Engineers at NASA's Jet Propulsion Laboratory said the "flip of a bit" in the memory of an onboard computer appears to have caused the disruption. A value in a single memory location was changed from a 0 to a 1.
Officials said they plan to reset the bit to its normal state Wednesday.
The spacecraft was shifted into a mode that transmits only spacecraft health and status data after the unexpected change in the pattern of returning data. Although the spacecraft is in good overall technical health, NASA said the change in the data return pattern prevented mission managers from decoding science data.
Voyager 2 was launched in August 1977 about two weeks before its twin spacecraft, Voyager 1. The two spacecraft are the most distant human-made objects, now about 8-10 billion miles from Earth.
"Voyager 2's initial mission was a four-year journey to Saturn, but it is still returning data 33 years later," said Ed Stone, Voyager project scientist at the California Institute of Technology in Pasadena.
The Voyagers were built by JPL, which continues to operate both spacecraft.