Key Signal, immobiliser problems

[acmo]

Hi all, been to help a mate with a 98 A4 tdi with immobiliser problems. Starts and stops straight away. After a vcds scan, instrument cluster - 01176 key signal too low.
Engine - 17978 start blocked by immobiliser.
I have done a reboot by disconnecting battery.
Tried both keys
Checked connection on back of instrument cluster.
Ross tech wiki suggests it's the read ring around the ignition, is this a common problem? Going to have another look tomorrow when it's not raining.
Has anyone experienced this before?

[acmo]

Got in to the reader coil this evening and checked wiring right through to the dash, all intact.
Key signal fault has now gone but 'engine start blocked by immobilizer' is reoccurring. Im at a loss now of where to look next........

[jtonthebike]

Buy an immobiliser removal tool/dongle from ebay/China? 5mins and the immobiliser will be disabled, if you really want one, fit a 3rd party one. Done. Easy.

Sent from my SM-G900F using Tapatalk

[jtonthebike]

It could also be the key simply needs to sync, after I'm guessing so many attempts to start the car, the codes will have rolled on - but - this is a guess

Sent from my SM-G900F using Tapatalk