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Hi - new to the forums as I've just picked up a 2003 E240 (Australia) and have a few small (I hope) issues to sort out.
I noticed the key fob had no range and thinking it was just batteries I replaced both to no avail. I then started reading the forums and realised that it could possibly be a much bigger issue. I have tested the infrared lock / unlock and it works fine (confirm IR signal with phone) as long as I am standing at drivers door. This afternoon however it was working via RF because I could lock / unlock from all around the vehicle and confirmed by covering IR lens on key fob while locking / unlocking. When I got home this evening however it had stopped working again. I checked the antenna amplifier fuse in the boot (fuse #8) and it was fine. I can't find the AAM unit to check if the antenna is connected properly but I now don't know where to start.
So this afternoon it's working again. I removed the rear interior panel and removed power from the green antenna amplifier and sure enough the key fob stopped working. I plugged power back in and it works again. I have a feeling the issue might be related to the power feed to the amplifier.
So this afternoon it's working again. I removed the rear interior panel and removed power from the green antenna amplifier and sure enough the key fob stopped working. I plugged power back in and it works again. I have a feeling the issue might be related to the power feed to the amplifier.
This morning I went out to car and key fob would unlock, car hadn't been touched since it was working last night. Where is the key fob receiver in the W211, is there an antenna / RF coax connection I can check? The antenna amplifier looked fine. Wondering if there's corrosion at the RF connector.
02-16-2022, 05:57 AM
