2001 I30t Tach Problem

[Fastpants]

Hi All!

I just dropped off my dear ol' Dad at the dealer to pick up his new (to him) 2001 I30t. GORGEOUS Car!! Black/Taupe, Bose, Navi. The whole bunch a' petunias! Sweeter than candied gravy.

The only, and I mean ONLY, flaw in the entire car is that the tach won't work. Not intermittently. Not sometimes. Just dead.

Therefore I was hoping some of you fine folks 'round these parts could suggest possible causes so we can get that squared away and this baby can be 100% Super Positive Spectacular!!!

Thank you all so very much and my Pops thanks you too!