An upgrade alarm (also known as a PLIP alarm or OEM upgrade) is a car alarm that will operate from the vehicles factory remote control. The first thing to be aware of is that for an upgrade alarm to comply with the Insurance standards it is assumed the the vehicle already has a factory immobiliser. If your car does not have a factory installed immobiliser and you still like the idea of your alarm working from the original key remote then the best solution would be to have a transponder immobiliser installed with the upgrade alarm.
There are plenty of upgrade alarm options to choose from including the new generation of CAN-BUS alarms. Over the coming weeks the blog shall go into detail about what each product has to offer.
How Upgrade alarms work
Most Upgrade alarms monitor the vehicles central locking wires. For example when the alarm senses the doors locking it will arm, and then disarm when it senses the doors unlock. The trick is to teach the alarm to arm and disarm only when the remote is used. After all it would not be very effective if you could disarm the alarm by simply flicking the cars unlock button on the door, or forcing a screwdriver into the door barrel and turning the lock!
Teaching the alarm operate from a genuine remote command is generally achieved by two methods. The first is known as the inhibit method, the alarm monitors the switches from the doors (or dash) lock/unlock buttons, if it senses the switch move before sensing the door motors unlock it will ignore the command, this way only a command from the remote which causes the door motor to move first will allow the alarm to arm/disarm.
Hazard Flash Method
The second method used is known as enable mode, with this method the alarm monitors the hazard lights which on some vehicles will flash when the remote locks/unlocks it. In other words the alarm needs to see the doors lock/unlock with the hazard lights. This is not possible on all vehicles as not all have this feature. The biggest weakness with this method is that it maybe possible to trick the alarm by turning the hazard lights on and then unlocking the vehicle. There are ways that a good installer can get around this trick and some alarms are far better than others in detecting this.
Some of the better alarms actually learn the timing of the vehicles hazard and locking signals, rather than simply monitoring them. Anyway hopefully this has not been to technical to follow. I’m sure if you can follow this then the reviews found on this page will make sense to you.