2006 C350 - Key Fob Lock/Unlock not working
Thread Starter
Junior Member
Joined: Oct 2021
Posts: 16
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From: California
2006 C350
2006 C350 - Key Fob Lock/Unlock not working
Trying to figure out why my key fob stopped locking and unlocking the doors/trunk. Starts the car without issue but the key fob doesn't lock or unlock the doors or trunk regardless of where the fob is pointed or how close I am to the door handle.
Here are the things I have tried to do thus far in an attempt to solve the issue:
-Both keys are doing the same thing, no locking/unlocking
-New batteries in the key fobs, red light flashes when buttons are pressed
-Confirmed IR is functioning with phone camera
-Synced the key fobs again
-Checked all the central locking fuses, 21,22,32,57
-Also checked the convenience fuses 8,9,33
-The center console lock/unlock button functions as normal
Does the W203 have the All Activity Module (AAM)? Not sure what else could be causing this issue.
Thanks in advance,
Bimmerod
Here are the things I have tried to do thus far in an attempt to solve the issue:
-Both keys are doing the same thing, no locking/unlocking
-New batteries in the key fobs, red light flashes when buttons are pressed
-Confirmed IR is functioning with phone camera
-Synced the key fobs again
-Checked all the central locking fuses, 21,22,32,57
-Also checked the convenience fuses 8,9,33
-The center console lock/unlock button functions as normal
Does the W203 have the All Activity Module (AAM)? Not sure what else could be causing this issue.
Thanks in advance,
Bimmerod
Junior Member
Joined: Dec 2020
Posts: 22
Likes: 7
From: North Central Texas
2006 Mercedes C55 AMG
2006 C350 - Key Fob Lock/Unlock not working
My C55 did the same thing. It was caused by a failed IR receiver behind the outside door handle. On the C55 WIS document # GF80.20-P-0005-01PP showed the location. AR80.30-p-4305 gave instructions on removal of the door handle. You will probably need a long shaft T20 star driver. After removal you will need to dig out (be careful here) the silicone on the "island" end of the IC and solder the connections there. Then recover with silicone or use acrylic conformal coating or build up several layers of fingernail polish. Re installation is a bit fiddly, just be sure to align the interior lock mechanism with the door handle.
Check here for some helpful hints.
https://www.benzworld.org/threads/do.../#post-5582019
Hope this works for your car.
Check here for some helpful hints.
https://www.benzworld.org/threads/do.../#post-5582019
Hope this works for your car.
Thread Starter
Junior Member
Joined: Oct 2021
Posts: 16
Likes: 0
From: California
2006 C350
Apologies for the late response.
I tried disconnecting the battery for 10+ minutes since that was also suggested. After initially hooking it back up it worked a couple times if I was close to the drivers door. After a quick drive around the block it started doing the same thing where it was intermittently working. Even if I held the fob right next to the door handle it wouldn't work. Then a few minutes later it might lock but then not unlock. it's so random and doesn't make any sense.
So I'm not sure if it might be the IR sensor in the handle itself or the antenna amp in the rear headliner area next to the rear window?
I took a look at that thread and will see about taking apart the door handle to check the connections.
Thanks for your time,
Bimmerod
I tried disconnecting the battery for 10+ minutes since that was also suggested. After initially hooking it back up it worked a couple times if I was close to the drivers door. After a quick drive around the block it started doing the same thing where it was intermittently working. Even if I held the fob right next to the door handle it wouldn't work. Then a few minutes later it might lock but then not unlock. it's so random and doesn't make any sense.
So I'm not sure if it might be the IR sensor in the handle itself or the antenna amp in the rear headliner area next to the rear window?
I took a look at that thread and will see about taking apart the door handle to check the connections.
Thanks for your time,
Bimmerod
Junior Member
Joined: Nov 2022
Posts: 20
Likes: 0
2005 s430 matic
Did this ever get answered ?
I have a similar issue with an “05 S430 4Matic .
My question is this . See “Perplexing Key Fob/PSE issue “ .
When pressing the fob did the PSE pump come on ?
The only thing I can think of is that the door actuator blocks air from flowing through to the lock/unlock button when there is an RF or similar malfunction .
Is this possible ? Because having access to the pump and actuator , like I Do now , while trying to figure this out , both fob and dash lock /unlock send the same air to the actuator and I can hear it leaking . I would think of if somehow possible that programming would be done at the PSE itself not to send air into the actuator and force close it and wear it out . Thoughts ???
Thanks !
My question is this . See “Perplexing Key Fob/PSE issue “ .
When pressing the fob did the PSE pump come on ?
The only thing I can think of is that the door actuator blocks air from flowing through to the lock/unlock button when there is an RF or similar malfunction .
Is this possible ? Because having access to the pump and actuator , like I Do now , while trying to figure this out , both fob and dash lock /unlock send the same air to the actuator and I can hear it leaking . I would think of if somehow possible that programming would be done at the PSE itself not to send air into the actuator and force close it and wear it out . Thoughts ???
Thanks !
