Immobilizer

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SL 320 1995 auto
Hi, I have a '95 sl320 auto, owned it for the last 15 years, only comes out a few times a year ( summer driving). Stored in garage, battery on trickle charger. When I Garaged for the winter, I noticed the red flashing door handle light was not working (interior rear view mirror was). When I came to start it a week ago, no luck. Green light flashes on door and interior, but when I try to start car both red and green flash, engine turns over with ease but doesn't start, indicating imoboliser fault. Carried out camera test on key fob and all seems well there. So, car battery ok, key fob battery ok, engine ok, just one red light on door handle not working, could this possibly be the cause of my imoboliser problem??. Any one got any thoughts.

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grahamcol

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2001 SLK230, 2007 CLK220 CDI
I don't think the absence of the door light will make any difference. Have you tried to sync the key to the alarm/immobiliser? Procedure is in the manual.
 

PINBALL

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Is it a SCORPION alarm / immo ?

If so then its a dealer fitted system & to cut a long story shorter, it can be fully immobilised by turning chrome round barrel lock a quarter turn if you have an additional key that you've always wondered = 'whats that odd looking key for'

Factory fitted alarms were largely installed in 95.

This barrel lock was fitted INSIDE the glove box on my old 124 Eclass & once disabled only used key to lock n unlock, after scorpion remote failed once and kept me locked out for an hour in pouring rain. late at night on the Amalfi coast in Italy.

So look for an odd looking lock if not inside glovebox as sme were fitted elsewhere dependant on dealer that fitted it.

I never had a key for mine, so once found I stripped out clove inside (not too difficult) and wired lock around the opposite way as if it were unlocked - using a multimeter to check continuity across 4 cables that were connected to lock.

It only unlocked properly mostly by accident after my keeping finger on unlock button for a good 20 seconds, and after that threw the remote pad into the back spare wheel compartment - so you could try that.
 
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SL 320 1995 auto
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I don't think the absence of the door light will make any difference. Have you tried to sync the key to the alarm/immobiliser? Procedure is in the manual.
Thanks, I go look for the manual, haven't seen it for years, I'll keep you posted.

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SL 320 1995 auto
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Is it a SCORPION alarm / immo ?

If so then its a dealer fitted system & to cut a long story shorter, it can be fully immobilised by turning chrome round barrel lock a quarter turn if you have an additional key that you've always wondered = 'whats that odd looking key for'

Factory fitted alarms were largely installed in 95.

This barrel lock was fitted INSIDE the glove box on my old 124 Eclass & once disabled only used key to lock n unlock, after scorpion remote failed once and kept me locked out for an hour in pouring rain. late at night on the Amalfi coast in Italy.

So look for an odd looking lock if not inside glovebox as sme were fitted elsewhere dependant on dealer that fitted it.

I never had a key for mine, so once found I stripped out clove inside (not too difficult) and wired lock around the opposite way as if it were unlocked - using a multimeter to check continuity across 4 cables that were connected to lock.

It only unlocked properly mostly by accident after my keeping finger on unlock button for a good 20 seconds, and after that threw the remote pad into the back spare wheel compartment - so you could try that.
Thanks, I'll look into that, just got to get car out of garage first, but not till this snow goes. I'll keep you posted.

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PINBALL

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If it is a Scorpion alarm, it may not be listed in cars handbook as it was an aftermarket system that MB approved to its dealers.

One easy way to see is if you have 2 stickers on each rear door quarter light windows saying Mercedes Benz Approved Alarm fitted (black print on silver background) which means alarm fitted in factory and should be in handbook.

If not, then its more than likely to have a Scorpion approved remote locking and Immobiliser unit fitted by dealer usually from new.
 
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I don't think the absence of the door light will make any difference. Have you tried to sync the key to the alarm/immobiliser? Procedure is in the manual.
Hi, yes tried syncing, no luck. Done the remote/camera trick, all good. Car battery good, turns engine nicely ( kept on trickle charger). Just mirror red/green flashing madly. Guess I'll have to wait another week for weather to improve so I can push it outside. Any other " tricks" I can try,?

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PINBALL

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How you gonna push it outside if the immo is on?

surely the doors are locked - and if not should be, plus alarm would sound if the bonnet is undone to trickle charge the battery?
 

LostKiwi

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How you gonna push it outside if the immo is on?

surely the doors are locked - and if not should be, plus alarm would sound if the bonnet is undone to trickle charge the battery?
No he can get in but can't start it. Also the battery in a 129 is in the boot, right side under the fuel filler.

OP - sorry but not familiar with the Scorpion system (mine fortunately doesn't have it) but I would be tempted to find it and remove it and rejoin the wires where it connects in.

I've checked all the documents I have (both mine and Malcolms) but have no details I can find of the immobiliser.
 
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No he can get in but can't start it. Also the battery in a 129 is in the boot, right side under the fuel filler.

OP - sorry but not familiar with the Scorpion system (mine fortunately doesn't have it) but I would be tempted to find it and remove it and rejoin the wires where it connects in.

I've checked all the documents I have (both mine and Malcolms) but have no details I can find of the immobiliser.
Hi, I seem to have a similar situation. I can open doors with remote, turn engine over, but it won't"catch", just interior mirror red and green lights flashing. Can select neutral from park. Done camera trick on remote, all seems good there. Car battery good as kept on trickle charger. Mine also as battery in boot and is also garaged, with, unfortunately the book nestles under a worktop, so no access until car is outside, just waiting for weather to improve, cos once out it will have to stay out until problem sorted. Any help/advice appreciated. Also done the key re-synce. Nothing much works at moment. I do have one red light indicated on driver's door not working, wondered if that could be causing the problem. Thanks

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LostKiwi

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I do have one red light indicated on driver's door not working, wondered if that could be causing the problem.
I doubt it.
The door is only a receiver of IR and notifier back. Its a purely passive device.
 
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I doubt it.
The door is only a receiver of IR and notifier back. Its a purely passive device.
Thanks, that's a bit of a relief.

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LostKiwi

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If you have a factory immobiliser then the immobiliser is not the problem. The factory one works by disabling the K38 relay preventing the engine from cranking.
If you have a Scorpion get rid of it. They were dealer fitted and are known to cause issues and have no backup any longer. Are you sure you have a working fuel pump?
 
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If you have a factory immobiliser then the immobiliser is not the problem. The factory one works by disabling the K38 relay preventing the engine from cranking.
If you have a Scorpion get rid of it. They were dealer fitted and are known to cause issues and have no backup any longer. Are you sure you have a working fuel pump?
Yes, pretty sure everything else is working. Bought car 2nd hand in 2003. Have no idea what system is fitted, but on your information it sounds like a scorpion. Only done about 6000 miles since then. Garaged most of time. So if it is a scorpion, when (if) I find it and remove will central locking still work with the key remote? Many thanks.

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LostKiwi

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'93 500SL-32, '01 W210 Estate E240 (RIP), 02 R230 SL500, 04 Smart Roadster Coupe, 11 R350CDi
Yes, pretty sure everything else is working. Bought car 2nd hand in 2003. Have no idea what system is fitted, but on your information it sounds like a scorpion. Only done about 6000 miles since then. Garaged most of time. So if it is a scorpion, when (if) I find it and remove will central locking still work with the key remote? Many thanks.

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Yes it will.
The central locking is controlled by the car and the immobiliser is just an add on.
 

Richard Moakes

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If you have a factory immobiliser then the immobiliser is not the problem. The factory one works by disabling the K38 relay preventing the engine from cranking.
If you have a Scorpion get rid of it. They were dealer fitted and are known to cause issues and have no backup any longer. Are you sure you have a working fuel pump?

Do you know where the Scorpion interrupts the R129 fuel pump circuit on a dealer fitted system?




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PINBALL

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If its a Scorpion then central locking will be on a separate pad to key, or at least thats what i had on the E280 1994.

Here's a pic of what lock in glovebox looked like, and i did not have a key to disarm it.
upload_2018-3-11_12-50-49.jpeg

All i did was cut all 4 wires and taped up ends so that none were connected, but left enough wires on back of lock barrel (2-3") so i knew where they went to connect up again if that idea failed to end the immobilizer from working, but found that unnecessary.

This a similar fob that i had.

upload_2018-3-11_13-0-31.jpeg

Just disconnecting those 4 wires did the trick and i just used key in locks after dousing them in proper lock graphite powder spray every 6 month's or so into ignition as well as both doors and tailgate.

USED THIS STUFF FOR 6 years after scorpion was disconnected and thrown into back of car should it ever be neccesary to reconnect for any obscure reason, but i just wanted to be safer and know i can unlock it when i want it unlocked without fail.

With key in drivers door lock swung around to unlock & if kept there all windows drop and vica versa - same as remote can do.

upload_2018-3-11_13-6-30.jpeg
Hope it helps.
 
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