Cobra 8509 Immobiliser

The first thing you notice with the Cobra 8509 Immobiliser is its size, or should that be lack of size! It is tiny and certainly the smallest Immobiliser that I am aware of. This makes it an installers dream as the hiding locations are almost limitless.

The Cobra Immobiliser is completely separate to the alarm. It is connected via a coded bus wire so can be added to most of the new generation of Cobra alarms. This makes the 8509 effective for two reasons:

The first is that it does not contain any alarm electronics such as hazard light relays which can often be a dead give away to the modules location. Listening for the clicking relays is a trick I often use to find an immobiliser, once I have silenced the siren I simply listen to where the sound is coming from which quickly narrows down the location area.

The second advantage is that due to its lack of alarm circuitry it is much smaller, making it much easier to hide.

Cobra V Mongoose – The Alarm World!

Mongoose M60 looks big and cumbersome!

Given that the Mongoose M60 is one of the best-known alarms in New Zealand I felt it would be a good benchmark to test the Cobra against.

In the animal world, it is well known that a Mongoose one of the few animals capable of fighting the great snake. I have also noted that Mongoose NZ has a video of a Mongoose killing a Cobra on their Facebook page. However, in the world of car security, the Cobra wins hands down. The Mongoose is light years behind the Cobra if it was not for good marketing on the part of Mongoose I’m sure it would be an extinct relic!

Anyway, I’ll get around to reviewing the Mongoose Immobiliser in the coming weeks,  right now I’m here to review what the Cobra has to offer…

Attack-Proof Security Housing

The main thing to get excited about is that the Cobra 8509 has an attack-proof security housing. It is the only Immobiliser for sale on the NZ market that I have not been able to get inside and bypass.

The 8509 also complies with Thatcham standards which makes the NZSA Star rating system look shamefully outdated.

It is worth noting that you will not find AVS, Dynatron, Mongoose, Steel shield, Meridian or Uniden Immobilisers outside of New Zealand or Australia as the standards set here (or should that be lack of standards) are not accepted overseas.

Cobra 8509 Immobiliser

Obsessive Rating: Perfection

The 8509 is simply brilliant.

Small, attack proof and no clicking relays to give away its location.

The only weak point would be the Installer

If I was a Mongoose I would be losing the will to live right now. Bragging rights clearly go to Cobra so I’d be working hard on making a better product rather than spending time on Facebook!

Note: The 8509 can only be installed in conjunction with the following Cobra alarms:


In other words, it can not be installed without one of the above systems.

If you require an immobiliser without an alarm then look at the Cobra AC8510.

This entry was posted in Car Security, Cobra, Immobilisers, Mongoose, Reviews and tagged , . Bookmark the permalink.

12 Responses to Cobra 8509 Immobiliser

  1. corin says:

    Thanks for a very informative review and discussion pages on pros and cons of seems there are a lot of very poor ones out there!

  2. Julian says:

    Hey, thanks for taking the time to read it and comment. The blog would be pointless if nobody noticed it!

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  5. xr6CHuRBo says:


    Will the Cobra 8509 Immobiliser marry up to/ or be able to be modified someway to mongoose m80g? like the idea of the mongoose sms module… or can u recommend one thats is close to or has it all?


  6. Julian says:

    G’day XR6CHuRBo,

    You wouldn’t happen to drive a Falcon by any chance?!!!

    The Cobra 8509 connects via a bus data line so will only work with the latest generation of Cobra alarms. A separate transponder Immobiliser is always a good option!

    In regards to the SMS module. If you can wait I’m in the process of trialing some which should be better value but won’t be selling any until I’m happy. Watch this space…

  7. Julian says:

    This from Rick:

    This would have been great on the Cobra 8509 blog page except I don’t know if vistors can post images…

    Mongoose. That's a funny name!

    I’m sure Mongoose thought it was a great hoot to name themselves after the animal notorious for owning Cobras (except they they forgot the small detail of making a superior product).

    The image was on this blog: (doesn’t say it’s copyrighted 🙂 ).

    I thought it complemented the “Hiss off” slogan nicely.

    You’re right, you can’t post images at this stage, but you’re most welcome to add them to the Facebook page. I’ll see if I can change this sometime.

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