Emissions light just came on 2006 Jetta 2.0TDI
 

Hi I am new to this so here goes
My Jetta 2.0TDI has 25K miles and the emission light has just come on what could I check myself I am a trained VW Audi mechanic but that was 25 years ago so need a bit of help here and dont really want the nose bleed related to charges at the local vW shop

any help or pointers would be greatly appreciated

RE: Emissions light just came on 2006 Jetta 2.0TDI
 

check for loose or broken vacume lines
have someone pull the code