New CL65, new key fob headache (remote lock AND keyless go sudden failure)
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Member
Joined: May 2020
Posts: 247
Likes: 58
From: Fort Worth
2005 CL55 AMG || 2005 CL65 AMG || 1989 560SEC
New CL65, new key fob headache (remote lock AND keyless go sudden failure)
SO, I just picked up an 05 CL65!
On the downside, it has several irritating problems stemming from neglect.
I'm getting many of them resolved, but one that is driving me up a wall is the two key fobs. Both are Keyless go enabled, and both worked 80+ % of the time when I first bought the car, and for MOST of the 1000+ mile drive back home (remote lock, unlock, keyless go unlock + start).
Both fobs always had poor reception range (15-20 foot at the absolute max), but unlocking became more and more intermittent, as has the button start function. At this point, the car states "key not recognized" for both fobs, and remote lock/unlocking is inoperable-- I have to lock/unlock with the IR beam.
So, my question to you all is-- What do you think the cause is? Since it's both fobs it isn't fob batteries (changed just in case), since the unlock reception was always poor (compared to my CL55), I am assuming it is the FM antenna above the rear glass (the FM radio quality is notably worse than my 05 cl55), or some other failing component I am unaware of.
For additional info- the previous owner left the car OUTSIDE and I found the trunk full of water- killed the radio of course (fixed). Is there anything y'all can think of that may be bothered by trunk moisture? I know the Keyless Go module is present in the trunk, but since it's ALL keyfob functionality (except IR control) that's died I doubt it's that. I checked fuses that seemed relevant, with none blown.
I'm just not sure what could take out both keyless go and RF fob lock/unlock capacity simultaneously-- better not be the EIS, lol. I've been digging around the w215 and 220 forums for a hot minute.
Thanks!
On the downside, it has several irritating problems stemming from neglect.
I'm getting many of them resolved, but one that is driving me up a wall is the two key fobs. Both are Keyless go enabled, and both worked 80+ % of the time when I first bought the car, and for MOST of the 1000+ mile drive back home (remote lock, unlock, keyless go unlock + start).
Both fobs always had poor reception range (15-20 foot at the absolute max), but unlocking became more and more intermittent, as has the button start function. At this point, the car states "key not recognized" for both fobs, and remote lock/unlocking is inoperable-- I have to lock/unlock with the IR beam.
So, my question to you all is-- What do you think the cause is? Since it's both fobs it isn't fob batteries (changed just in case), since the unlock reception was always poor (compared to my CL55), I am assuming it is the FM antenna above the rear glass (the FM radio quality is notably worse than my 05 cl55), or some other failing component I am unaware of.
For additional info- the previous owner left the car OUTSIDE and I found the trunk full of water- killed the radio of course (fixed). Is there anything y'all can think of that may be bothered by trunk moisture? I know the Keyless Go module is present in the trunk, but since it's ALL keyfob functionality (except IR control) that's died I doubt it's that. I checked fuses that seemed relevant, with none blown.
I'm just not sure what could take out both keyless go and RF fob lock/unlock capacity simultaneously-- better not be the EIS, lol. I've been digging around the w215 and 220 forums for a hot minute.
Thanks!
Thread Starter
Member
Joined: May 2020
Posts: 247
Likes: 58
From: Fort Worth
2005 CL55 AMG || 2005 CL65 AMG || 1989 560SEC
Interesting discoveries. Cleaning the rear windshield contacts by rubbing a thick piece of paper sprayed with windex between them and the radio module pads yielded very occasional operability of the key fob. A couple days later, keyless go door opening began working about 1 in 3 times.
As I've read, Keyless Go also relies on the FM antenna to function, as the car's KG door/trunk coil will prompt the remote to send an unlock signal to the car when you use keyless go... basically the car pushes the unlock button on your key for you when you touch your door handle. This pretty much cinches it for me, so I've ordered a replacement window radio receiver.
No success with KG push botton start, and the car will rarely accept two commands in short succession. (EG: KG unlock, then lock. Or, Key lock, KG unlock. Or, two lock commands twice in a row)
After poking around in the radio, the receiver has a very hard time with stations in the 80/low 90 FM station range. It'll go completely silent sometimes, or catch random other stations with no prompting or station change. Also, the radio/stereo quality is considerably worse than my cl55 amg.
This car has a some amount of chalky/rusty corrosion, so I figure condensate toasted the window unit.
/shrug
As I've read, Keyless Go also relies on the FM antenna to function, as the car's KG door/trunk coil will prompt the remote to send an unlock signal to the car when you use keyless go... basically the car pushes the unlock button on your key for you when you touch your door handle. This pretty much cinches it for me, so I've ordered a replacement window radio receiver.
No success with KG push botton start, and the car will rarely accept two commands in short succession. (EG: KG unlock, then lock. Or, Key lock, KG unlock. Or, two lock commands twice in a row)
After poking around in the radio, the receiver has a very hard time with stations in the 80/low 90 FM station range. It'll go completely silent sometimes, or catch random other stations with no prompting or station change. Also, the radio/stereo quality is considerably worse than my cl55 amg.
This car has a some amount of chalky/rusty corrosion, so I figure condensate toasted the window unit.
/shrug
Last edited by JustTXn; Oct 17, 2024 at 09:34 PM.
Thread Starter
Member
Joined: May 2020
Posts: 247
Likes: 58
From: Fort Worth
2005 CL55 AMG || 2005 CL65 AMG || 1989 560SEC
Replaced the antenna, and I'd say about 90% of functionality is restored (push to start is still hit or miss but everything else almost always works). I'll give it a couple days and see if things improve.
Thread Starter
Member
Joined: May 2020
Posts: 247
Likes: 58
From: Fort Worth
2005 CL55 AMG || 2005 CL65 AMG || 1989 560SEC
Final update:
The fobs work reliably now 95+%, although only at close range (under 15 feet from the car). Not sure what's causing the range issue, but I also don't care. You can pull down the rear of the headliner to remove the antenna, which will likely pull a couple retaining clips etc loose from the glue holding them to the back of the headliner. You can resolve this after you're done by lining everything up as it was (sans the parts adhering to each other), then put some super glue on the three attchment points and push them into place for a minute by holding the headliner up... easy peasy.
The fobs work reliably now 95+%, although only at close range (under 15 feet from the car). Not sure what's causing the range issue, but I also don't care. You can pull down the rear of the headliner to remove the antenna, which will likely pull a couple retaining clips etc loose from the glue holding them to the back of the headliner. You can resolve this after you're done by lining everything up as it was (sans the parts adhering to each other), then put some super glue on the three attchment points and push them into place for a minute by holding the headliner up... easy peasy.
Thread Starter
Member
Joined: May 2020
Posts: 247
Likes: 58
From: Fort Worth
2005 CL55 AMG || 2005 CL65 AMG || 1989 560SEC
I probably will in about 6 months, PO said the battery is "new" (not sure what he considers new). Currently sorting more neglected critical systems before I circle back to this...
Agreed on water causing drama... Will be grabbing replacment parts and replacing obviously corroded components. Audio gateway has been replaced, hydraulic lid opener will probably need replacement.
Just specced/ordered an in-place soft line replacement for the RF strut ABC line (this line has failed on both my w215s), and working through accumulators/pulsation dampeners, then engine mounts.
Agreed on water causing drama... Will be grabbing replacment parts and replacing obviously corroded components. Audio gateway has been replaced, hydraulic lid opener will probably need replacement.
Just specced/ordered an in-place soft line replacement for the RF strut ABC line (this line has failed on both my w215s), and working through accumulators/pulsation dampeners, then engine mounts.
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Joined: Feb 2018
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CL500, W212 e350 mega-spec
Some models of Mercedes have a boosted antenna which requires electrical power to function. On my e-class the fuse for the antenna kept blowing which stopped the key fobs working most of the time and the FM radio couldn't hold a signal either. I found the fuse for the powered antenna in the boot / trunk. Replaced it and it blew again immediately. The cause was something else on the same circuit being faulty. In my case the other things running from the same fuse were identified and of those 3 or 4 different components the faulty one was the siren for the burglar alarm. I disconnected the siren and replaced the fuse and it worked and did not blow. I was able to use the car without the siren for a few weeks while I sourced a replacement. Apparently the siren is a component which goes faulty regularly. The replacement came from a Chrysler Crossfire but is the same PN as the one fitted to Mercedes. During the summer I had started having a problem with the siren going off randomly for no obvious reason.. so this was the signal that the siren was failing.
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Thread Starter
Member
Joined: May 2020
Posts: 247
Likes: 58
From: Fort Worth
2005 CL55 AMG || 2005 CL65 AMG || 1989 560SEC
Some models of Mercedes have a boosted antenna which requires electrical power to function. On my e-class the fuse for the antenna kept blowing which stopped the key fobs working most of the time and the FM radio couldn't hold a signal either. I found the fuse for the powered antenna in the boot / trunk. Replaced it and it blew again immediately. The cause was something else on the same circuit being faulty. In my case the other things running from the same fuse were identified and of those 3 or 4 different components the faulty one was the siren for the burglar alarm. I disconnected the siren and replaced the fuse and it worked and did not blow. I was able to use the car without the siren for a few weeks while I sourced a replacement. Apparently the siren is a component which goes faulty regularly. The replacement came from a Chrysler Crossfire but is the same PN as the one fitted to Mercedes. During the summer I had started having a problem with the siren going off randomly for no obvious reason.. so this was the signal that the siren was failing.
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