Error Code 34 - 96 XJ

My buddy is getting error code 34 on his 96 XJ. I know this translates into:

34*
¤ An open or shorted condition detected in the Speed Control vacuum
or vent solenoid circuits.
¤ Speed control switch input below the minimum acceptable voltage.

But what does that mean in english?

At a guess, I'd say it means he has a vacuum leak. Especially since vacuum leaks are a frequent problem with the XJ. He should start by checking the vacuum "blimp" located behind the front bumper, passenger side, and the vacuum lines that run from that beneath the battery tray.