Immobiliser Replacement

There are two types of TVR out there; those that have had the original immobiliser replaced already, and those that haven’t – yet.
We’re not talking “dodgy TVR electrics” here. These immobilisers were warrantied for 7 years- these cars are 20+ years old now. So actually, they’ve done quite well!

Warning signs your Immobiliser is faulty

The general consensus is, these original units don’t just suddenly die completely; they die a slow death, and as such there are warning signs. The symptoms mine was failing, was that the starter was not engaging. I would hear the fuel pump prime, but on pressing the start button.. nothing would happen. It would take a few attempts, and then it would suddenly come back to life. It only seemed to happen on a cold-start.
Hearing the fuel pump prime each time led me to misdiagnose this as a starter motor problem. I now have a new starter motor, plus a perfectly working spare. 😒
So how do you know if it’s the immobiliser at fault?- it’s not easy. There are 3 separate systems controlled- ignition, fuel pump and starter motor. The starter motor is usually the first to go due to it having the highest load through it.

My advice: at the slightest sign of trouble, get it replaced- it’s just a matter of time anyway.

21st Century Immobiliser and Alarm

There aren’t that many people who specialise in replacing these immobilisers in TVRs, but I was lucky enough to catch Carl Baker while he was in the UK.
So what does the new one do?

  • It has a 50% reduction in parasitic battery drain – in other words you can go on holiday for 2 weeks, and not come back to a flat battery.
  • It has a proximity sensor, so that when you are in range of the car, the car is not immobilised- meaning you just press the start button- no faffing around disarming or rushing to beat the time limit before it arms again.
    It’s smart too- the proximity sensor will go to sleep if it hasn’t moved for a while- so if your keys resting place in the house happen to be in range of the car, all is good.
  • There is a button on the remote to open the boot.

It’s like a modern car!
old alarm immobilisernew alarm immobiliser
Old on the left, new on the right. (Serial numbers etc obfuscated)
Side topic: what do you make of the scribble on the fibreglass panel?
These cave drawings & scribbles are quite common. Builders from the factory often signed their name, or sometimes left a cave-drawing. Someones initial maybe? or were they interrupted while drawing something else? 🤣

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