Audi A4 Avant 1.9 TDI - Intermittant Immobiliser Issue?

[area6334]

Hi guys - this is my first post and as an inexperienced Audi owner, I was hoping someone could help me!

Recently, I bought a 1997 Audi A4 Avant 1.9 TDI SE Auto - and I'm absolutely loving it so far - cannot believe I've not had an Audi before.

There is 1 small problem I've been experiencing though relating to the immobiliser. Basically, I insert the key and turn the ignition on and the glow plug and immobiliser lights appear. I wait for them to both go out and most times, it's all fine, they go out and I start the car.

However sometimes after the lights go out, the immobiliser light just flashes and the immobiliser is still activated and I can't start the car for more than 2 seconds. I take the key out and hear the 3 little bleeps which I believe mean the immobiliser is active and then try again - sometimes it's fine straightway - the most attempts its taken so far is 6. It has always been getting there in the end and I appreciate in the grand scheme of things, it's a tiny issue but obviously I'd love to get it sorted to get my car perfect.

I've tried a spare key but that doesn't seem to make a lot of difference.

Does anyone have any ideas? Anyone experienced this before and solved the issue? Any help would be greatly appreciated!

Thanks so much

Andy

[towcestervag]

sounds like a reader coil fault
remove steering column covers and remove the connector to the reader coil
seperate connector and tighten the terminals in block

[trickyfocus]

Be aware that airbag's are dangerous........
Remove the battery termanels before starting work...

[cusford]

what if the below doesn't work? i've tried this and my light will flash for ages, i keep turning the key, and it takes ages for it to work

[Alan02]

Possibly Low Signal from the Key ? Have you tried using your spare for a while to compare?
As mentioned the reader Coil could also be suspect.

[cusford]

the only spare i got was one that was cut at a shop, so no immobiliser chip in it.
would vagcom pick up the fault do you think??