Technical Waning/Advisory light help

[ourden]

I have a 2003 JTD and today a warning light appeared, it was on the left hand side of dash, yellow and a padlock symbol. I turned engine off then on & it never returned.
Would like to know what it was though?

 

[T14086]

immobiliser light, normally appears when the key code has not been read correctly by the reciever (aerial)

 

[ourden]

immobiliser light, normally appears when the key code has not been read correctly by the reciever (aerial)

Cheers just had a Toad alarm system fitted must get it checked.
Thanks