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Car alarm & door lock chirp newly inoperative

3K views 5 replies 3 participants last post by  Sleeper Benz 
#1 · (Edited)
DAS quick test brought up this 'F' in Rear SAM module.
Rear SAM fuses & relays checked, #8, a 7.5a fuse indicated to be assigned to Alarm horn (H3) in WIS was not blown. :angel
Looks like I'll need to remove driver's side fender liner to access H3/1 which lives on back of wheel arch according to Starfinder. This issue started just a couple days ago after driving through severe downpour & flooded streets. I've read it's PCB will likely be corroded beyond repair so will probably just need to be replaced if I can find one. I've also read that this module contains it's own non-replaceable batteries that eventually fail by design so I guess replacement really is my only option. Has anybuddy had this issue crop up & if so am I on the right track for diagnosis or should I keep digging for other possible solutions? Thanks in advance for any/all advice, information &/or suggestions! :grin I think part # is A2118200385
 
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#3 · (Edited)
Thank-you konigstiger! I finally dug into this & found best overall price for part #A2198203226 on Amazon for $168 w/tax+shipping. When first plugged into 3 wire connection plug, new part's chirp sounded much different than original. DAS revealed it to have been originally coded for 'Japan w/o tilt' so I coded it properly to 'USA with buzzer' That restored it to chimes like original. DAS refers to this part as an ATA (Anti-theft alarm) & can be reflashed via control unit adaptation found in Rear SAM control unit. I was curious as to what made original expire & have read that it has internal batteries & since old replaced with new, decided to dissect via hacksaw. I took a few pictures of what I found:
This is the speaker side:


This is underside of PCB:


This is the PCB side where batteries are located:


This is original part #:


This is the updated part #:



I thought I took a picture of housing this siren is mounted in but I apparently forgot to. It sits mounted underneath engine bay fuse box & is right next to driver's side rooftop water drain tube. That water drain was starting to trigger some rust to breakout in floor of housing on mine so I sprayed it with undercoating in rusty areas before reinstall. I was able to access by pulling rear half of driver side front wheel liner. I didn't have to remove tire to get to 10mm plastic nuts that hold liner in place but did have to jack up front of car so wheel off ground then turn steering wheel to full right lock. This job was a snap. DTC erased & easily cleared & now my chirp & anti-theft siren has been restoritized!
 
#4 ·
Thank-you konigstiger! I finally dug into this & found best overall price for part #A2198203226 on Amazon for $168 w/tax+shipping. When first plugged into 3 wire connection plug, new part's chirp sounded much different than original. DAS revealed it to have been originally coded for 'Japan w/o tilt' so I coded it properly to 'USA with buzzer' That restored it to chimes like original. DAS refers to this part as an ATA (Anti-theft alarm) & can be reflashed via control unit adaptation found in Rear SAM control unit.
So you need a STAR unit to reprogram this unit for USA or was there a trick you did with the SAM unit?

I'm replacing my 2004 w211 siren with a used unit that came out 2009 Mercedes Benz CLS550 AMG W219. Hopefully that will be USA programmed and WORK? I just figured they were all the same.
 
#5 ·
I believe siren hardware is same for all but internal EEPROM programming of siren can be flashed differently for different regions of world apparently. It will work right out of the box w/o any software intervention but may sound different based on how it's coded to vehicle it originally came from. I was considering fishing one out of a salvage car until I read about those internal batteries that are soldered onto PCB of siren. My w211 is a 2005 MY built in 4/2004 so internal batteries last about 13 yrs or so it would seem. While it's necessary to use SDS to reflash siren's EEPROM settings if not happy w/ how it sounds by default, it's not necessary to get it to work as is, plug & play. I reflashed mine mostly because I wanted to see how process works in SDS for reflashing EEPROM via control unit adaptations. My logic was better to practice procedure on something harmless first like ATA siren in case I brick it before graduating to something critical like a tranny or engine control unit.
 
#6 ·
Thanks for the update. I also just installed a replacement siren unit that works well so far. It has a triple "beep" sound when activating and a high pitched sliding Hi/Lo siren. Not the double "chirp" activation sound I'm used to hearing on typical after market alarms.

I've noticed that all these later model 2004+ siren units have the same electrical connectors on them, but they do vary in shape somewhat over the years.
 
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