Trader2010

My key remote started giving problems about a month ago*, the first time it was hit and miss at unlocking the doors. I checked my spare key same problem, next day all was well. Then last night I could not get the doors to lock, had to do it manually. This morning I drive to a friend’s house, get out, and lock the doors, A Okay. When I go to leave the remote would not unlock, I used the key to get in, alarm goes off, put key in ignition switch alarm stops. On way to store to but new batteries for remote, just in case that’s it, I decide to listen to the radio, FM, (stick with me here). Arrive at store, and remote will not lock doors. I come out of store remote unlocks door, start car, radio reception is awful, check other stations the same. Arrive home when I turn the engine off radio reception returns to normal, start car, reception bad, and multifunction display reports BAS and ESP error. Several more restarts of car, errors are not repeated, but radio reception still poor and remote will not work. Let are set for 10 minutes, start car radio fine, remote works. Some kind of RF interference issue? Rest of day radio continues to be okay, remote still flaky. Finally this evening remote will not work, but if I point key at IR sensor on door handle it then works.

* Problem started shortly after I had cam solenoid replaced along with ECU and wire harness, and O2 sensor all damaged by cam solenoid oil leak.

Any thoughts?


Trader

Glyn M Ruck

Yes. You are having RF antenna problems. Hope you have not had a tint recently. Remember Key batteries only power RF & IR. The key is inductively energised by the EIS when in the ignition slot.

Causes

Metallic tint ruins reception
Tint people cutting wires to rear screen antenna
Antenna sticky pad at top dead centre of the rear window not staying stuck - start here if you have not had a recent tint!
Antenna amp in the LHS rear C pillar blown
Antenna amp poor earth/ground
Antenna amp blown by water from tinting process



Lots of threads on this problem

Glyn M Ruck

See my comments on Kalim's thread

Glyn M Ruck

Here transferred to keep thread complete

OK - In your case it's definitely not the tint if everything worked fine after they were done. Then you do not have metallic tints.

Then as I said in the other thread.

Check connection at sticky pad TDC rear window under the headliner. (no need to remove liner)
Check earth/ground on antenna amp
Check that antenna amp has not blown - They do quite often & have been redesigned many times.

You say your radio reception is awful - It uses the same RF antenna embedded in the rear glass. You have an antenna circuit problem. Do checks above.

Good luck!

Trader2010

Thanks,

Last night only IR worked, even though radio was fine, today all is as it should be. I have yet to see any pattern or cause as to why things change, time may tell, or a trip to the shop.

Thanks again for the help.

maverik259

i have the same issues time to time...soemtimes it'll take me about 90 seconds of pressing the unlock/lock button to open/close my car...its retarted.

Glyn M Ruck

Give the sticky pad a shove at top dead center of rear screen. If it's intermittent that or ground are usually the likely culprits. Years of sun effect how well it makes connection. If this does not work pop off the C pillar cover. You will see the amp sitting there. Check all connections.

thetreborman

Hi - thought it'd make sense continuing on this thread as it already covers some of the issues I'm having

I'm driving a 2001 C-class Coupe C230K and I have been having a problem with the key remote. Quite simply, it was intermittant probably once then hasn't worked since - meaning I have to manually open the car each time which is quite annoying.

The central locking button inside works fine - how I lock it now with key
No problems with radio and all doors open fine when i open car door after driving a while

I have tried testing for a loose connection on the sensor but no good - also tried with both sets of keys and checked batteries.

Could the problem perhaps be a fuse?
If so any idea which fuse I need to replace?

P.S Not had any windows tinted

Any help would really help - Thanks

Trader2010

Back in October 2010 I pulled the upper trim from the inside of the hatch and found the antenna amp, I pushed and fiddled with it and it didn't seem to change anything. It was still hit and miss. Then in June 2011 it started working just fine and to this day is working. I hope I have not jinxed myself. Go figure.

Good luck

thetreborman

I've only tried securing the connection by the rear view mirror in the centre of the front windscreen, I assumed that was where this sensor was.

I'll try having a look inside the hatch trim,thanks for getting back to me

I've read on another thread:
Only thing is I'm a bit apprehensive to start pulling out all these fuses. Is it safe to do this? I just don't want to cause any other problems.

What would you advise?

Glyn M Ruck

You need to do all the checks on the hatch at the back. This has nothing to do with the front windscreen.

thetreborman

Still no luck..

• new batteries in both sets of keys
• checked the sensors on the rear windscreen
• replaced all relevant fuses one by one with new fuses but still nothing

Thought I might of cracked it now.


Anyone got anymore advice that might be helpful?

D-Benzo

Hey everybody how's it going, My recent situation is with a Mercedes c230 Kommposser. Basically what has happened is I left the key to it in the ignition and turned to the battery position (one before actual start) for about an hour with the high beams on and the music on low. When I realized I had for forgotten the car on I ran back to find the car was dead (obviously). I connected it to a jumper also directly connected to a power outlet and tried to start it and nothin. All electronic pieces in the car seemed to be very dimmed. I let it charge for about 30 minutes got back inside and inserted the key once more. Still no start. However the doors lock/ unlock still work off the remote, as well as the panic button. Music works fine, lights, windows, etc but the only thing that is the problem is that once you come to start it (tap to the right) it won't start, as if there is no connection. There is a sound in the engine that sounds like its coming from the front right if your looking from inside the car. Does anybody have any advice as to how to fix the problem so I can start my car again please. Its going to cost me around 6-700$ at the Mercedes Benz Dealership. All your help is greatly appreciated.

P.s. this is my first time posting one of these if this is the wrong spot or I should fix anything, please let me know. I greatly appreciate your guys' time.

Thank you and have a great day!

LILBENZ230

Sounds like you've just really killed the battery. Just because a battery can operate accessories does not mean it has what it takes to start the engine.

Glyn M Ruck

Check fuse 52 in the front SAM. Sounds like it's blown. Upgrade from 15A to 20A. See bulletin in the Wiki.

Elbalt

I’m having the same exact problems you just described. My car is a 2007 s550. I just replaced my cam adjuster magnets and oxygen sensor and then my fob started acting the way you stated in your post. How did you solve the problem?