIRING Recall at Automotive.com

2001 Mercedes-Benz M-Class ML320 Sport Utility Recalls, Defects, Recall Reports & Problems at InternetAutoGuide.com


2001 Mercedes-Benz M-Class Recalls & Problems at Motor Trend Buyer’s Guide

NHTSA Campaign ID Number: 03V121000

2001 MERCEDES BENZ M CLASS STEERING:HYDRAULIC POWER ASSIST:HOSE, PIPING, AND CONNECTIONS
Recall Date: 03/27/2003

Summary:
ON CERTAIN PASSENGER VEHICLES, THE HOSE CLAMP USED TO SECURE THE POWER STEERING FLUID COOLING HOSE TO THE POWER STEERING FLUID COOLER MAY NOT PROVIDE SUFFICIENT CLAMPING FORCE FOR THIS CONNECTION.

Consequence:
THE LOSS OF POWER STEERING FLUID MAY RESULT IN DIMINISHED POWER STEERING OVER TIME AND ULTIMATELY CAN DAMAGE THE POWER STEERING PUMP.

Remedy:
DEALERS WILL INSTALL A NEW HOSE CLAMP ON THE POWER STEERING HOSE TO THE POWER STEERING COOLER. DURING CLAMP REPLACEMENT, THE POWER STEERING COOLING HOSE WILL BE INSPECTED AND REPLACED AS NECESSARY. OWNER NOTIFICATION BEGAN JUNE 16, 2003. OWNERS WHO TAKE THEIR VEHICLES TO AN AUTHORIZED DEALER ON AN AGREED UPON SERVICE DATE AND DO NOT RECEIVE THE FREE REMEDY WITHIN A REASONABLE TIME SHOULD CONTACT MERCEDES-BENZ AT 1-800-367-6372.

Potential Units Affected: 211000

Notes: MERCEDES BENZ M CLASS 2003-040005

NHTSA Campaign ID Number: 01V061000


2001 MERCEDES BENZ M CLASS ELECTRICAL SYSTEM:WIRING
Recall Date: 02/27/2001

Summary:
VEHICLE DESCRIPTION: PASSENGER VEHICLES. CERTAIN ALL ACTIVITY MODULE II (AAM II) COULD HAVE A SUB-COMPONENT THAT COULD CAUSE THE MODULE TO INTERMITTENTLY NOT FUNCTION PROPERLY. THE AAM II CONTROLS A NUMBER OF SYSTEMS INCLUDING THE HIGH BEAM LIGHTS, INSTRUMENT CLUSTER, DOOR LOCKS, AND WIPER SYSTEMS.

Consequence:
THIS CONDITION COULD CAUSE AN INTERMITTENT NON-FUNCTIONING OF THESE SYSTEMS.

Remedy:
DEALERS WILL REPLACE THE AAM II. OWNER NOTIFICATION BEGAN FEBRUARY 16, 2001. OWNERS WHO TAKE THEIR VEHICLES TO AN AUTHORIZED DEALER ON AN AGREED UPON SERVICE DATE AND DO NOT RECEIVE THE FREE REMEDY WITHIN A REASONABLE TIME SHOULD CONTACT MERCEDES-BENZ AT 1-800-367-6372.

Potential Units Affected: 377

Notes: MERCEDES BENZ M CLASS
 
#24 ·
I found the following document. It is bad news for me because it states that the vehicles affected were made between January 18 and February 1 of 2001. Mine was born on may of 2001.

I guess I will have to pay for the AAMII replacement. Unless somebody knows another way of fixing the remotes problem...I hope it can help somebody.:cool:

I found it here: Office of Defects Investigation (ODI)
 

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#25 · (Edited)
Great work. One of the few new members who have taken the time to research anything.

The first thing I would do is remove the cover (5 screws) to the fuse/relay box and pull out the AAM (part #163 545 28 32). NO NEED TO DISCONNECT BATTERY. If you read the recall thoroughly, para. #7 mentions an antenna, which is the RF antenna for the door locks. Check if damaged. If not manipulate the antenna and wiring and at the same time use the remote to lock the doors.

The last reported price I had on the AAM was $250. Call any two M/B dealers, ask for the parts dept. and ask for the price of the AAM (have your VIN # handy). These prices should give you an idea of what the unit will cost, if and when you have it replaced.

Then NOTE page 4 of the recall to see that M/B is allowing dealers ONE HOUR LABOR time to remove and install and reprogram the AAM. M/B cuts the labor times that they allow to dealers, so add apporx 1/2 hr. labor for non-warranty work.

So approx $250 for the AAM and let's say $250 for labor is $500. Then with this approx. cost you can compare it to the price you receive from the dealer to solve your problem. Remember that this replacement can only be done at a M/B dealer and CANNOT be done by an independent mechanic. Hope this has helped you.

Another thing to check is if your Anti-Theft System works. Roll down the driver's window and then lock all doors with the key. Then after one minute of so, open the driver's door using the inside handle. If the alarm sounds then at least you are protected that way, but if it doesn't then you might have to consider the repair, but only within a sane price range.
 
#32 ·
The issue of the resync process only working on the first subsequent button press on the remote is in a few different posts, but I haven't found a post with a resolution or closing remark - has anyone definitively gotten their remote to work again after experiencing this problem on their own, or gotten a clear response from a dealer?

Thanks!
 
#34 ·
I still have the same issue and have search through this forum for any sort of fix but haven't been able to. It appears that most people have given up and just lock and unlock the car via the key instead of the remote. If this is such a wide problem effecting so many people, I am suprised that there hasn't been a recall to fix this issue. Or maybe we should all contact MB to address this problem.
 
#36 ·
I can understand your frustration, but these systems all run on frequency signals and are extremely difficult to track down. In some instances on the dealer can remedy the situation.

My suggestion would be to see if any "B" codes are stored. Only a professional grade scanner will show these codes, not a code reader.
 
#39 ·
Hi everybody, just a new member with an old problem.
I am having it too. Doing all the things as described in the manual and all I get after is just one press and dead again. Funny very funny.
I write to MB about it but I think they will tell me to go to a dealer service. Also I'm not so good in english and not so shure they will understand everything in my mail.
So I offer more of us to write them. May be that is the way to solve our problem.
 
#40 ·
Alex,

No one seems to know what is causing this issue and the ones that had it fixed are not responding. I am having the dealer check out my car as I type this and will post results as soon as I find out. Their initial findings were that the AAM needs to be replaced. Since my car doesn't fall within the effected recall serial number, I have to pay roughly about $500 to $600 to have it replaced. Once it is replaced, I am selling this car so I dont have to deal with this POS car anymore.
 
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