Cobra Electronics 7928 Automobile Alarm User Manual

Car Alarm
Thatcham M.I.R.R.C. Evaluation No:
Your Cobra Dealer will be pleased to clarify
any queries you may have with the system
or its operation.
Even when using your Cobra 7928/26/HF
Alarm System we would suggest the
following additional precautions:l Avoid leaving valuable belongings in
the car particularly if they are on view.
l Never leave Registration or Insurance
Documents in the car.
l Never leave spare keys in the car.
l Always try to park in a well lit and safe
The Cobra 7928/26/HF Alarm Immobiliser
is a Category 1 MIRRC Thatcham listed
security system. If the installation of this
product is modified or altered from the
standard specifications, or non compliant
accessories are fitted, the insurance
approval will be invalidated.
User Instructions
Congratulations on purchasing a Cobra
7928/26/HF Alarm System. It has been
designed and manufactured to the highest
standards utilising the latest S.M.D.
technology for total reliability.
PIN Code
Each Cobra 7928/26/HF Alarm System has
a unique PIN code which can be used for
Emergency Disarm and is required,
together with one of the emergency
override touch keys, for programming
replacement or additional radio keys.
Your PIN code is given on the card
supplied with your Cobra 7928/26/HF
Alarm System together with the serial
number of the system itself. Please keep
this card in a secure place - not in the car and also make a note of these numbers for
any second driver’s use.
Without the PIN code and emergency
override touch key no additional or
replacement radio keys can be
programmed into the system.
All round protection is ensured with:1. Passenger compartment protection
using ultrasonic sensors (7928) or
hyperfrequency radar sensors
2. Multi-circuit engine immobilisation operates immediately the system is
armed, or passively 60 seconds after
ignition is switched OFF and the driver's
door opened, or 255 seconds after
ignition OFF if the doors are not
3. Peripheral protection to doors, boot
and bonnet using direct contact
4. Personal protection - remote control
‘panic' button on radio keys.
Many of the security functions are
integrated with your vehicle's electrical
system and we recommend that you read
the complete instruction booklet to ensure
trouble free operation.
Also for your added safety, each system
contains circuitry to ensure the alarm
cannot be switched on when the vehicle's
engine is running.
Radio Key Function
Siren Interrupt
Panic Alarm
Ultrasonic Sensor exclusion
(within 20 seconds of arming)
Button Button
Radio Keys
The security system is operated by remote control radio keys. Two radio keys are
supplied with each Cobra 7928/26/HF Alarm System. Always press the button for a full
ONE SECOND to allow the whole code to be transmitted. The small LED on the radio key
will flash whilst the button is held down. The Radio Keys should normally operate up to
3 metres from the car but range can be affected by other radio signals in the vicinity.
Radio Key
The Radio Keys are powered by a long life 3v Lithium battery
(type CR2032 or equivalent). With normal usage a new battery
should last between 3 and 5 years. Replacement batteries can
be obtained from your Cobra Dealer.
Low Radio Key
If the small LED on the radio
key flashes irregularly or only
once when the operating key
is pressed, instead of flashing
continuously, this indicates a low
Battery Replacement
1. Open the case as shown in the
diagram - levering the two sides
apart in the area marked OPEN on
the key case.
2. Remove the old battery as shown.
3. Wait for 10 seconds before inserting the
new battery, ensuring the correct polarity
(+ sign upwards) and holding the battery by
the edge.
4. Close the case firmly making sure locating
studs are correctly positioned to ensure a
waterproof seal is made.
5. The remote key should now operate
normally, but it may require resynchronisation with the main control unit.
Testing the Remote Key & Re-synchronisation
If, at any time, the remote key does not operate the system, stand close to the car and
press and hold down both buttons until the LED on the remote key goes out approximately 10 seconds. Release both buttons - the LED will come on constantly. Then
press button ‘A' for approximately 1 second - the LED will flash - this should complete resynchronisation.
In case of difficulties please consult your Cobra Dealer.
Radio Keys
Passive Immobilisation
The System will automatically arm the
double immobilisation 60 seconds after
the ignition is switched OFF and the
driver's door is opened. If the doors are
not opened the delay is extended to 255
seconds after the ignition is switched OFF.
l The LED will flash.
It will not now be possible to start the
engine, but in this instance the doors will
not lock and the windows etc. will not
close. The door trigger circuits and interior
sensor do not arm.
To start the engine, ensure the ignition is
switched OFF then disarm the immobiliser
by pressing button ‘A’ on the radio key and
then switch ON the engine within 255
To fully arm the system after passive
immobilisation, switch OFF the passive
arming by pressing button ‘A’ on the radio
key, then re-arm the system (as described
in ‘Arming the System’).
The radio keys for your Cobra 7928/26/HF
Alarm System have a ‘protected selflearning' feature which allows up to four
Radio Keys to be programmed into your
system by using its unique PIN code in
conjunction with the electronic touch keys.
All existing radio keys and touch keys
must be re-programmed at the same time
as any additional or replacement keys are
being introduced to the system. Your
Cobra Dealer will be able to carry out this
procedure for you.
Arming the System
Radio Key - pressing the operating button
‘A' will arm the system, indicated by:1. Two flashes of the vehicle's hazard
2. Continuous flashing of the LED
warning light.
3. Simultaneous locking of all doors.
l Immediately the alarm unit is switched
ON (‘armed') the vehicle is
Emergency Override
Touch Key
The emergency override touch key can be
used to disarm/ de-immobilise your Cobra
7928/26/HF Alarm System in the event of
lost or damaged radio keys. If your car is
locked use your door key to enter the car
and touch the Emergency Override Touch
Key on the contacts of the touch receptacle
- this will disarm and de-immobilise the
security system. If the system was fully
‘armed' the siren will sound until
disarming has taken place. The car can
then be started in the normal way.
After switching ON (‘armed') a period of
approximately 45 seconds will elapse
before the system is fully active. (This is a
‘setting-up' and ‘test period').
When the alarm is fully active it will be
triggered by:1. Opening a door, boot or bonnet (Direct
Contact Switches).
2. Movement within the vehicle
When triggered the Electronic Siren will
sound at 118dB and the hazard lights will
flash for 30 seconds - at the end of this
l Up to four Emergency Override Touch
Keys can be programmed into each
Cobra 7928/26/HF Alarm System.
period the system will close down and
automatically re-set to provide protection
against a further attempt by an intruder to
enter the vehicle.
Siren Interrupt
Pressing button ‘A' whilst the siren is
sounding will turn the siren off. The Alarm
System ‘status' - i.e. ‘armed' - will not be
Disarming the System
On return to the vehicle, pressing
operating button ‘A' on the radio key will
disarm the system. This is indicated by:-
Panic Alarm/
Personal Protection
1. One flash of the hazard warning lights.
Pressing the auxiliary button ‘B' will sound
the siren for 10 seconds when the alarm
system is in the ‘armed' state.
Note: If the system has been triggered
during your absence the hazard lights will
flash 4 times and the buzzer will sound 4
Note: This function will not be operational
during the 40 seconds set-up time
required for the system to become fully
active after it has been ‘armed'.
2. Extinguishing of the LED warning light
- see note.
3. Unlocking of all doors.
Note: If the alarm has been triggered in
your absence a ‘status history' will be
displayed by the LED warning light and is
indicated as follows:-
Volumetric Protection
Single pulse flashing of LED: One
alarm state caused by opening of the
boot, bonnet or doors.
Ultrasonic Sensor (7928):
To arm the system without utilising the
Ultrasonic interior sensor, press the
operating button ‘A' in the normal way
then, within 20 seconds, press the
auxiliary button ‘B'. This allows all other
protection circuits to remain active whilst
windows can be left partially open (for a
dog inside the vehicle etc.). This command
is indicated by a ‘beep' from the siren.
Twin pulse flashing of LED: One
alarm state triggered by accessory
hyperfrequency radar sensors
Triple pulse flashing of LED: Alarm
state triggered by the ultrasonic
sensor or optional glass break (7928).
Quadruple flash repeated regularly:
Alarm state caused by an attempt to
start the car.
Note: This display can also show multiple
triggering and other system diagnostics please consult your Cobra dealer in case of
any difficulties.
Illuminated Entry
On disarm the system will switch ON the
courtesy light for 30 seconds, or until the
ignition is switched ON.
This display is extinguished when the
ignition is turned on.
Trouble Shooting
Your Cobra 7928/26/HF Alarm System
should have been installed by a fully
trained technician. In the unlikely event of
a problem occurring with it please contact
your supplying/installing Cobra Dealer for
assistance. If this is not immediately
possible the following notes may be of
help:Symptom: Radio Key will not ‘arm' or
‘disarm' system.
l The Radio Key battery may be flat (see
notes on Low Battery Indication and
Changing Battery).
Symptom: The radio key may require
l See Testing the Remote Key and Resynchronisation section.
Symptom: Alarm has triggered for no
apparent reason.
l When you ‘disarm' the alarm the
diagnostics code will be displayed by
the LED warning light. If direct contact
triggering is indicated then switches in
doors, boot or bonnet may need
adjusting - please consult your Dealer.
If showing Ultrasonic triggering please
check that all windows, sunroof and air
vents are closed and ensure that there
are no loose moving objects (or
animals) left in the vehicle. If the
problem persists contact your Cobra
Dealer for assistance.
Checking the Alarm
You should check your Cobra 7928/26/HF
Alarm System on a regular basis - once a
week is recommended.
1. Direct Contact Check: Arm the system
and exclude the ultrasonic sensors wait 45 seconds.
l Opening any of the vehicle doors, boot
or bonnet will trigger the system and
the siren will sound. Disarm the system
from the radio key and repeat the
process for each door, boot and
2. Ultrasonic Sensor (7928) /
Hyperfrequency Radar Sensor
(7928HF) Check:
Whilst remaining seated in the car with
doors and windows closed - Arm the
system and wait 45 seconds.
l Rapid movement of your arms should
trigger the system. Disarm in the
normal way.
If at any time your alarm does not appear
to be operating correctly please refer to the
‘Trouble Shooting' section or, if in any
doubt, contact your supplying/installing
Cobra Dealer.
Pt. No. 908 001A
Rev. 06/01