Mercedes-Benz Forum banner

Key Fob Not Working From Distance, Intermittently from small distance

12772 Views 3 Replies 2 Participants Last post by  rudeney
Hello all


Remote does not lock/unlock from distance.

I have to hold it very close to passenger side door handle to lock/unlock. Driver side rarely responds.

Recently noticed if I stand very close to the driver side door to block all light, and hold the key on the handle, it works.

The red LED lights up after pressing lock/unlock button. No light after pressing trunk button.

I have checked the infrared ray using a camera. I see it responds when I press lock/unlock buttons.

Please help.
1 - 2 of 4 Posts
Check fuse #8 (in the trunk). If its blown and continues to blow, then you likely have a bad ATA (alarm) siren. It shares fuse #8 with the antenna amplifier module. You need to replace the ATA siren or at least disconnect it to keep the fuse from blowing. It's located under the fender shroud behind the front passenger wheel. If the fuse is not blown, then your antenna amp is totally dead. It's expensive and very difficult to replace - it's attached to the top of the rear windshield.
If RCL works at all, the am is not dead, but it is likely detached from the glass so that it no longer makes contact with the embedded antenna wire. It is possible to remove and re-attached the amp module, but it requires removing the headliner to get to the amp, then removing it and re-attaching is using a special adhesive.
1 - 2 of 4 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.