W124 E320 Convertible immobiliser problem

[Husaberg]

I Have a '95 E320 convertible that is dry stored on a trickle charger. I drove it out of the garage last week, dropped the roof and stopped the engine. When I tried to restart, the motor turned over but did not fire. This is normal when the immobiliser activates. However, when I did lock/unlock, the problem remains.

I also notice that the red warning light on the dash for the rear headrests is on and will not go out regardless of the headrests being up or down.

I also notice that after unlocking, if the car is left untouched, the alarm normally activates after 1 minute, which is shown by the hazard lights flashing once. This is not happening. I get a green light on the drivers door when I unlock, but don't get a red after locking. These symptoms occur with the transmission in N or P. Any ideas please? The MB siren on nthe N/S wing does not sound, regardless of the key position at the rear of the unit. Thanks, Steve.

 

[Dec]

The key hole on the siren would be to turn the whole alarm system off, depending on which position the key is turned, the alarm is either on or off.

If there is more than 2 wires going into the alarm siren then its likely that there are back up batteries inside the siren and these batteries have now expired… the siren may be a significant part of the alarm system or it might just be a siren.

Intentionally set off the alarm to see if the siren is working.

Dec

 

[Husaberg]

Alarm update

Dec,

Thanks for responding. The sounder box has 4 wires going in and a battery pack inside. It is an MB part (Q3 50 06364). I cannot set the alarm off as it does not seem to be arming (or disarming). The car locks and unlocks on the keyfob or with the key in the door, but does not flash the lights when doing so, or auto arm after 30-60 seconds if left after unlocking. I am assuming that it is not disarming properly therefore not switching the immobiliser off. I have tried disconnecting the main battery. Any other ideas welcome.

 

[grober]

first thing to ascertain is whether you have an aftermarket [ dealer fit] alarm or a factory fitted one. I fits factory fit it may be the immobiliser unit found under the large flat plate in the front of the passenger footwell. Read this THREAD through to the end and have a look at the links.

http://www.mbclub.co.uk/forums/engine/151466-w124-e320-wont-start-immobilser-ecu-wiring-loom-3.html

 

[Dec]

I think that’s a Scorpion alarm, get on to these guys below with that part number, the may be able to advise and supply a user manual if it is one of their alarms.
SCORPION

Dec