Voyager 2 is on it's way out of the solar system, 44 AU from Jupiter at the time of the impact. The planetary radio astronomy (PRA) experiment will be monitoring radio emissions in the 1 KHz to 390 KHz range with a detection limit of 10^19 to 10^20 ergs. PRA will sweep through this spectrum every 96 seconds. The Voyager 2 imaging system will not be used.
This was exerpted from a paper titled "Comet P/Shoemaker-Levy's Collision with Jupiter:
Covering HST's Planned Observations from Your Planetarium". To see the
entire paper, click here.