2018 CLA 250 Keyless GO and rear defroster not working
Thread Starter
Newbie
Joined: Apr 2025
Posts: 2
Likes: 0
2018 CLA250
2018 CLA 250 Keyless GO and rear defroster not working
Hi,
I am a new member. I recently bought a 2018 CLA250.
The key turns on the car, but the lock unlock/push button start stop functionality does not work.
I assumed it was a faulty key and got another key made through a dealership. Unfortunately, that did not fix the issue, but the new key does work.
Yesterday, I noticed that the rear defroster doesn't work.
I found some information online that the rear defroster grid also acts as a radio antenna for the key. Is that true?
I used a multimeter to check connectivity between the left and right sides of the grid, and it's not working.
Is there a workaround, or can I somehow bypass the grid to test my remote lock unlock?
Any help would be appreciated.
Thanks!
I am a new member. I recently bought a 2018 CLA250.
The key turns on the car, but the lock unlock/push button start stop functionality does not work.
I assumed it was a faulty key and got another key made through a dealership. Unfortunately, that did not fix the issue, but the new key does work.
Yesterday, I noticed that the rear defroster doesn't work.
I found some information online that the rear defroster grid also acts as a radio antenna for the key. Is that true?
I used a multimeter to check connectivity between the left and right sides of the grid, and it's not working.
Is there a workaround, or can I somehow bypass the grid to test my remote lock unlock?
Any help would be appreciated.
Thanks!
MBWorld God!
Joined: Dec 2019
Posts: 32,667
Likes: 6,417
Hi,
I am a new member. I recently bought a 2018 CLA250.
The key turns on the car, but the lock unlock/push button start stop functionality does not work.
I assumed it was a faulty key and got another key made through a dealership. Unfortunately, that did not fix the issue, but the new key does work.
Yesterday, I noticed that the rear defroster doesn't work.
I found some information online that the rear defroster grid also acts as a radio antenna for the key. Is that true?
I used a multimeter to check connectivity between the left and right sides of the grid, and it's not working.
Is there a workaround, or can I somehow bypass the grid to test my remote lock unlock?
Any help would be appreciated.
Thanks!
I am a new member. I recently bought a 2018 CLA250.
The key turns on the car, but the lock unlock/push button start stop functionality does not work.
I assumed it was a faulty key and got another key made through a dealership. Unfortunately, that did not fix the issue, but the new key does work.
Yesterday, I noticed that the rear defroster doesn't work.
I found some information online that the rear defroster grid also acts as a radio antenna for the key. Is that true?
I used a multimeter to check connectivity between the left and right sides of the grid, and it's not working.
Is there a workaround, or can I somehow bypass the grid to test my remote lock unlock?
Any help would be appreciated.
Thanks!
Thread Starter
Newbie
Joined: Apr 2025
Posts: 2
Likes: 0
2018 CLA250
Not exaclty interfernece
My theory was that if the defroster grid is used as an antenna, if the grid is damaged, then the remote's signals aren't getting picked up.
Is that even possible, or am I completely off base here?
What else can I diagnose? What fuse(s) should I check?
My theory was that if the defroster grid is used as an antenna, if the grid is damaged, then the remote's signals aren't getting picked up.
Is that even possible, or am I completely off base here?
What else can I diagnose? What fuse(s) should I check?
MBWorld God!
Joined: Dec 2019
Posts: 32,667
Likes: 6,417
Not exaclty interfernece
My theory was that if the defroster grid is used as an antenna, if the grid is damaged, then the remote's signals aren't getting picked up.
Is that even possible, or am I completely off base here?
What else can I diagnose? What fuse(s) should I check?
My theory was that if the defroster grid is used as an antenna, if the grid is damaged, then the remote's signals aren't getting picked up.
Is that even possible, or am I completely off base here?
What else can I diagnose? What fuse(s) should I check?
