Mercedes-Benz Forum banner

1 - 20 of 79 Posts

·
Registered
1993 300e 2.8 - M104 -SOLD, Current: W220 S320, 2000
Joined
·
750 Posts
Discussion Starter #1
This is my write-up for those people who have a funky alarm like mine. I have been putting this off for a while now, but decided to tackle it since i had the cluster out for some other work....

The problem: alarm goes-on when i unlock the car from the driver's door.

Solution: Disable the alarm. You can try to fix it, but i understand it will cost a fortune, and too much of a headache for me. Besides, i don't need it !!!

Step 1: Disconnect the car battery so that the alarm does not go-off, or you get hit by an airbag while removing the cluster.

Step 2: Locate the alarm. In my case, it is under the passenger's feet. remove the floor mat and the foam-backed carpet piece. Unbolt the bolt holding the black plate in place. The alarm is the black box on the left with two big plugs going into it (second picture).





Step 3: Unplug those big plugs. On pre 1993 cars, this should be sufficient to disable the car. Not the case though for 1993+ cars as they have an immobilizer feature that is triggered when the alarm is disabled. so my car would not start after unplugging those two plugs.



Step 4: You have to find the relay with the name k38. It is located under the instrument cluster. by jumpering this relay, you will be able to by-pass the immobilizer, and have a fully functional car without the alarm. So proceed to removing the instrument cluster as seen below, that is the nastiest part of the job as that thing is tricky....in the picture, the cluster is removed



Step 5: Locate the k38 relay. it is in the upper left corner of the cluster space. it is shiny silver in color on my car....pull it out by hand- easy!!





Step 6: in order to bypass the immobilizer feature, you need to jumper pins 30 and 87 on the relay, see the picture below. I ran a copper wire between the two pins. Make sure the wire is as flat as possible so that the relay seats properly





Step 7: put the relay back in place. connect the battery without tightening the terminal. try to start the car, if it starts, remove battery and install cluster.

Step 8: tighten battery terminal, and enjoy your car with no annoying alarm !!!!!:thumbsup: Easy job over all. the hardest part was removing the cluster.....

Good Luck
 

·
Registered
1993 300e 2.8 - M104 -SOLD, Current: W220 S320, 2000
Joined
·
750 Posts
Discussion Starter #2
Just wanted to confirm that i used the car extensively today, no alarm and no problem starting...finally i could stop unlocking my car from the trunk :thumbsup:
 

·
Registered
1974 240D; 1982 300D Turbo; 1992 300D 2.5 Turbo; 1999 E320
Joined
·
11 Posts
So, I've had much the same issue with my '92 300D (drivers side door and alarm going off) A++ for timeliness on this topic. As I was heading home from work today my alarm started going off while I was driving (flashing lights, horn, etc). Gives new meaning to drive it like you stole it I suppose. I pulled the carpet and plate up and unplugged what looked somewhat similar to the post on the ’93 (but then a little different too). I’m hoping someone will confirm I did it correctly.

Did this 30 minutes ago, and did a quick function check. Couldn’t find anything that wouldn’t work after I disconnected the two harnesses and no airbag deployment (my fear). I'm hoping I can go down town tomorrow and not draw attention to myself..

Guess I could have removed to gum wrapper, but hopfully this picture will post.
 

Attachments

·
Registered
1993 300e 2.8 - M104 -SOLD, Current: W220 S320, 2000
Joined
·
750 Posts
Discussion Starter #4
Yes, those are the correct plugs....you are lucky you did not have to pull the cluster like me :thumbsup:
 

·
Registered
Buncha W124's
Joined
·
2,086 Posts
If the alarm goes off when you unlock the driver's door, the fault is most likely the electrical switch attached to the lock tumbler assembly. You can buy the switch separately from the lock tumbler assembly.

I agree though, the factory alarm is more of a nuisance than a theft deterrent. A serious car thief won't be slowed down by any alarm, either factory or aftermarket. The best prevention is to not park your car anywhere that it might get stolen!

:thumbsup:
 

·
Registered
w124 Mercedes Benz 230E
Joined
·
4 Posts
Car swings but dont start

I was dumb enough to jumpstart my 1989 w124 230e. Now my ignition lights does not go on when I try to start the car. Nor does the car start. It swigns though. After connecting a line from battery to coil the car started. I was told that it is my immobilizer. Any advice.
 

·
Registered
1993 300e 2.8 - M104 -SOLD, Current: W220 S320, 2000
Joined
·
750 Posts
Discussion Starter #7
I was dumb enough to jumpstart my 1989 w124 230e. Now my ignition lights does not go on when I try to start the car. Nor does the car start. It swigns though. After connecting a line from battery to coil the car started. I was told that it is my immobilizer. Any advice.
Check the fuse on your OVP relay... you might have fried that relay during the jump start...

if that is ok, you could bypass your k38 relay to disable the immobilizer similar to the manner described in this thread...

good luck :thumbsup:
 

·
Registered
w124 Mercedes Benz 230E
Joined
·
4 Posts
Check the fuse on your OVP relay... you might have fried that relay during the jump start...

if that is ok, you could bypass your k38 relay to disable the immobilizer similar to the manner described in this thread...

good luck :thumbsup:
I must have a different model or my car might have been modified before I bought it. Because I cant seem to find any of the items in the pics. Not the alarm unit nor the k38.
 

·
Registered
2000 ML 430, 2014 MLBluetec
Joined
·
306 Posts
These older post are always helpful. Thanks to all who provided information on disabling the alarm system.
 

·
Registered
1989 300TE
Joined
·
3 Posts
Thanks latief my 89 300te has the same problem, which killed the brand new battery that I lust dropped in it made me so mad. Thank you man.
 

·
Registered
Joined
·
3 Posts
HELP

I was driving my car and suddenly the alarm and the immobilizer went on. I went out of the car and locked it, and unlocked it again. Then the alarm stopped and when i opend the door, the alam started again. What should i do?
B.T.W. it`s a MB W 124 300TD 94 model
 

·
Registered
87 w124 AMG, 87 W201, 94 w202, 99 w210
Joined
·
173 Posts
This is my write-up for those people who have a funky alarm like mine. I have been putting this off for a while now, but decided to tackle it since i had the cluster out for some other work....

The problem: alarm goes-on when i unlock the car from the driver's door.

Solution: Disable the alarm. You can try to fix it, but i understand it will cost a fortune, and too much of a headache for me. Besides, i don't need it !!!

Step 1: Disconnect the car battery so that the alarm does not go-off, or you get hit by an airbag while removing the cluster.

Step 2: Locate the alarm. In my case, it is under the passenger's feet. remove the floor mat and the foam-backed carpet piece. Unbolt the bolt holding the black plate in place. The alarm is the black box on the left with two big plugs going into it (second picture).





Step 3: Unplug those big plugs. On pre 1993 cars, this should be sufficient to disable the car. Not the case though for 1993+ cars as they have an immobilizer feature that is triggered when the alarm is disabled. so my car would not start after unplugging those two plugs.



Step 4: You have to find the relay with the name k38. It is located under the instrument cluster. by jumpering this relay, you will be able to by-pass the immobilizer, and have a fully functional car without the alarm. So proceed to removing the instrument cluster as seen below, that is the nastiest part of the job as that thing is tricky....in the picture, the cluster is removed



Step 5: Locate the k38 relay. it is in the upper left corner of the cluster space. it is shiny silver in color on my car....pull it out by hand- easy!!





Step 6: in order to bypass the immobilizer feature, you need to jumper pins 30 and 87 on the relay, see the picture below. I ran a copper wire between the two pins. Make sure the wire is as flat as possible so that the relay seats properly





Step 7: put the relay back in place. connect the battery without tightening the terminal. try to start the car, if it starts, remove battery and install cluster.

Step 8: tighten battery terminal, and enjoy your car with no annoying alarm !!!!!:thumbsup: Easy job over all. the hardest part was removing the cluster.....

Good Luck
i ripped apart my inst cluster and this relay was not avail... also my cover on the floor was a bit different... no idea where this relay may be.. looked all over no wires of that color even ....:surrender:
 

·
Registered
87 w124 AMG, 87 W201, 94 w202, 99 w210
Joined
·
173 Posts
Bystov, yours seems to be an 87. You will not have the really.
so how do i remove this alarm ? im tired and so are my neighbors and its a matter of time till i get my windows smashed or a good spash of 5F5 on my hood. i live in the ghetto and keeping car open all night is not an option
 

·
Registered
'91 C124 300CE, '06 W164 ML500, '00 BMW MCOUPE, '65 COBRA REPL.
Joined
·
547 Posts
read step 3.



Step 3: Unplug those big plugs. On pre 1993 cars, this should be sufficient to disable the car. Not the case though for 1993+ cars as they have an immobilizer feature that is triggered when the alarm is disabled. so my car would not start after unplugging those two plugs.
 

·
Registered
87 w124 AMG, 87 W201, 94 w202, 99 w210
Joined
·
173 Posts
read step 3.



Step 3: Unplug those big plugs. On pre 1993 cars, this should be sufficient to disable the car. Not the case though for 1993+ cars as they have an immobilizer feature that is triggered when the alarm is disabled. so my car would not start after unplugging those two plugs.


going to go try it now! thanks mate
 

·
Registered
'95 S320
Joined
·
7 Posts
Excellent write up of disarming alarm system. I just can't find the K38 relay. I pulled instrument cluster on a '95 S320 looking for K38 relay. My car also doesn't have the speedometer cable either. Can anyone help me find the K38 relay on this car?
 

·
Registered
87 w124 AMG, 87 W201, 94 w202, 99 w210
Joined
·
173 Posts
Excellent write up of disarming alarm system. I just can't find the K38 relay. I pulled instrument cluster on a '95 S320 looking for K38 relay. My car also doesn't have the speedometer cable either. Can anyone help me find the K38 relay on this car?
dont think its the same set up on a w140
 
1 - 20 of 79 Posts
Top