R129 1995 SL320 keys

[Shadychris]

I recently bought with what was supposed to be 2 keys\fobs. I failed to check when I purchased and now turns out the second key is nothing to do with my SL..
Even had I checked I would have still likely purchased as all the purchasing guidance I was following was mainly around roof problems, rust areas and wiring looms, which in this case were all fine.
I hadn't read any advice about making sure the car had a spare IR fob\keys....

So I have just the one IR key\fob. I tried RMK but they want a whopping £450inc and require me to visit them in Birmingham, thus adding another £100 or so to the cost...

I'm now starting to panic a bit in that if my IR key fob fails (or I lose the key\fob) and I can't turn off the immobiliser I'm left with a very expensive paperweight.

What if any are my options here??
a) Is it possible to fit a complete s\h set of locks and immobiliser that might have a couple of keys with it? Although I suspect the cost to do that is probably more than RMK quote...
b) Can I get rid of\remove the immobiliser completely and maybe just get a spare blade (valet) key only to lock and start the car?
c) Or should I just sell it on quick in the hope that someone else is willing to take a gamble (or doesn't know the risk) of only having one key..

Or any other ideas?? I really like the car, but this concern is starting to take the edge off my enjoyment....

 

[Jigglyjohnson]

Have you spoke to your local mb dealer for a price on a new key .?
May not be as much as you think and I don't think going down the line of a s/hand lock set would be more beneficial as the immobiliser may be an issue

 

[Shadychris]

Have you spoke to your local mb dealer for a price on a new key .?
May not be as much as you think and I don't think going down the line of a s/hand lock set would be more beneficial as the immobiliser may be an issue

Unfortunately it seems MB stopped supplying these R129 keys\fobs a few years ago

 

[219]

I recently bought with what was supposed to be 2 keys\fobs. I failed to check when I purchased and now turns out the second key is nothing to do with my SL..
Even had I checked I would have still likely purchased as all the purchasing guidance I was following was mainly around roof problems, rust areas and wiring looms, which in this case were all fine.
I hadn't read any advice about making sure the car had a spare IR fob\keys....

So I have just the one IR key\fob. I tried RMK but they want a whopping £450inc and require me to visit them in Birmingham, thus adding another £100 or so to the cost...

I'm now starting to panic a bit in that if my IR key fob fails (or I lose the key\fob) and I can't turn off the immobiliser I'm left with a very expensive paperweight.

What if any are my options here??
a) Is it possible to fit a complete s\h set of locks and immobiliser that might have a couple of keys with it? Although I suspect the cost to do that is probably more than RMK quote...
b) Can I get rid of\remove the immobiliser completely and maybe just get a spare blade (valet) key only to lock and start the car?
c) Or should I just sell it on quick in the hope that someone else is willing to take a gamble (or doesn't know the risk) of only having one key..

Or any other ideas?? I really like the car, but this concern is starting to take the edge off my enjoyment....

I only got one IR key with my car , and also baulked at the cost of a second one . I just bought two standard keys from the dealer at a cost of about £24 each . When you lock/unlock the car by putting the key in the lock and turning it , it arms/disarms the immobiliser .

I’m sure I read that new IR keys for the R129 are no longer available from MB .

Remember to ask for ‘Master Keys’ which lock and unlock everything - these are the ones with the square heads ; the valet key has a rounded off head and will not fit the locks for the boot or interior storage compartments ; the final key in the set is the ‘skeleton’ key , which is the metal blade only ( no plastic head ) and designed for emergencies, to either be kept about your person or hidden in a secret place somewhere under the car ( I never tried whether these open the boot etc , yet they have been in the key sets of numerous MBs I’ve had .

With my W140 , sibling to the R129 , I got a credit card sized emergency key which has RF to lock unlock ( but no IR ) and a skeleton blade which can be slid out to start the car . That wasn’t an option for my prefacelift R129 but yours being a later car it may be . I found that keeping it in my wallet constantly pressed the buttons and ran down the batteries - these days I keep a couple of batteries in the car but can still open it ( W140) by putting the blade in the lock and turning it .

 

[Doodle]

IR keys for the R129 et al have come in and out of production a couple of times over the past few years. Last time I checked they were available on an ongoing basis, I believe MB have managed to arrange a new supplier.

 

[alabbasi]

I heard that they keys are now available. Have them double check.

 

[Shadychris]

Thanks for the suggestions above. When I queried why the £450 price tag with RMK compared to the £180 they quote on their website Matt replied:

The £150 plus vat price is for a version of spare key that is lot more readily available and a lot easier to program.
The version of key you require is not available through other companies and Mercedes on the most part, hence the price.

I guess it wont hurt to try asking a around a few of the SW stealers - nothing ventured nothing gained ...

@Pontoneer - thanks I'll defo invest in a couple of spare standard keys. However my R129 is also pre-facelift and according to the handbook came with 2 x Remote keys. 1 x Master Key. 1 x auxilairy (valet) and one flat (skeleton) All a bit academic as mine only came with the one remote. However also according to my handbook:

"The immobiliser is activated when the car is locked with the remote control. The engine can only be started if the car has been unlocked with the remote control. The immobiliser is not activated by locking the car with the key. If the engine cannot be started, lock the car and then unlock it again with the infrared control."

But - I have tried locking mine with the key to avoid enabling the wretched immobiliser, only to find when I unlock with the key and turn the ignition to pos2 the red and green LEDS in the mirror flash alternatively and the car will not start (immobiliser enabled) until I first take the key out and point the remote at the mirror and lock and then unlock it again.... The only way to avoid the immobiliser kicking in is to never lock the thing at all!
Unlike your description (and my manual) it seems that locking with the key will enable the immobiliser - but unlocking with the key doesn't disable it :-(

This takes me back to the situation of only having the one remote fob that is required to start the car (unless I never lock it). If that fails then what was an other wise fine car with many years life left in it suddenly becomes a parts car... :-(
It really seems to me that the only sure fire answer to my situation is to completely disable the immobiliser - but I'm not sure that is even possible. Seems to be a lot of contradictory advice about these R129's re alarm\immobiliser. I've read that the solution is to be found at the K28 relay - but have no idea where to even find that relay or what to do with it..

 

[219]

Thanks for the suggestions above. When I queried why the £450 price tag with RMK compared to the £180 they quote on their website Matt replied:

The £150 plus vat price is for a version of spare key that is lot more readily available and a lot easier to program.
The version of key you require is not available through other companies and Mercedes on the most part, hence the price.

I guess it wont hurt to try asking a around a few of the SW stealers - nothing ventured nothing gained ...

@Pontoneer - thanks I'll defo invest in a couple of spare standard keys. However my R129 is also pre-facelift and according to the handbook came with 2 x Remote keys. 1 x Master Key. 1 x auxilairy (valet) and one flat (skeleton) All a bit academic as mine only came with the one remote. However also according to my handbook:

"The immobiliser is activated when the car is locked with the remote control. The engine can only be started if the car has been unlocked with the remote control. The immobiliser is not activated by locking the car with the key. If the engine cannot be started, lock the car and then unlock it again with the infrared control."

But - I have tried locking mine with the key to avoid enabling the wretched immobiliser, only to find when I unlock with the key and turn the ignition to pos2 the red and green LEDS in the mirror flash alternatively and the car will not start (immobiliser enabled) until I first take the key out and point the remote at the mirror and lock and then unlock it again.... The only way to avoid the immobiliser kicking in is to never lock the thing at all!
Unlike your description (and my manual) it seems that locking with the key will enable the immobiliser - but unlocking with the key doesn't disable it :-(

This takes me back to the situation of only having the one remote fob that is required to start the car (unless I never lock it). If that fails then what was an other wise fine car with many years life left in it suddenly becomes a parts car... :-(
It really seems to me that the only sure fire answer to my situation is to completely disable the immobiliser - but I'm not sure that is even possible. Seems to be a lot of contradictory advice about these R129's re alarm\immobiliser. I've read that the solution is to be found at the K28 relay - but have no idea where to even find that relay or what to do with it..

Maybe I didn’t have the immobiliser , but I certainly had an alarm , I know because it went off once when I stupidly opened the bonnet while the car was locked , and I can’t remember how/why ... nor did mine have any flashing lights on the mirror - mine was a 93 300SL-24 I think there was more than one revision and I think the 320 replaced the 300-24 ...

 

[MD5]

Thanks for the suggestions above. When I queried why the £450 price tag with RMK compared to the £180 they quote on their website Matt replied:

The £150 plus vat price is for a version of spare key that is lot more readily available and a lot easier to program.
The version of key you require is not available through other companies and Mercedes on the most part, hence the price.

I guess it wont hurt to try asking a around a few of the SW stealers - nothing ventured nothing gained ...

@Pontoneer - thanks I'll defo invest in a couple of spare standard keys. However my R129 is also pre-facelift and according to the handbook came with 2 x Remote keys. 1 x Master Key. 1 x auxilairy (valet) and one flat (skeleton) All a bit academic as mine only came with the one remote. However also according to my handbook:

"The immobiliser is activated when the car is locked with the remote control. The engine can only be started if the car has been unlocked with the remote control. The immobiliser is not activated by locking the car with the key. If the engine cannot be started, lock the car and then unlock it again with the infrared control."

But - I have tried locking mine with the key to avoid enabling the wretched immobiliser, only to find when I unlock with the key and turn the ignition to pos2 the red and green LEDS in the mirror flash alternatively and the car will not start (immobiliser enabled) until I first take the key out and point the remote at the mirror and lock and then unlock it again.... The only way to avoid the immobiliser kicking in is to never lock the thing at all!
Unlike your description (and my manual) it seems that locking with the key will enable the immobiliser - but unlocking with the key doesn't disable it :-(

This takes me back to the situation of only having the one remote fob that is required to start the car (unless I never lock it). If that fails then what was an other wise fine car with many years life left in it suddenly becomes a parts car... :-(
It really seems to me that the only sure fire answer to my situation is to completely disable the immobiliser - but I'm not sure that is even possible. Seems to be a lot of contradictory advice about these R129's re alarm\immobiliser. I've read that the solution is to be found at the K28 relay - but have no idea where to even find that relay or what to do with it..

Does your key have a single, circular button with a flip out blade? It sounds as though you have the MBSS alarm/immobilser fitted, as on my 96 car. As others have said the keys have come and gone and come back into availability at the dealers.

On mine the immobiliser cuts in automatically after about 30 seconds of removing the key from the ignition, whether you lock the car or not. As you have noted you then have to point the remote at the rear view mirror to lock and then unlock if you hadn't locked it in the first place.

If we are talking about the same system, try the main dealer and it's not even a two minute job for them to pair the remote to the car, assuming the locks are original.

 

[Shadychris]

Does your key have a single, circular button with a flip out blade? It sounds as though you have the MBSS alarm/immobilser fitted, as on my 96 car. As others have said the keys have come and gone and come back into availability at the dealers.

On mine the immobiliser cuts in automatically after about 30 seconds of removing the key from the ignition, whether you lock the car or not. As you have noted you then have to point the remote at the rear view mirror to lock and then unlock if you hadn't locked it in the first place.

If we are talking about the same system, try the main dealer and it's not even a two minute job for them to pair the remote to the car, assuming the locks are original.

Thanks Mike for confirming that - Yes I have the single button flip out blade style key. I do appear to have the MBSS alarm/immobiliser fitted. I discovered that a few weeks back when I found the supplementary MBSS leaflet in my service wallet pack. Even that is at odds with reality though, as it suggests that unlocking the car with the blade key only opens the drivers door so you can get to your spare IR fob batteries, and other doors wont open and the alarm will sound. On mine both doors and boot lock will lock and unlock (centrally) when using the key...
You are right though - I've just checked and it is the case that regardless of whether I lock or unlock the door on exit after ~30 seconds of removing key from ignition I hear a faint beep from under the bonnet and the immobiliser has kicked in. Grrrr

So for some peace of mind it seems I have 2 options - either shell out £450 for a new IR key fob from RMK (or possibly from MB if they have stocks again).
Or my preferred option of somehow completely disabling\bypassing the immobiliser system...

I just found a 2017 invoice in my service history for 5 hrs 'carry out diagnostic check on vehicle' and a further 2.5hrs to repair broken circuit board in interior mirror and re-program immobiliser system.... £495 thank you very much... My confidence in this system is rapidly disappearing.

 

[MD5]

My confidence in this system is rapidly disappearing.

I would have hoped that the records in your service history might be an indicator of a new lease of life, and it seems to be working okay at the moment, even if not as described in the manual, but the same way as mine does (and has for 17 years). My first call would be to the main agent tomorrow and hope that they can get you a spare key. I bought mine when they were about £70 each (Vauxhall were charging £90 plus another £15 to programme it at the time!).

I know the MBSS is old tech, but was Thatcham 1 approved back in the day. I've heard conflicting stories as to whether they were factory fitted or optioned to be installed at the dealership, but I don't know how difficult it would be to remove. Hopefully you'll get an experienced old timer on the phone if you phone their parts dept! Keep us posted, and good luck.

 

[219]

That is certainly somewhat different to my car ; I had nothing in my interior mirror , no lights or LEDs of any kind . On my car the sensors were in the door and boot locks , with red and green lights which would flash , either with the IR key button , or with a turn of the key in any lock .

Alas , my CL never worked , although the pump could be heard running , there seemed to be a vacuum leak somewhere.

To me , it makes no sense at all that they make and supply the master/valet/skeleton keys for these cars if they cannot be used to open and drive the car ; and indeed I did drive my car over 100,000 miles over my. seven years ownership just using one of the two master keys I bought - the IR key remained in a kitchen drawer throughout .

 

[E55BOF]

Check with the dealer tomorrow, and good luck.

 

[Doodle]

I know the MBSS is old tech, but was Thatcham 1 approved back in the day. I've heard conflicting stories as to whether they were factory fitted or optioned to be installed at the dealership, but I don't know how difficult it would be to remove. Hopefully you'll get an experienced old timer on the phone if you phone their parts dept! Keep us posted, and good luck.

The 1995 system precedes Thatcham certification, and is technically different. The Thatcham system uses a software lock, which to the best of my knowledge is not possible until you reach the Motronic ECU on the facelift cars.

 

[MD5]

The 1995 system precedes Thatcham certification, and is technically different. The Thatcham system uses a software lock, which to the best of my knowledge is not possible until you reach the Motronic ECU on the facelift cars.

I haven't checked recently, but when I bought my car 17 years ago I searched for insurance purposes and mine was Thatcham cat 1 approved, as shown here.

 

[Doodle]

Being 1996 yours is presumably facelift then?

 

[MD5]

Being 1996 yours is presumably facelift then?

It is and on a P plate.

 

[Shadychris]

Brief update.
Calls to MB Truro and Exeter both confirm IR key fobs currently not available. No indication of when, if ever, they may come available again.
MB Truro can supply spare master key only at a price of £30 +VAT

So its back to 2 options - bite the bullet and get an IR fob from RMK, or bypass the immobiliser completely.
I'm sure the latter must be possible - all an immobiliser does is to create physical breaks in fuel pump and\or ignition system circuits (I don't have starter motor lockout as per the RFID transponder sytem) so it should just be a matter of identifying where those breaks are occurring and permanently bypassing them..

Local Redruth indy not really knowledgeable about R129 immobiliser and suggested to call the SL Shop.
Chap I spoke to at SL Shop seemed to understand the problem - and is going to check with their workshop to see if they are able to bypass the immobiliser system. Waiting on a call back.

 

[Shadychris]

Update of update... MB Exeter just called me back and now say that they can actually order the IR keyfob - but no indication of how long it will take as they are on back order. Cost £182.00 + VAT - plus however much they sting me for programming it to my car. I guess prolly a minimum 1 hour labour charge so add ~£100.
They don't seem to want any deposit from me - just copy of my V5C and driver licence so I think its wise to get my name on the list for one just in case they do ever materialise..

SL Shop also called back - says they can bypass the immobiliser but it's likely to be an 8 hour job and cost £900....

 

[219]

Brief update.
Calls to MB Truro and Exeter both confirm IR key fobs currently not available. No indication of when, if ever, they may come available again.
MB Truro can supply spare master key only at a price of £30 +VAT

So its back to 2 options - bite the bullet and get an IR fob from RMK, or bypass the immobiliser completely.
I'm sure the latter must be possible - all an immobiliser does is to create physical breaks in fuel pump and\or ignition system circuits (I don't have starter motor lockout as per the RFID transponder sytem) so it should just be a matter of identifying where those breaks are occurring and permanently bypassing them..

Local Redruth indy not really knowledgeable about R129 immobiliser and suggested to call the SL Shop.
Chap I spoke to at SL Shop seemed to understand the problem - and is going to check with their workshop to see if they are able to bypass the immobiliser system. Waiting on a call back.

£30+VAT is very reasonable for master key as it is about seven years since I paid £24 .

Have you spoken to Olly at PCS in Horndean (BlackC55 on here) ?

Don’t know if you are aware but they are R129 specialists and have a separate business restoring and selling them . They could possibly do the immobiliser bypass for less ?

Oh , just another thought ... as I understand it ; each key has its own identity ( the electronic part ) and the car is programmed to recognise it . If you got a secondhand key from somebody like Rob Parker ( also a member here ; he’s in Taunton , from memory ) , Mercman ( specialist breaker in Cornwall ) or Carl Burgess ( r129.co.uk ) specialist R129 and W140 breaker , there’s also a guy Simon up in Yorkshire who breaks 129’s but I can’t recall any details .

If you got another key , you could possibly get Olly to code it to your car : that would sort the electronic side but you’d still need that £30 master key to fit your locks . Please check with Olly that this is possible before buying a used key .