1986 W201 Alarm malfunction - Need Help - PeachParts Mercedes-Benz Forum

crhenkel · #1 08-31-2007, 10:40 PM

My 1986 W201 190E 2.3-16v has the factory Alarm and it has started acting strange. I learned the hard way not to lock the doors by pushing down on the lock knob so I fixed the lock linkage and have been locking the doors with the key after the doors are all closed ever since. Recently, the alarm has started going off as soon as I lock the doors. The horn has been disconnected so I didnt realize this was happening until I locked the doors outside at night recently. I can see the headlamps flashing showing that the alarm is sounding. No matter which location I lock with all the doors closed, doors or trunk, the alarm triggers. If I push the lock knob on the passenger door down to the lock position with the door still open and close the door the alarm does not sound. Any ideas? I have a spare alarm module and will try swapping it tomorrow. SO....if I lock the car with the lock knob the alarm seems to not trigger, but if I use the key to lock the car in any lock cylinder, the alarm sounds and the lights flash. ANY ideas why and how to fix?

crhenkel · #2 09-01-2007, 01:02 AM

Follow up -
Car does not have any aftermarket remote locks or alarm installed

Alarm shuts itself off after the set time and does not go off again until after the whole locking the door sequence

If the alarm system is bad can it be bypassed or just removed? What harm does it do to just disconnect the alarm module in the pass floor well?

crhenkel · #3 09-01-2007, 11:54 PM

car alarm still messing up and driving me insane!

jmlynick · #4 09-02-2007, 09:14 AM

I had the same problem with my 92 190E 2.3. Since your alarm is mot working properly anyway you should relace or simply remove the alarm control unit.

The alarm control unit is located on the passeger side UNDER the carpet on the incline where your feet rest. Pull out the carpet - it has a "snap" just in front of the seat. Then there is a plastic cover that has a plastic nut.
Remove the cover and unplug the alarm control unit.

Its a 5 minute job.

I hope this helps
John Mlynick

crhenkel · #5 09-02-2007, 11:30 PM

Thanks for the tip. I know where it is and it is easy to remove, i just didnt know if it would cause any issues to just remove the modul;e and drive it like that. I also have a spare, not tested. maybe it is good, got to check it this week.

jmlynick · #6 09-03-2007, 10:28 AM

I removed mine with no issues
John

crhenkel · #7 09-04-2007, 07:06 PM

YEA! I had two spare alarm modules, today I swapped the one in the car for the spares, both spares work and the problem is fixed. The alarm module in the pass foot well was bod in some way that caused the alarm to trigger when ever locking the car. Fixed and done.

Renntag · #8 05-27-2011, 05:32 PM

(Helping a family member roughly 300 miles away. )

Same problem with a 1992 190E.
Factory alarm system.
Alarm will not stop.
Key fob was used to lock/unlock and this triggered the alarm.
Unable to start engine/ no starter motor engagement.

It seems as though starting function has been disabled.
Battery was disconnected/reconnected in an effort to defeat the system with no success.

I relayed info to dig down to the security module and disconnect it. Waiting for report back.

This is one of those.... "a picture is worth a thousand words" situations. What does the module look like? I can assume it is black with white lettering that might start "201......"
Anyone know the part # or how to describe which one it is? Perhaps: " The second one from the right"... for example?

Thanks in advance.

crhenkel · #9 05-27-2011, 06:05 PM

I think I understood in your explanation that a key fob was used to open or close the doors or unlock the doors or turn off the alarm, regardless, if a key fob was used on the car at all, it would have to be an aftermarket alarm/lock/unlock system that has been installed on the car. The 190e model did not ever come out with a key fob to control locks or the alarm. The important thing to find out now will be how the aftermarket alarm was installed. The system has to be installed to operate the locks via the air pump that locks and unlocks so that the mechanism that does the unlocking and disarming operated properly. If the vac system is activated to unlock the alarm system disarms properly. This is the best way to insure that the deoors dont open prior to the oem alarm being disarmed. A quick and easy way to solve this might be to disconnect the OEM alarm module located in the floor board of the front passenger side. Disconnectiing it should still leave the aftermarket alarm or unlock system in tact. There is a chance that your 190E may not have ever even had an OEM alarm, not all did. IF you dont find the alarm module in the floor board, you likely dont have an OEM alarm and your fault is in the aftermarket unit. Also as a note, I am not sure that the OEM alarm had an ignition disable function. Not sure, didnt think that it did. Second, the arm/disarm trigger for the OEM alarm system is in the door lock mechanisim inside the door lock of the drivers side front door. It is activated and disarmed as the lock is operated by the vacuum diaphram of the central locking system. The locking system needs to be working correctly for the alarm to work properly.

crhenkel · #10 05-27-2011, 06:16 PM

The oem alarm module that is under the carpet of the passenger front side floorboard is black, roughly rectangular and has a label on it that typically says
"Mercedes Benz 126 820 08 26 BAW 845 Z 0000 Gepruft: (date manufactured)" It also might have a second sticker on it that shows that it was manufactured by BECKER.

crhenkel · #11 05-27-2011, 07:10 PM

Here is a photo of the alarm module. It has a 126 part number but the appearance is the same.