Today I had my first real problem with my 2005 roadster. I tried to unlock the door with the key fab, and the car did not respond. I figured the battery was bad in the fob, so I got my spare. It didn't work either. I tried using the key to unlock the door, but that set off the alarm, so of course the engine cuts out too. So I had the car towed to the dealership, and they told me that the security module needed to be replaced at the tune of 600 dollars. AND that it would take 4-5 business days to get the part. So I get a rental car, and hours later, I return to the dealership to get something out of my crossfire. They had taken the crossfire to their back lot (I guess to store until the parts came in), and I noticed a large gap between the back hood and the convertible top. So the "mechanic helper" comes with the key fob, and unlocks the car with the fob! Tail lights flash, and bingo, the car is unlocked. I was shocked! So I took the key, started the engine, all was fine.....except for the convertible top. I figured someone had not raised the top properly, and went to open the trunk to lift the trunk divider, and the trunk would not open, it seemed to be stuck. At that point I was confused! After talking to the service manager, he did not seem to know what was going on, and I don't know what to do now. The mechanic that works on the crossfires was gone for the day so I was unable to talk to him, At this point, I'm thinking that a wire or something was loose, and the take down to find out what was wrong fixed the problem, or do I really need to spend 600 dollars for a new module.

ANY input would be greatly appreciated!

 

I had a similar problem with starting the car and my top. Key fob wouldn't work, opened the door with my key, but security system did not go off, and the car wouldn't start. Turned out the battery was dead, so I jumped the battery, started the car and took it to the dealer. The dealer checked the car and found no problems.

This happened two more times, and the third time I found that the top also would not operate. I took it to my dealer the third time, he told me that he had dropped his Chrysler deaklership, and would no longer warranty the car. The next closest dealer did not have the equipment (computer module to run diagnostics on the Mercedes engine) to service the car. The next dealer (Burger Chrysler in Terre Haute, IN) had the equipment, ran the diagnostic and found that the convertible ram had bound up. When the ram had bound up, it also took out the computer module for the top and was draining the battery through the motor on the ram. Final cost $800 - $1,000 for a new ram, new battery and new module for the top (not the security system). Fortunately, everything was covered under warranty.

I later found out that the dealer I had bought the car from (new), also had not bought the chip to run diagnostics on the car. That's why he was never able to find out what the problem was originally.

lesson - make sure your dealer has run the diagnostic and knows for certain what the problem is. Not all Chrysler dealers, even the ones that sold them, can service them.

naughteven

 

That's the thing. I don't think it is a problem with anything draining the battery because when I started it with the alarm going, it started right up. And when I started it later in the day when everything seemed to be working fine, it started as it should. I'm not sure what to do. The dealer says it might be an intermittent problem. My concern is that I may be paying 600 for something that is not going to fix any problem, or that the problem may have been a loose wire that was fixed when they pulled the unit.

 

As long as some of the other members have used this guy and have had good results, I'd go with it. He has to have the right module for his computer to analyze your car and if he has that module, he's probably telling you what your car is telling him. The dealership I bought my car from (new) didn't have that module, and because they had to warranty the car for me, just strung me along until they let go of the dealership. Just identify the location where you want to have the car serviced, and the dealership you went to, and some of the forum members in that area, may be able to give you some specific recommendations.

By the way, the module for my top was about $600.00, so the price sounds like it's in the Ball Park.

naughteven

 

these cars are voltage sensitive. Either have the dealership check the battery for a dead cell, or take to someone who can, like an auto zone. If there is any kind of weak voltage it can cause these problems. Battery life is about 5 yrs depending on usage, some don't make it 3 yrs...this is a cheap trial and error...I would put a new battery in, it's time for one anyway....good, luck, but don't spend the $600 yet...doubt that is the problem...Dennis, you might have bound up the 'vert with low voltage as well, if top wasn't moving at the speed it was designed for...just a thought.

 

Could be! Fowler Motors in Fowler Indiana (yes, that was their name as well) told me I had a dead cell in the battery and replaced it. That was the first time I took it in for warranty, and I didn't know then that they couldn't run a diagnostic on the car. That was during the winter, and I didn't put the top down until Spring and found that it would not retract.

However, you are correct. I would expend all the other avenues before I would spend the $600, and another opinion from an experienced dealer wouldn't hurt either.

 

Thanks guys!
I am going to take your advice and ask them to change the battery, like you said, I'm due, as the battery is 5 years old.

I have always taken the car to La Brea Chrysler, in Los Angeles because it is close to my home, and they did some warranty work on it before and all came out ok. But, I don't have a lot of confidence in them because of an incident with my brakes last year. They told me that I needed new rotors$$$$, and when I told them I wanted to take it to another mechanic first and get a second opinion, suddenly they were able to "save" the old ones. Go figure. I am looking for a good mechanic, and after reading the posts here for 2 days, I see that many are using MB mechanics. There are lots of those around where I live. Any suggestions as to what a MB mechanic would need to service a XF?

 

There are a lot of Forum members in OC, so a number of them have their cars serviced in the area. Also, since you have already had some questionable experiences with La Brea Chrysler, I think I definitely would look at another Dealer. I've never used a Mercedes mechanic, but I think that JaneBridges in Vincennes, IN uses one on her racing car. You might PM her and see what her experiences are.

 

I had a similar problem the other day. Fob didn't work so I opened the door with the key. Started the car and then because the fob was in the ignition it reprogrammed itself. Went to lock the car 10 minutes later and the fob worked fine. This is the second time that it's happened to me and the first time neither fob worked but I was always able to start the car. I figure the BCM had an electronic hiccup of some sort. The other time it happened was about a year ago.

 

I had an issue with my 05 as well. I drove it to work and when I was leaving that afternoon I noticed the lights didn't flash when I tried to unlock it. I tried using the key to open the door which set the alarm off. Thankfully it was late in the day so there weren't many cars in the parking garage. (note, the alarm is plenty loud!) I tried everything but the alarms pretty much overrides the entire system so I was stuck. I had it towed to the local dealership and they said the door alarm module needed replacing. Luckily mine is still under its warranty. Its been about a month 1/2 and no problems so far. Hope this helps anyone else facing this problem.

 

Well, here's the old rookie with a stupid question. Some of you have mentioned the alarm going off. I've had my Roadster a little over a week and I've been trying to figure out the security system from the manual.

1. Is the alarm automatically turned on when you lock the car with the fob or do you have to manually turn it on?

2. What triggers the alarm?

3. Concerning my anti-tow switch located on the console. I notice, when I lock the car, that the red light continually flashes on and off. Does this mean that the anti-tow mechanism is on?

 

Learnin, I'll take a shot at answering your questions, although I'm far from being an expert.....

1. The alarm is activated 10 seconds after you lock the car using the FOB. It's automatic.

2. In the roadster with the top down, the alarm will be triggered if someone attempts to open the doors by reaching inside and pulling the door handles, or tries to open the hood or trunk. If they try going into the center console or glovebox the alarm will also sound. Of course, with the top up the alarm will sound if the doors or trunklid are forcibly jimmied open. The alarm will also sound if the car is raised for unauthorized towing, unless the tow-away switch has been pushed to deactivate.

3. The blinking light on the tow-away switch means the security alarm is armed as described above.

Also, the alarm will sound if either or both battery cables are disconnected while the car is locked and the system is armed. No need to ask how I know that one.

 

Thanks for this info, Blast Chamber. I appreciate it. How does one shut the alarm off if it is triggered? Or does it go off automatically after a few minutes?

 

I believe it turns off automatically after 3 minutes or so, but it is so loud that I couldn't imagine waiting that long. Try pushing and holding the PANIC button on the FOB, and if that doesn't work put the key in the ignition and start the car. That should do it. Disconnecting the main battery doesn't help as the alarm has a separate power source buried somewhere in the firewall area.

I don't know what year your roadster is, but if your alarm starts going off at random and you still have the original battery that came from the factory (some of them are 6-7 years old), that is a sign that the battery needs to be replaced. These cars do some strange things when the battery ages and the voltage starts getting low. I'm planning on replacing my 6-year-old battery within the next month, although so far I've had no problems.

 

Thanks. That's good to know. I have a 2007 Roadster...three years old in July...I figure it's the factory battery.

 

Alarm problem has happened to me twice. First time tried to start car with alarm sounding and car locked down and had to be towed to dealer. Second time, with alarm sounding, popped the hood and with a #5 wrench, removed the battery cables. Alarm stopped and replaced after a minute, car started up and key fobs both worked. Who knows!! I carry the wrench iin the pocket of the drivers door just in case.

 

my tow-away alarm randomly prevents starting my car, I am not able to deactivate it, if I let it sit for 1/2 hour or so I can deactivate it and start it, what gives?

 

You may have a bad sensor setting off the alarm (I have NO idea where the sensor(s) are.)

But first, I"d look at the battery. How old is it? How do the battery cable terminals look? You want a reasonably new battery and clean connections between the battery and cables.
If yours is a white Varta battery, it's original. Replace it now, today. THEN see what you end up with. As doc says, these cars are VERY voltage sensitive.

 

Thanks, the battery was the original, I change it this morrning hopefully that cures the problem