help with trouble codes 94 gt

[94gt5.0]

I posted a video on YouTube I don't know how to post a link I'm using a cell the video is called 94 mustang gt trouble codes help I tryed reading these but I don't get it video by ian241986

[94gt5.0]

Anyone

[94gt5.0]

http://m.youtube.com/index?desktop_uri=%2F&gl=US#/watch?v=oi9uaq8YF3g

[cwh19]

18 ignition diagnostic monitor (IDM) circuit failure.

That's the only code I saw.

[94gt5.0]

So what does that mean

[94gt5.0]

Any help with this code I am having problems timing it