REDTEES

Is there a reason my unlocking range would all of a sudden become poor. I have replaced the batteries a couple of times. Range has never been great however now Im having to get quite close to the car to open.

b4mmy

That happened to me a few years ago, I kind of got used to it to be honest. And then started using the spare key... so it could be the battery... Have you tried the obvious things like cleaning the sensors etc...?

I don't have the problem anymore cos my central locking servo hydraulic thingy needs fixing...

REDTEES

I have no idea as to how to clean the sensors but would certainly like to try. Instructions?

b4mmy

EEEEeeek, now you've got me.

It was just a wild guess. But, making sure there is no polish or grime on the things that receive the signal... on the doors etc...? And the key....

I got this info from the following link, hope it helps:

============
Locks and Windows

Remote locking and window raising comes standard.

Secret trick: trunk unlocking with a double-click of the remote. I've never had the right touch to get it to work however that feature is in the manual.

Single-button remote, much handier than the three-button version that started in 1998.

Remote control is infrared, not radio as newer models and sub-$100,000 cars today. The 1996 model only has an ugly infrared sensor dangling from the rear view mirror, other models including the 1997 have the sensors integrated in each of every three external locks.

============

http://www.kenrockwell.com/sl/

Bigdot

its just the IR that is weak. nothing we can do about it


Mark

MorrisWu

I have met the same problem, but after replacing the IR key batteries, the problem solved. Have you tried the other IR key? I suppose you should have 2 IR keys.

b4mmy

That's what I did to be honest. When the larger grey key started acting up, I switched to the smaller black key... and after a while that went a bit weak. I guess the battery could be the solution...

ChrisB

The 1999 model I have is hit and miss on remote unlocking. It never works from more than say 15 feet away.

My fob only works 5% of the time on the passenger side from any distance. My wife's fob works 50% of the time on that side.

Both fobs worked well on the driver's side untill recently. Now about 10% of the time I have to press the fob several times at very close range on the driver's side. Sometimes it is just too frustrating and I will actually use the key in the door.

Recently, when I first encountered the fob not working at all, I bought 2 new batteries for my fob. It still did not work. But it did in it's finiky way later and continures to work in a finiky way months later.

I wish the range was like my Jeep. It works from 100 ft + away all the time from any angle. Even from inside a building.

Is the Jeep Raidio Frequency technology while the SL is Infrared? What is the advantage of Infrared?

Are R230 remotes different?

Bigdot

yes the jeep and almost all new cars with remote locking/un are radio. while the 129s are IR. i think they did this so you can know when you unlock/lock your car. so for instance you are walking inside and press the button and accidently unlock your $100K ca, and also so you can put the windows up/down when you know about it, not while you put your key in your tight jeans and non purposly roll the windows down.

MArk

Mark

b4mmy

I have accidentally unlocked my Mini Cooper when in a bar, a shop, the office next door, and when using the bathroom at home... and often the car is unlocked when I get to it in the morning.... so I guess IR does have a security advantage.

However it's really frustrating that the IR on the Merc works erratically.

Anyone have any other ideas on getting the IR to work more efficiently?

raymond g-

Since these operate in tandem with receiver/Rx, it would be one or the other
being the weak point. We don't really have option of changing anything on
the receiver (other than cleaning the portal) but we do for the transmit/Tx.
I'm wondering if we can improve by replacing the IR LED with a new one
from, say RatShack or any electronic parts shop?

I'll rummage around my spares and see if I dare experiment and be the
guinea pig.

I used to have a meter which can measure relative strength of IR but can't
find it right now. I do have visual IR reader but that's not as accurate.

Bigdot

i have an extra key, so let me know whats up because i would love to try somthing out on my old key

Mark

slvrstar

Welcome to the world of owning a mercedes. If changing the battery doesn't work, live with it. I did.

b4mmy

Same here. I'm happy to guinea pig my spare as well...

raymond g-

On my 99 and 2000 MY E320s the RF (rx is in interior mirror) is the one which
triggers the locking mechanism, whereas the IR is the one activating the
remote open/close of the windows/roof. For the R129 does this differ?

CLINK <----

follow up: I've not had a chance play Dr Franken-Smartkey, but I did
try an old key FOB alarm trick:

- using the Smartkey, continue moving further back until you reach a point
where it appears out of range.

- touch Smartkey to the underside of your chin and see if this effectively
extends the RF range ...continuing to step back and repeating the chin
trick until you reach this new, effective range

Apparently your body acts as a ground plane for the transmitter. Whereas
direct pointing of the Smartkey yielded a 25-30' range, the 'chin' trick
doubled this.

If this works with your older model, it is quite likely that your key/vehicle
is using RF for un/locking as well.

ah gots tuh axe....does 91 model year have window/roof convenience
opening via FOB?

b4mmy

On my 1991 SL the sensors are inb each door and on the boot. They light up when activated... I'm not sure how long this feature lasted, or whether it was changed for later models. Try this link:

http://auto.consumerguide.com/auto/u...d/2462#changes

blueSL

Digital cameras which provide a preview image are good for checking the IR output from a key. No absolute measurement of course but a useful relative indication from one key to another.

Early 129s had an IR sensor in the driver's door handle, linked to green and red lamps. Incredibly there were normal bulbs and if you had an alarm which blinked the lights, the bulbs soon failed and cost a fortune to replace because you had to replace to driver's door lock. The bulbs failed as well because of the vibration when the door was closed. Not a good piece of design.

Later cars moved the IR sensor to a lump under the rear view mirror. There's 3 IR receivers in there to give an omni-directional view but, especially in bright sunlight, it's incredibly difficult for them to discriminate between the IR signal whose signal is milli-watts at best and the background hash. It's possible that one of the IR receivers is faulty, but you do not want to know the cost of a replacement rear-view mirror. Unbelievable.

The newer SL (note I no longer use the tem new, as it's now 4 years old) uses a remote with both radio and IR - radio for longer distance opening and IR for short distance opening of the roof and to provide backup to the radio which can get swamped in certain areas - airports or next to mobile phone masts, for example.

raymond g-

I wonder if we can shoehorn one of these LEDs into the key?

IR LED from Radio Shack

b4mmy

...sounds like a good idea, and cheap! Who's going first?