ODB read error

[fishermanbri]

Appreciate any constructive input on this.

Question 1:
Has anyone ever had trouble pulling ODB II codes on a 2002? I have a reader that I know to be working but only am able to pull 'error' from my X5.

Question 2:
Attempting to pull code because idle is rough to the point of stalling, believe one of my ignition coils has gone bad. SES light is on. As long as fuel is being fed to the engine (accelerating) I wouldn't even know I have a problem, short of the smell of unburnt fuel. If I take my foot off of the gas pedal while at speed it immediately goes into rough idle. Presuming this to be enough information could someone confirm ignition coil as probable problem?

Thanks for any help.