I've read DFC's posts, but have a slightly different scenario..

Car (an 02 with 9k miles) was on the top floor of a garage all day (exposed). Weather - misty / rainy. Get home and unlock the car. Get in and insert key into ignition - nothing. Key will not work. No action. It will not move. But, the key will lock and unlock the car. The battery was fine - lights worked. I can even use the summer mode and put all the windows down with the key.

I hit roadside and the car connects to MB. A tech did a diagnosis and pronounced the battery fine. He thought the ignition switch went bad since the keys still worked. They had to be in sync to do everything else. They sync off the ignition. They will not dispatch roadside since they can't do anything and just order a tow truck.

Meanwhile, I went through the fuse box and take out and check all ignition related fuses. No problems. I've unlocked and locked the car about 10 times by now as I go to make phone calls etc. Still will not start. I think about breaking the key in the ignition switch to make sure they take out the culprit but decide not to.

4 hours later (and two trunks) the car is off to the dealer. Since the car was locked in park it had to be dollied out of the garage by a special rig and then put on a special flat bed to handle the suspension. I chose not to watch.

I go to the dealer to drop off the key this morning. The car was left in the customer parking lot. I'm concerned since they still have to get it into the shop and it is locked in park. I try the same key and the car works. Starts right up.

Dealer will look into it later today.

Thoughts?

The last time a C-calss did this to me it proved terminal such that MB now owns that car.

 

I think the car cannot pick up the infra-red signal from your key. This happened to my friend's E55 once. When you put the key on, can you hear anything? 'Cause normally when you put the key on, you can hear a short motor sound, right?

 

No response when key was inserted. I also cleaned the sensor windows and pushed/manipulated the starter side as much as I possibly could.

If it is the IR pick up then it is failing (which is more or less the roadside tech's diagnosis). I'll have to see what service decides to do.

 

sounds so queer that i don't know what to tell ya... :o

 

1st question, BOTH keys?

MB did have a "series" of bad keys (identifiable by the code stamped on the side) these keys would work fine and then get out of sync with the car. There is a TSB for that issue.

Remember the keys (and car) have BOTH IR and RF.
Some functions overlap, some are singular. When you open the car from 30 feet you are using RF only, when you open the windows "all down" by pointing at the door that is IR only.

My guess though, bad IR receiver at the ignition.

 

I think the dealer's conclusion to the issue was a faulty ignition module w/in the car; and that caused the loss of sync w/ the keys. Hopefully, the problem is minimal on JRF's car.

What's this "summer mode" or "all windows down" function you guys are talking about? How do you do that?

 

Only have one key right now - wife has temporarily misplaced the other. The key was in sync and then worked the following day. I had the keys replaced on my C240 (bought back). Although I had the first C32 out, my keys are outside the previous key replacement window.

Regular service has struck out so the car was sent to the team leader / amg specialist. I should find out today if they have any leads.

I've had problems with the radio/nav failing (no power) in the past. It was so intermittent that there was no fix. I'd guess I have a short at a common power point but the radio/nav did get power (by way of teleaid) to make the call for roadside assistance. The ignition also worked when the radio/nav failed.

Summer mode - go to within 5 feet of your car. Push and hold the unlock button. It takes anywhere from 15 seconds to 45 seconds to start the process - all windows open as well as sunroof. Hit and hold lock to close everything. Lets you air out a hot car on summer days without having to get into it.

 

Dealer thinks it is the one key but has no explanation why. I'm scheduled to talk to the mechanic before I take delivery though since I'm going to document everything that happened on the service slip when I pick up the car. When I had a C240 bought back under the lemon laws we did a similar dance. When MB can't or will not authorize a proper fix on the first visit they get nervous when you come back 2-3 months later.

Since the IR and RF in the key worked, I don't see how it is the key. Granted a key is much cheaper than a new ignition module. The car was elevated in service priority which means (I think) the regional rep had to sign off /authorize the fix. Unfortunately he does not know how the cars work based on my past experience with him.

The key was in sync and working. Base don my reserahc the ELCODE system has a two stage process - the IR exchange that should work with a key that has a dead battery and then the "calculation" phase to decide whether to start the car. After it starts you go to phase three and the reprogramming, which you can't do with a dead battery. Since the ignition never unlocked (never did anything) per the Roadside diagnosis I am convinced I have a bad ignition module. Replacing keys is what they did with my C240 which also would not start.

They will have the car another week or so since they pulled the side of the bumper off when they towed it. Hopefully it will fail again this next week when they have the car in the shop.