ML Battery Change, Now Problems! HELP! - PeachParts Mercedes-Benz Forum

DougNJ · #1 01-12-2005, 10:08 PM

Well, The wife left the lights on and the door open in the ML. The battery died and since it is original to the 2000 I figured I would change it out.
Got info on how to do it and things went pretty smooth.....except.....

I have the light for the angle sensor on now, and turning it lock to lock doesn't turn it off. I tried discoing the battery 2 times and trying it. Still stays on.

And

The truck starts up just fine, but as soon as you give it gas it acts as if you arn't even pushing the peddle. Unless you floor it, then it stumbles and misses. Let off the gas and it goes back to a nice idle.

All of this started after the battery change.

HELP PLEASE!

Thanks
Doug

dakat · #2 01-12-2005, 11:42 PM

Doug: You need to find your radio code card, usually in the owners manual. If not call the dealer and give him your vin# and he can give it to you. Your radio will ask you for it. Enter it per the instructions, then turn the steering wheel all the way to the left and than all the way to the right with key in postion 2. This should take care or it! My 430 had the instructions in the owners manual, but I can't find it in my 500 manual. Last resort call the dealer they will usually help you! Good luck!!

Gilly · #3 01-13-2005, 04:27 AM

You have to turn it lock to lock a couple times usually, not just once, so try that and if that doesn't work, then there is some odd coincidence going on here and you'll have to get the codes read. "Light for the angle sensor" I assume you mean the ESP/BAS light? The one that actually LOOKS like a steering wheel is for the tilt steering wheel latch. Just latch it and that one goes off.
The performance problem, hmmmm, could be lots of things, the only one relating to the battery going dead would be losing the crank angle sensor adaptation, the dealer would need to check that out, or could be the MAF sensor or throttle motor, but these wouldn't relate to the battery going dead.

Gilly

DougNJ · #4 01-15-2005, 02:53 PM

Well, I had tried several times going lock to lock and the esp/bas light wouldn't go off. Radio reset fine. The truck would idle out of the drive but as soon as I gave it gas it wouldn't do anything......almost like it didn't even know I was pushing on the peddle. When the peddle would get to the floor the truck would buck once and settle to an idle. No codes either.

MB came and picked it up and after having it all day they said they had to "reprogram the computer". Sounds kinda fishy, they charged me 1.5 hours worth of labor and everything seems to be back to normal.

Seems strange as the only thing that was done was changing out the dead battery with a new one.

Doug

fema · #5 01-27-2005, 04:24 PM

I recently had the battery jumped and changed, then my remote keys wouldn't work - I was told the AAM module needs to be replaced and the keys reprogrammed. Your problem sounds similar, but not as harsh as mine cost wise - they tell me $500 for the new part, plus reprogramming the keys. I'm still not sure I believe what they tell me as far jumping the car can cause the "sensitive" electronics to blow - I plan on persuing this further with a couple of different dealer service managers and see what they say. I'm still using my valet key to run in the meantime.

Gilly · #6 01-27-2005, 05:15 PM

Any of your keys should start the truck, sounds like just won't unlock it. Has anyone tried resynchronizing your keys?

Gilly

fema · #7 01-27-2005, 06:58 PM

Gilly - the remote control keys will start the vehicle for about 1 sec, then it dies. A dealer in Denver did (so they said) try to reprogram the keys unsuccessfully. And this bit about replacing the AAM came from them - a service advisor brought the car back to the mechanics - as I said, I plan to press the issue. With Denver 3 hours away, I just haven't gotten to it.

Any further advice you have would be appreciated! I was going to try another dealer as well - see if I get the same answer.

Gilly · #8 01-27-2005, 07:33 PM

There is nothing "magic" about the valet key. It incorporates DAS to start just like the remote keys do. The only difference is no remote lock/unlock/panic functions. The AAM is used to validate the valet key, so to say the AAM is the cause is unlikely. There is nothing they can do to "synchronize" DAS, the synchronization is for the lock/unlock features, either the key works to start the car or it doesn't and nothing they can do will change that, unless someone got into the AAM with the SDS and disabled/enabled keys. It sounds improbable, but maybe these 2 keys are bad, no idea why a dead battery would cause these 2 keys to go bad. Also I'll point out that the keys will work for starting the vehicle with no battery in the key at all.

Gilly

fema · #9 01-27-2005, 07:42 PM

Gilly - that is very interesting! My remote keys do work to lock/unlock - actually, my spare remote stopped working and I'm guessing the battery need replacing. I was told something like the remote keys have a chip that is read by the vehicle, and somehow this is a security feature(???) - to refresh your memory of my story, this all began afterr AAA tried a jump start, and the battery being replaced the next day at my local shop.

I appreciate the ammunition you have given me, and have to ask one more thing - are you an MB technician? I thought I read that somewhere on this forum.

regards!

Gilly · #10 01-27-2005, 07:54 PM

USED to be an MB tech, up to a couple years ago almost. I should start a thread on life after MB.

OK, on the one where the remote-only doesn't work, THAT needs the battery, then probably just needs to be resynchronized (instructions in the owners handbook).

YES there is a chip in each key, this is part of DAS (driver authorization system). It is read by that chrome collar around the ignition lock (what the key goes in to). If the collar picks up the correct key (feeds info into various computers and eventually the engine control module) then it will allow the engine to start. Notice I said START not CRANK. The engine will crank or briefly start but won't remain running. The engine can act this way because of other problems too, such as a bad fuel pressure regulator or fuel pump, so diagnosis is critical here. Often if the key or other part of the DAS system is faulty, you will get a message when cranking in the odometer that says "start error", so look for that. Since you can start the car with the one "valet" key, we can assume the "truck" itself is fine, and probably a bad key or two is the fault, but again what led up to your problem (jump, then repl 12V battery) makes no sense, coincidence???
Again the valet key works with DAS like any other key, nothing different in what is required to start the engine. Just no remote unlocking feature.
Look for the "start error" message, if you're not getting that there is another way to determine if DAS is releasing the control module to start the engine that I can tell you about.

Gilly

fema · #11 01-27-2005, 08:14 PM

Gilly - no "Start Error" in the odometer display, I just tried it. The car does crank, and run for a second. Now what?

Gilly · #12 01-27-2005, 10:11 PM

Between the foglight and low range (?) switches there is a small LED. I think it blinks on and off when the truck is locked. If you unlock the truck and get in and just turn the key to "on" (just before "crank" position, you should see a very short blink of that LED, that means DAS is authorized is start. Compare what happens with the one key which will start the engine (the vaket key) with one of the remote keys. I am still betting it's keys.

Gilly

fema · #13 01-28-2005, 06:26 PM

Gilly - had to run out last night, now I'm back.

Tried your suggestion - the valet key causes the short blink of the light when inserted in the ignition and not turned on, as well as when turned to on. Neither remote key will do that. Now what?

I mentioned before that my spare remote doesn't lock/unlock, and has been used little since new - does this make sense, lack of use will render the battery dead sooner than my other everyday remote?

Gilly · #14 01-29-2005, 04:31 AM

It sounds to me like the remote key transponders are both bad (those are the computer chips inside the key,, the ones that require no power (battery), the valet key transponder must be fine.
On the one remote that doesn't work, I guess it's a moot point if it won't start the truck, but it seems like if you have a single key that hasn't been used to lock/unlock for a long time, it may lose synchronization, but this won't have any bearing on starting the truck, it should always work for that.
Gilly

fema · #15 01-29-2005, 12:27 PM

Gilly - Ok then, I will go to the dealer armed with this info, and see what they say. It may be a couple weeks before I can get to Denver, but I'll report back to you and the forum here - thank very much!