Producers wanted Steve Guttenberg (Newton Crosby in Short Circuit (1986)) to commit to the sequel without a script, but he declined. Twenty years later, Guttenberg expressed in an interview that he regretted turning down the chance to star in this film.
The sad music track in the film that was played in the background, after Johnny 5 is attacked, was influenced by "Gymnopedie No. 1" by Erik Satie.
While it is usually accepted the city in the movie is New York City, Oscar gives Number 5 a tourism guide with St. Louis on the cover. (It was filmed in Toronto.)
A third "Short Circuit" film never happened, due to this film getting mixed reviews and "disappointing" box-office returns.
When Johnny 5 gears up at the Radio Shack and gets ready to go after Oscar and the thugs, Johnny 5 gives himself a Mohawk. it was written as a nod to Taxi Driver (1987), in which Travis Bickle (Robert De Niro), a mentally unstable taxi driver gives himself a Mohawk before he sets out to assassinate Senator Charles Palatine and save teenage prostitute Iris Steensman from her pimps.
Jack Weston's final film. He worked on this project after production was completed on his previous films, Dirty Dancing (1987) and Ishtar (1987). After completing production on this film, Weston retired from acting. He passed away on May 3, 1996 at the age of seventy-one.
In 2013, a remake of the original film was announced as being in development. Fisher Stevens stated his interest in returning. The proposed remake was said to be darker in tone than the original movies.
According to Johnny 5, he had his memory upgraded to 500mb between leaving Astoria and going to the city.
Stephanie Speck from the first movie, played by Ally Sheedy, has a short audio role but on a cassette tape, and she makes a quick reference to Newton Crosby. Another heavy reference is made about Ben Jahveri and Newton's working relationship and background during Fred Ritter's attempted sale of Johnny 5 to a corporation.
The location of the city of the film, while never spoken, is hinted as being New York City through statements of the characters. Furthermore, as Sandy is using Ben's impromptu musical cues to locate him, the song "On Broadway" is played, a familiar street of the Big Apple.
The exterior of the warehouse that Ben and Johnny 5 are working out of was filmed on Sorauren Avenue in Toronto.
The opening scenes where they are selling on the street is in reality at Yonge and Dundas Street in Toronto. Most of the buildings in the scene are no longer there. The Hard Rock Café building is still there but the Hard Rock closed in 2017, and will be a Shoppers Drug Mart.
Johnny 5 gearing up at the Radio Shack and getting ready to go after Oscar and the thugs, which Oscar says "Alright! Let's party!" is a nod to the gear-up scene in Commando (1985), in which John Matrix (Arnold Schwarzenegger) gears up and gets ready to do battle with Bennett, Arius, and their men. In the final fight with Bennett (Vernon Wells) Matrix says to Bennett, "Come on, Bennett. Let's party!"
After the events of the first movie, Nova Robotics was shut down and the remaining robots were destroyed.
All the things said in Pig Latin are: "act scared" (said twice), "get behind him" (said twice), "keep him busy", and "screw you bozo".
During the climax of the film, Johnny 5 says, "Suspect vehicle turning east on Lakeshore", before cutting to a shot of Lakeshore Boulevard in Toronto. It suggests the film's producers considered this film set in Toronto.
The alarm system seen on the wall outside of the Radio Shack was purchased from SSI 2000, a security equipment wholesaler.