DAS Troublshooting help needed - PeachParts Mercedes-Benz Forum

cgoodwin · #1 01-01-2025, 10:17 PM

2003 Mercedes W163 ML55

Battery was dying and I made several low battery starts, had to charge for an hour or jump to get the truck going.

Changed the battery to a new battery and used the remote to open the door without issue.

Tried to start car and it starts then instantly dies and the odometer displays "Start Error".

I checked the battery again, poked around, locked and unlocked the car with the remote with no issue and the same issue happened when trying to start.

I tried to resync the key as follows:

Doors closed > Key in ignition to pos 2 > Remove key and quickly hold down the lock button while pressing the unlock button 5 times > release all buttons and press the rear hatch button on the fob once. Put the key in the ignition and start.

This time the alarm went off. Removing the key I find that the remote will no longer lock or unlock the doors at all. Repeated the sync again - same result.

Scanned the DAS module with icarsoft > Code reads "Transponder can not be read"

SO there I am, the transponder can not be read and it does not like the radio remote either. Now what?

Remove the DAS and see if it is wet or has poor connections?

I have only one key and Mercedes says they can not get a replacement as they are on backorder.

Ideas?

TimFreeh · #2 01-16-2025, 11:37 AM

Here's an old thread where my cousin faced and solved a 'start error' problem/symptom on a contemporary W140 S-class. The poster had the same error on a W163 as you now are experiencing.

There was no resolution on the W163 version of the error but I think the background information will be of use to you.

DAS drive authorization of this era is just a silly rube Goldberg style scheme. Problems with this system will send a large portion of these cars to the junkyard as you pretty much need to be a systems engineer to understand and solve problems. Of course even if you can the parts are no longer available.

My cousins problem on the W140 was a blown fuse.

Start Error

cgoodwin · #3 01-17-2025, 09:44 PM

It was actually sorted out today.

I checked the can bus and the values on the high and low sides equaled 5v so I assumed the Can Bus was operating, I was able to get a "Transponder not read" message from the DAS so I was confident it was working.
I contacted a locksmith I work with and he came by. Connecting his software we could see that the DAS could not read the key, we put the key in a reader he has and it also would not read the key.
At this point he programmed another chip to match the DAS and taped it to the not working key, the vehicle responded and started with no issue.
I had him make me a spare key with a transponder and Later I took the faulty key fob apart and removed the faulty transponder and replaced it with the new one.

I am unsure how or why the key transponder failed, but that was the issue.

My locksmith tells me that the most common errors he sees are a module failing and taking down the can bus, then the EAM can not communicate with the DAS and the whole thing crashes. The DAS fills with water and stops working, apparently, all the DAS modules are the same and they can easily be reprogrammed, or the key fails.

He tells me that the flip KEy was a US market thing and a few years ago the factory that makes the flip key had a fire, Mercedes decided not to replace the equipment so the flip keys are no longer available from Merceedes, but the chips are readily available.

TimFreeh · #4 01-18-2025, 10:36 AM

Fantastic! The services of your 'locksmith' are going to become more valuable as these cars age-out.