Hi lads,

I bought one of these mini diagnostic machines online, and I'm looking for a bit of advice....

I noticed it had a function "mileage correction", so I decided to test it out on my audi a4 2001....

(genuinely was only trying it out before anyone attacks me- car has full service history)

But when i pressed enter on it nothing happened, and afterwards car would not start!!!!!!!!!!!!!!!!

Panicking, I tried everything but nothing worked, in the end I disconnected the battery and reconnected it, and it worked with the changed mileage (which I have since put back....)

Does anyone know why this happened, as in why it would not start, did it reset the alarm/immobiliser or what???

Cheers!

Because the car thought it's mileage had gone back, so went nuts

The immobiliser data is stored in the same area as the mileage in the cluster. Immobiliser system works with three things, key, cluster and engine ECU. Engine ECU won't allow the car to run without authorisation from the cluster which you upset until you disconnected the battery and rebooted the cluster.

Be very careful with tools of this kind. They can damage your cluster beyond repair.