92 500 SL Central Locking Remote has a mind of it's own

[Mike Miller]

Before you ask, yes I put in a new battery.

The thing works fine when it wants to. However, sometimes it refuses to unlock with the remote or other times lock. The remote works on the trunk when it feels like working and sometimes not at all. It's not a huge problem, because I can always use the key. It is just annoying.

Anybody else have a similar problem and an economic fix. Please don't tell me it's another $2500 wiz-bang electronic module!!!

[Mike Miller]

Come on guys, somebody must know something.

[Mike Miller]

Well, so much for interest in this one. Guess I'll move on.

[LeaUK]

Mike....whooooooooooah

I hear you, I just fell asleep on my nice new sofas this evening and forgot to log on. Right, don't panic I can offer a probable solution - but of course if you had used the 'search' facility you would have a probable answer I have been here and done it - so to speak....

Here's a couple of questions you need to consider:

1. does the remote operate more satisfactorily at night?

2. during the day, if you surround the remote receiver with cupped hands such that the sunlight doesn't hit the IR receiver, will the remote operate now?

3. does the red or green light flash more times than it should and with irregular counts?

In summary (as both these threads conclude) if your remote operates better at night or/and with you blocking the sunlight entering the IR receiver you need to change the RED/GREEN IR receiver and key barrel (sold as one part). I replaced both of mine to a cost of around 300GBP so they're not cheap but was one of my best purchases two years ago! Here's some pccies of the barrel assembly revisiting infrared remote system malfunction

It's a long thread but worth reading IMHO..

Outside door lock lights stay on

then here for the answer to my problems:
revisiting infrared remote system malfunction

Hope this helps
Lea

[Mike Miller]

Thanks, Lea. I will check it out. I believe it works better out of direct sunlight.

I am still getting used to the forum and am not much good at searching yet. I appreciate the time you took to put your response together. I have an apron I wear while on the BBQ. It says: NO DUMB**** QUESTIONS!". Maybe I should hang it next to the computer.

[LeaUK]

LOL

Hey no problem. Anyway I hate those people who shout 'use the search' so after re-reading my post I'm sorry to sound a little hypocritical myself - apologies.

If I can help I will, so please let me know how you get on. Remember check the IR in pitch black against daylight. On my car this test was quite easy as there was significant differences in response ie at night the remote worked, in the day it failed 50% of the time from the drivers door, but was fine on the boot. However if yours is less intermittent maybe you'll need to wait a few months or so until it really begins to suffer.


Lea

[Mike Miller]

You have now got me on the right track. Mine works 75% of the time on the drivers door, 50% passenger, 10% boot. A little different than yours, but the same problems. I need to do the dark vs light test to verify. I'll let you know. Thanks again.

[LeaUK]

Dark vs light is the key to see if you need to replace your receivers - although seems strange that ALL yours are failing!

When the CL does respond, does the green lamp flash a random number of times? If so, this I believe is a clue and the module is telling you that it failed to receive the correct IR pattern.

Another quick check you can do is point the IR transmitter at a video camera. If the camera is sensitive to IR (and most modern ones are) you'll see the digital pattern.


Lea

[Mike Miller]

Maybe it is my hand held remote that is all scratched up and not putting out a strong enough signal in daylight???