Hello,

Yesterday I had the battery changed in my key fob as the central locking wasn't working.

I went to my car, started it and drove it 1/4 of a mile. Stopped, turned the car off and left the keys in the ignition while chatting to someone. The lights were switched to the 'on' position. We needed some light so I switched the ignition on so dipped beam came on.

I presume I had a weak battery as when I tried to start it, there wasn't enough juice to turn over the starter motor but I noticed the car immobiliser light (yellow light in the shape of a car with key underneath) was flashing.

As the dash lights were still on, I tried to bump start the car to no avail. I then tried with Jump leads, which had the same outcome.

I got towed home, charged the battery over night and have re-fitted today. The car turns over, starts and then immediately stops with the immobiliser light still flashing. This is happening with the 'main' key I use which had the new battery and also the spare key I have.

Has anyone had this problem before, and has having the battery changed in the key caused this?

I need a fix asap as I have no other means of a car.

Any info would be gratefully appreciated on how I could sort this and get going again.

Thanks.

Changing the battery in the key is not connected to the immobiliser as the chip in the key isn't powered by that battery.

 

It shouldn't happen but occasionally does, if the main battery voltage drops too low, the speedo/immob can loose it's pairing with the key, you'll need vagtacho to get the immob pin number then VCDS to re-pair the key & immob

Changing the battery in the key is not connected to the immobiliser as the chip in the key isn't powered by that battery.

 

It shouldn't happen but occasionally does, if the main battery voltage drops too low, the speedo/immob can loose it's pairing with the key, you'll need vagtacho to get the immob pin number then VCDS to re-pair the key & immob

Thanks for the reply, I'm sorry but this is all new to me. Is it something any auto electrician can sort or do I need main dealer?

Will I be looking at an expensive bill once rectified?

Many thanks.

An Auto-electrician with the correct kit could do this, should only take 20 mins so the cost shouldn't be too expensive 

On 14/01/2017 at 19:36, nige8021 said:

It shouldn't happen but occasionally does, if the main battery voltage drops too low, the speedo/immob can loose it's pairing with the key, you'll need vagtacho to get the immob pin number then VCDS to re-pair the key & immob

 

Hi, I left the doors open today because I'd noticed the carpets were damp and then forgot I'd done it with the result that the battery got run down.  When I tried to start the engine, it turned over sluggishly and wouldn't fire.  I tried jumping it from another car but then there was nothing, no clicking from the solenoid, nothing from the starter motor. Could this be the same thing?

Just checked and the immobiliser light is on, so it looks like that's the problem.