Home' Australian Automotive Aftermarket Magazine : Australian Auto Aftermarket e-Zine - April 14 Contents TECHNICAL COLUMN
To make matters worse, my better half was
in the front bedroom, which is no more than
10m from the car, during the time the vehicle
was stolen and not a noise was heard. Next
morning, a check of the neighbours established
that nobody heard or saw anything suspicious
and there was no broken glass.
According to the National Motor Vehicle
Theft Reduction website, the vehicle in
question has a risk rating of 4 1/2 stars (five is
the best). Thirty were stolen in Victoria and
143 nationally in 2013.
With just under 100,000 vehicles of this
model series registered, the actual risk of this
vehicle being stolen is 1.5 per thousand
vehicles registered, which is approximately half
of the overall theft rate of 3.2 per thousand
Approximately 69 percent of all stolen
vehicles are recovered, with the balance
assumed to be profit-motivated thefts
representing vehicles that are stolen for
conversion to profit either as a whole, or as
separate parts, through various illegal methods.
Only time will tell into which category my
vehicle will fall.
Engine immobilisers became a regulatory
requirement on all new cars sold in Australia
from July 2001. A number of studies since
have shown that the theft rate of vehicles fitted
with an immobiliser have reduced by 60 per
cent, although the effectiveness has markedly
reduced in recent years.
In this article we examine current vehicle
security measures, their effectiveness, and new
An engine immobiliser is an electronic
device fitted to the engine, preventing it from
starting without using the correct
key/transponder. When the key is inserted into
the cylinder or transponder and recognised by
the vehicle, a vehicle ID code is transmitted to
the body integrated unit, which compares it to
the code it has been registered with. The body
integrated unit also compares the vehicle ID
code with the engine control module (ECM). If
these ID codes match with each other, the
system allows the engine to be started.
However if the codes do not match, a number
of parts vital to engine start-up are disabled,
such as the ignition, fuel system and starter
motor. This prevents the car from being hot-
wired, should entry be achieved.
Most vehicle manufacturers use magnetic
coupled transponder systems. These do not
require a power source of their own and operate
in a frequency range of 125 kHz. They have a
very limited communication range.
The process of key identification by
manufacturers is also similar. When the key is
inserted into the ignition lock and turned to on
or run positions, an induction coil mounted
around the ignition lock sends out an
electromagnetic field of energy. The windings
in the transponder chip absorb the energy that
powers an electronic chip to emit a signal. The
signal is usually an alphanumeric set of digits
called the identification code. If the code is
recognised by the security module, the vehicle
may be started.
The identification code can be a fixed code
or rolling code. For a fixed code, when the
transponder is energised, it sends a fixed code
to the security module. Later and more
sophisticated technology uses a rolling code.
When the transponder is energised it sends a
code to the security module. The next time the
transponder sends a code it will have rolled to
the next code, which the vehicle knows because
it has an algorithm to calculate the next code in
its memory. More recent rolling code systems
use vehicle identification number (VIN) data as
One of the most important advantages of an
immobiliser system is that it is passive, in that
the owner does not have to remember to
activate it. On the other hand, keys with the
embedded transponder are more expensive and
time consuming to replace if lost and this
usually requires a visit to the dealer.
In 2013 the Australian Capital Territory
introduced an engine immobiliser scheme in
recognition that the majority of stolen vehicles
are older ones not fitted with immobilisation
technology. Owners of these vehicles can apply
to have an immobiliser fitted to their vehicle by
designated approved and licensed installers.
This service is offered to all ACT residents with
a vehicle registered in ACT at no cost via a
$200 subsidy. A similar service was also offered
to Western Australia residents in the late ‘90s
prior to the introduction of mandatory fitment of
immobilisers in 2001.
Most new cars these days are fitted with
smart keys. These smart keys fit into the
ignition are pre-coded to ensure that only those
keys will open cars with which they are paired.
This coding makes it considerably harder to
create copies and they work in a similar way to
immobilisers. The technology has advanced to
the point that smart keys can allow you to
unlock and start the car without pressing any
buttons. Similarly, the car will lock just by
walking away with the key in your pocket.
Some manufacturers have further developed
smart keys to store personal comfort settings.
VEHICLE FROM THEFT
How does a thief steal a 2008 locked vehicle parked in an inner
suburban street on a rainy Tuesday evening when the keys are in the
owner’s pocket? Well, this happened to yours truly just over a week ago.
Readers are invited to send
technical enquiries of a
general nature to:
60 AUTOMOTIVE AFTERMARKET MAGAZINE APRIL 2014
AM APRIL 2014 - FINAL:AM MAGAZINE SHELL 23/4/14 11:19 AM Page 60
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