Remote FOB needs reset every day even with new battery
Thread Starter
Member
Joined: Sep 2007
Posts: 210
Likes: 16
From: Sydney Australia
W205 C250BT & R320cdi-L V251 (sold c220 cdi Elegance)
Remote FOB needs reset every day even with new battery
Hi,
Recently I have replaced my CR2025 remote battery as the W205 was reporting low battery.
Subsequent to that I am finding that i have to remove the remote battery and re-install it for it to become visible to the car.
It will immediately work, but again repeat with the same issue in a day or 2.
Any thoughts on what may be the cause?
Thanks in advance.
Recently I have replaced my CR2025 remote battery as the W205 was reporting low battery.
Subsequent to that I am finding that i have to remove the remote battery and re-install it for it to become visible to the car.
It will immediately work, but again repeat with the same issue in a day or 2.
Any thoughts on what may be the cause?
Thanks in advance.
Member
Joined: Oct 2019
Posts: 145
Likes: 32
From: Cheshire UK
C200
The difference is the thickness - 2025 is 2.5mm thick, 2032 is 3.2mm thick.
MBWorld God!
Joined: Dec 2019
Posts: 32,515
Likes: 6,350
Member
Joined: Oct 2019
Posts: 145
Likes: 32
From: Cheshire UK
C200
MBWorld God!
Joined: Dec 2019
Posts: 32,515
Likes: 6,350
no worries at all thanks for confirming for us all. Do you think you want to switch to CR2032? I am considering if it is worth it with the extra thickness for longer battery life which means the cover might stick out a little.
Trending Topics
MBWorld God!
Joined: Dec 2019
Posts: 32,515
Likes: 6,350
Not sure, CR2025 is what my dealership puts in back when I had PPM here in Canada and so that is what I did. I don't recall seeing it specifically saying it is CR2032 but that is probably because I didn't actually check before putting it in.
MB World Stories
The Best of Mercedes & AMG
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)
Verdad Gallardo
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
Out Of Control!!
Joined: Nov 2018
Posts: 11,467
Likes: 5,356
From: San Francisco Bay Area
2019 C63CS
MBWorld God!
Joined: Dec 2019
Posts: 32,515
Likes: 6,350
Interesting, let me grab my key and check, if there are no changes for the facelift I am surprised why my dealership puts CR2025 in it then. Does the new key fob consume more power or they design it so a CR2032 will fit better? I would think the new key fob actually consumes less since the key deactivates during inactivity but not sure when it is active it actually consumes more than the older key.
MBWorld God!
Joined: Dec 2019
Posts: 32,515
Likes: 6,350
Out Of Control!!
Joined: Nov 2018
Posts: 11,467
Likes: 5,356
From: San Francisco Bay Area
2019 C63CS
In that case I'd recommend trying a new battery. Unfortunately with batteries you never know how long they've been sitting on a shelf and whether they were always stored at proper temperatures. It's not unusual for new batteries to be bad already. I also believe the CR 2032 is more common than the CR 2025, so the latter might be sitting on shelves longer.
MBWorld God!
Joined: Dec 2019
Posts: 32,515
Likes: 6,350
In that case I'd recommend trying a new battery. Unfortunately with batteries you never know how long they've been sitting on a shelf and whether they were always stored at proper temperatures. It's not unusual for new batteries to be bad already. I also believe the CR 2032 is more common than the CR 2025, so the latter might be sitting on shelves longer.
Out Of Control!!
Joined: Nov 2018
Posts: 11,467
Likes: 5,356
From: San Francisco Bay Area
2019 C63CS
It seems his key fob stops working within a day or two, so if the key fob no longer communicates with the car properly then there won't be a low battery warning. Now it could also be an electrical fault in the key fob because it was opened up to change the battery. Maybe a bad contact or something. If a new battery doesn't do the trick, I'd try to clean it out with some contact cleaner spray. There might be debris in it.
MBWorld God!
Joined: Dec 2019
Posts: 32,515
Likes: 6,350
It seems his key fob stops working within a day or two, so if the key fob no longer communicates with the car properly then there won't be a low battery warning. Now it could also be an electrical fault in the key fob because it was opened up to change the battery. Maybe a bad contact or something. If a new battery doesn't do the trick, I'd try to clean it out with some contact cleaner spray. There might be debris in it.
Thread Starter
Member
Joined: Sep 2007
Posts: 210
Likes: 16
From: Sydney Australia
W205 C250BT & R320cdi-L V251 (sold c220 cdi Elegance)
Thread Starter
Member
Joined: Sep 2007
Posts: 210
Likes: 16
From: Sydney Australia
W205 C250BT & R320cdi-L V251 (sold c220 cdi Elegance)
In that case I'd recommend trying a new battery. Unfortunately with batteries you never know how long they've been sitting on a shelf and whether they were always stored at proper temperatures. It's not unusual for new batteries to be bad already. I also believe the CR 2032 is more common than the CR 2025, so the latter might be sitting on shelves longer.
MBWorld God!
Joined: Dec 2019
Posts: 32,515
Likes: 6,350
Is the exact symptoms happening on your other key? If so it might have to do with the EIS module in your vehicle if I remembered what you call that. Usually it is just a software issue if not a hardware replacement might be necessary.
Thread Starter
Member
Joined: Sep 2007
Posts: 210
Likes: 16
From: Sydney Australia
W205 C250BT & R320cdi-L V251 (sold c220 cdi Elegance)
I tested both batteries in a tester (identical to this https://www.amazon.com.au/Dlyfull-Un.../dp/B07DPLD6KB ) and both batteries reported well into the GOOD. Infact they were only a notch different.
How ever the issue does not occur with the other FOB, so my next test is to swap batteries and rule out a FOB issue and hopefully close this off as a fickle battery problem.
MBWorld God!
Joined: Dec 2019
Posts: 32,515
Likes: 6,350
Good point!
I tested both batteries in a tester (identical to this https://www.amazon.com.au/Dlyfull-Un.../dp/B07DPLD6KB ) and both batteries reported well into the GOOD. Infact they were only a notch different.
How ever the issue does not occur with the other FOB, so my next test is to swap batteries and rule out a FOB issue and hopefully close this off as a fickle battery problem.
I tested both batteries in a tester (identical to this https://www.amazon.com.au/Dlyfull-Un.../dp/B07DPLD6KB ) and both batteries reported well into the GOOD. Infact they were only a notch different.
How ever the issue does not occur with the other FOB, so my next test is to swap batteries and rule out a FOB issue and hopefully close this off as a fickle battery problem.
