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i30 N i30N UK Alarm System - Earlier (MY18 & early MY19) cars AKA “Sunglasses Holder Version”


Staff member
Feb 4, 2019
This is a general info/what we know type of information "dump" for the UK only supplied problematic 2-1 alarm system that the earlier cars came fitted with.
We currently have a 22 page (at time of writing this) thread for general discussion on the alarm issues/fixes and some of the info is confusing or just lost in a realm of mis-information.

What is it then?

It is a Cobra 4615 Thatcham Cat 2-1 Wireless Alarm system with the optional Cobra A5462 Microwave Sensor.
The system did not come fitted from the European factory. It was fitted by Vodaphone Automotive at the UK docks, obviously sub-contracted by Hyundai UK.

It sets from the car fob buttons. Using the physical key in the door lock does not set the alarm.

I’ll spare the detail of these models as Google can give you answers but suffice to say, they are cheap, they are nasty.

The main 4615 alarm provides exterior protection for the following:
  • Doors
  • Bonnet
  • Tailgate
The 5462 provides Interior protection:
  • Microwave (Hyper Frequency) Sensors
  • Interior Movement
The siren is a “wireless” type with battery back-up. More on that later.

Let’s start with the interior…….

Right then, my alarm goes off if it’s windy, hot, cold, a small animal trumps next to it. Must be the sensitivity right?

Not really, Microwave sensors do not pick up air flow or temps, Just movement. Check the interior for insects etc. Closing the air vents will just stop physical objects entering the car. It is not atmospheric conditions setting the interior sensor off!

I fitted LED interior lights to my car, my streetlight is a newer LED one, my neighbour has a PIR security light that’s on/off all the time. Anything to do with interference and my alarm going off?

Nope, not likely.

Can the sensitivity be adjusted?

Yes, easily.

Sensor is up near the rear interior light:

Pop the lens cover out to gain access to the two screws holding the unit in.
Get a trim removal tool/use fingers to pull the light unit out and unplug - its quite tight.
Put your hand up in roof lining towards the front of car and there is the £40 delight that is the microwave sensor. It'll be velcro'd to the roof panel.
Adjust sensitivity using a small jewellers screwdrive (or similar)

Can the interior sensor just be unplugged?

Yes, easily. It makes no difference to the main alarm operation. It is just an optional add-on module.

Can the interior sensor just be turned off?

Yes but it has to be done every time you park up. It cannot be permanently disabled without drastic action (see above).

Why didn’t they just fit switchable Ultrasonic sensors in the interior instead like almost every other alarm system for the last 20 years (and the newer cars which now don’t have the sunglasses holder)?

More fitting time at the docks! (Extra cable running, removing bits of interior trim etc). Time = Money.

Onto the exterior……

Loads of cats are always around my car/people are always walking past etc. Are they setting it off?

Nope, the system doesn’t have shock protection or any proximity sensing. Someone can run up and down the car if the wanted and no alarm will be triggered.

Can I adjust anything to help minimise false alarms?

This is very simple, the alarm utilises all existing sensors/switches via Canbus connection input/outputs. Therefore, there isn’t much to check here. Moving on…..

But what about the siren……?

The siren unit is fitted in the engine bay with the following 2 main wire connections: Live and earth.
The Live goes straight to the battery for constant power and the earth is self-explanatory.
There is an RF Antenna with provides the wireless connection to the main unit (which also has an RF Antenna….obvs).
Here’s a bit of info regarding the RF Antennas from Cobra themselves:

“The RF antennas positioning (for both the main unit and the siren) is crucial for a proper system’s performance. They must not be cut, wrapped, connected to any other cables or to the vehicle body and they must be kept separate from the main wiring harness and as far as possible from metallic parts”.

RF Antennas? That means Bluetooth then, everyone keeps bashing on about the Bluetooth connection?

There is zero mention of Bluetooth in the Install Manual or User Manual for this alarm series or anywhere online. That’s odd as normally any Bluetooth enabled device must have Registered Bluetooth symbol/Reg Marks on their manuals. (Like the handbook for your car, it’s full of them). So are misinformed people (dealerships) just using the term “Bluetooth” to describe the RF Antennas?

Right then, my siren is wailing its tits off all night and Big Dave from down the road wants to cave my head in, I can just remove the power to the siren to shut it up, right?

Hmmmmm, careful with this. The siren unit has an internal battery back-up. Therefore, just removing the power connection to the car battery isn’t fool proof. It will still sound off…..probably.

Alright smart-arse, lets pull the connector out from the siren unit then?

Go for it! But be aware that battery back-up sirens normally have “Cable Cutting Protection” to signal a sabotage attempt. If you are going to try this then I recommend you fully remove the siren module as well and move it as far, far away from your car as you can before you try and arm the system again!

But if I do that, does the system still arm and not cause any issues? Or does the main unit and siren unit have to stay ‘paired’ to enable my car to lock/unlock/start properly?

Dunno, nobody has got that desperate yet?! Try it and do let us know.

Anything I can do to troubleshoot the siren unit?

Check the connections, give them a blast with contact cleaner, check and clean RF Antenna, check its position and make sure it’s pointing towards the dash and stable. There is talk that the siren units can be relocated as one of the many “fixes”.

Here’s another snippet of info from the Cobra Install manual regarding siren location:

“It can be installed in the engine bay or inside the vehicle far away from heating sources paying attention to keep the main connector oriented down”.

So the connection between siren and main alarm module is “wireless”?! Why didn’t they use a “wired” connection? Wired is better than wireless, always!

Same reason they didn’t bother fitting Ultrasonics in the interior. Longer fitting time on the docks = Money, money, money!
Someone has had their system converted from wireless to wired but they are in a lucky majority of one it seems!

Last edited:


Staff member
Feb 4, 2019
Any other questions.....?

What does that silly little LED button do on the driver’s side lower panel?

You should have had an alarm manual/info sheet supplied with the car. If not, whinge to Hyundai or ask nicely on the forum and somebody may help you out.

What does the number of flashes on the above LED signify?

Again the supplied alarm info sheet tells you all you need to know. The number of flashes indicate the circuit responsible. But for completion sake:

1 = Doors
2 = Bonnet
4 = Ignition Hot Wire Attempt
5 = Tailgate
7 = Additional Sensors (Microwave)

Important! The LED will continue to flash until the ignition is next switched on.

What do the beeps mean when I unlock the car then?

Your alarm has triggered. Nothing more, nothing less.

Should my indicators flash when my alarm is going off?

Yes, if it is a ‘true’ alarm trigger then they do. Don’t believe me, lock your car with a window open and the wave your hand in the interior to set off the alarm. Your indicator lights should be flashing along with the ear piercing siren. Maybe wear ear protection.....

But they don’t generally though?

Yeah, that’s a ‘ghost’ alarm or a faulty trigger. It’s what 99.9% of the alarm triggers are. Keep up!

What’s the Vodaphone card left in my car for?

Vodaphone installed the alarm on Hyundai’s behalf so all this shows is the unique PIN code for your particular alarm to deactivate it temporarily. There is no SIM card in these alarms. Again, refer to the info sheet. It explains it all.

Could vibrations/other cars/electrical equipment set the alarm off?

Possible, cars that have also have microwave sensors can interfere with each other. Microwave sensors also work on the same frequency as Wi-Fi and Bluetooth so security cams, doorbells, modems etc might be an issue. Clutching at straws a bit here though aren’t we?!

Vibrations from a nearby passing car could theoretically set it off there is a poor connection or badly position RF Antenna. Again, straw clutching.

In the engine compartment fuse box there is F27 BURGLAR ALARM HORN, can’t I just pull this?

If only it was that simple but alas that has nothing to do with the UK alarm system.

You can remove it, but it will just kill the horn. Nobody wants to voluntarily lose their horn yet do they (age gets us all eventually)?!

Why have you put all this info on the internet you dick?!

Sorry about that Snowflake but the alarm type is clearly printed on the Hyundai supplied information sheet (Vehicle Alarm System – Vodaphone Automotive 4615 TQA260). Through persistent investigation/use of the internet and using basic human senses (sight being the main one) all this info is readily attainable.

So you’re an alarm expert then?

“I find your lack of faith disturbing” © D.Vader 1977
No, but I’m pretty sure there is more correct info here then your dealership will ever know and certainly more than Hyundai/Vodaphone will ever let on.

So what will my dealership do for me (generally in this order)?

1) Adjust sensitivity (10min DIY job, save yourself a visit).
2) Move/rotate the siren unit possibly.
3) Check it over (i.e do nothing else after performing the first two).
4) Confuse the customer (that’s you that is) by telling them any old nonsense about antenna’s, Bluetooth, adjusting sensitivity again, checking connections, “It never went off in our possession, so not much we can do” etc.
5) “Monitor it and check it over” – i.e do nothing with it all.
6) Give up and get Vodaphone involved.

What do I do if my alarm just won’t shut up?

1)Lock it with the key not the fob. Works 99.9% of the time.
2) Leave it unlocked (not ideal).

But I’ve locked it with the key and it’s going off again?

Yeah that happens sometimes, means it’s properly got its knickers in a twist. Fire up the engine (go for a quick drive if you have to). Then just lock it again after.

It’s going off and even unlocking the car won’t stop it. Help!!!

Same as above, start the engine. Engine cycling seems to “Hard Reset” it generally.

Tech Info (From the Install manual):


Rated supply voltage: +12 V DC
Operating voltage: +8 V ÷ +16 V DC
Current consumption (central unit, LED and siren) disarmed: 8 mA
Current consumption (central unit, LED and siren) armed: 12 mA
Central unit operating temperature: - 40 °C + 85 °C
Siren operating temperature: - 40 °C + 85 °C
Self power supply: Lithium Battery 6 V 1300 mAh
Loudspeaker sound pressure level: >115 dB @ 1m
Siren sound pressure level: >114 dB @ 1m
Central dimensions: 91x69x35 mm
Siren dimensions: 113x79x45 mm