CLS63s - Keyless Entry Issues
Thread Starter
Junior Member
Joined: Jan 2016
Posts: 35
Likes: 3
2015 CLS63 AMG S-Model
CLS63s - Keyless Entry Issues
Hoping someone can help me. I have a 2015 CLS63s and just started having some keyless entry issues after leaving the vehicle parked ~30 days (indoor parkade).
Issues started off, wasn't able to use the "Close and Lock" button on the trunk, however could use keyless to open it. "Close without lock" button works, and pressing the "Clock and Lock" button interrupts a close, so there's no connection issue. Problems progressed to not being able to open the trunk using keyless intermittently, to almost always not working now (can't detect FOB). I'm also noticing the issue occasionally trying to unlock rear doors, and front passenger now using keyless. One thing that's odd is if I'm driving, and get out, I can always almost certainly lock the doors using keyless by touching the handles (detects fob).
Replaced battery in FOB, no change. Vehicle battery replaced 8 months ago.
With the intermittent changes in behavior, I'm assuming it's not isolated to any specific antenna in the handles specifically, but probably the keyless module, FOB, or something else? Thnx in advance!
Issues started off, wasn't able to use the "Close and Lock" button on the trunk, however could use keyless to open it. "Close without lock" button works, and pressing the "Clock and Lock" button interrupts a close, so there's no connection issue. Problems progressed to not being able to open the trunk using keyless intermittently, to almost always not working now (can't detect FOB). I'm also noticing the issue occasionally trying to unlock rear doors, and front passenger now using keyless. One thing that's odd is if I'm driving, and get out, I can always almost certainly lock the doors using keyless by touching the handles (detects fob).
Replaced battery in FOB, no change. Vehicle battery replaced 8 months ago.
With the intermittent changes in behavior, I'm assuming it's not isolated to any specific antenna in the handles specifically, but probably the keyless module, FOB, or something else? Thnx in advance!
Thread Starter
Junior Member
Joined: Jan 2016
Posts: 35
Likes: 3
2015 CLS63 AMG S-Model
Just pulled up the workorder, it was only the main battery that was replaced. I'm wondering if I'd be able to swap the AUX myself to keep costs low. Seeing references to a "re-learn" on the workorder for the main, hopefully the AUX could just be swapped easily. Side Note: The main battery was replaced because eco start/stop didn't work for 2-3 years, no errors or faults, dealer said everything was fine. Replaced it on my own request since I noticed my cabin lights were dimming weird with RPMs, and as soon as it was replaced, ECO start/stop started to work again like when the car was new, lol.
Last edited by Zhariak; Apr 24, 2024 at 07:44 PM.
Thread Starter
Junior Member
Joined: Jan 2016
Posts: 35
Likes: 3
2015 CLS63 AMG S-Model
So, went to check the auxiliary battery, and it's not where it was supposed to be, lol. Opened the trunk and removed the 2 covers below, and I was expecting it to be on the right side (like where it is in YouTube videos), but it nothing was there, lol.
Also, minor update, the back doors are working now (unlock/lock with keyless), but the trunk still won't allow the button "Close and Lock" as the FOB isn't detected.
Does anyone know where the module is for this, so I could check the connectors? I had some vehicle work done around the time it stopped working and I'm wondering if a connector came loose.
Also, minor update, the back doors are working now (unlock/lock with keyless), but the trunk still won't allow the button "Close and Lock" as the FOB isn't detected.
Does anyone know where the module is for this, so I could check the connectors? I had some vehicle work done around the time it stopped working and I'm wondering if a connector came loose.
