W203 C200k M111 in 2001 - Mercedes C200k W203 - remote control problem

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Thu 4 Sep 2014 03:21
W203 C200k M111 in 2001 - Mercedes C200k W203 - remote control problem - jsiu

I am driving a 2001 C200k W203 (original owner since 2001). In the past six months, I need to point my car key remote to the driver door infra red sensor to unlock the car. In the past, I can unlock the car using the car key at least 10 feet away. I replaced the two button batteries CR2025 inside the key but no improvement.

The above situation applies to both of the two car keys originally supplied by Mercedes.

I further discovered that fuse 8 at the boot was blown and the alarm siren was failed. However, the fuse 8 blown again after I replaced it with a new one. Apparently, there is a short somewhere in the circuity. How should I trouble shoot further?

Looking forward to your advice and thanks in advance.

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Thu 4 Sep 2014 09:09
W203 C200k M111 in 2001 - Mercedes C200k W203 - remote control problem - elekie&a/c doctor

Have you disconnected the siren completely?A short circuit in the siren will blow the fuse in the boot. If the fuse continues to blow,then there could be a fault with the rf receiver located in the roof,above the rear window.The fact that the locking only works close to the door means the system is working on infra red only and not the radio frequency system.

Edited by elekie&a/c doctor on 04/09/2014 at 09:09

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Thu 4 Sep 2014 13:45
W203 C200k M111 in 2001 - Mercedes C200k W203 - remote control problem - jsiu

Thank for guidance. I do not have any automobile DIY experience. May I know what is the alarm siren located? Is it somewhere inside the engine compartment?

Thanks for your help in advance.

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Thu 4 Sep 2014 18:32
W203 C200k M111 in 2001 - Mercedes C200k W203 - remote control problem - elekie&a/c doctor

The siren is located under the car ,by the left front chassis member,behind a removable cover.The car needs to be on a lift or jack for access

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Fri 5 Sep 2014 03:08
W203 C200k M111 in 2001 - Mercedes C200k W203 - remote control problem - jsiu

Thanks a lot.

www.youtube.com/watch?v=BzmpeK1TFfw

I eventually found the above in youtube which may be useful to other forum readers too. The internal battery of the siren should be dead after 13 years usage since 2001 and causes a short to the ground.

Excellent for your knowledgeable advice. The next step for me is some donkey work. BTW, if I want to replace a new siren, how can I check the MB part number for the siren? Of course , if it is too expensive for a new siren, I simply don't install siren any more. I think nobody border to steal my 13 years old W203.

Thanks again.

Edited by jsiu on 05/09/2014 at 03:08

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