A Sydney court has heard a mother forced her 13-year-old daughter into a sex act with a truck driver in exchange for diesel fuel.

The girl's mother and the truck driver have been found guilty of a combined total of more than 60 charges.

During sentencing submissions for the 31-year-old driver, Downing Centre District Court heard that the girl was abused several times in 2004.

The court heard that on Fathers' Day her mother dropped her off on the F3 freeway between Sydney and Newcastle and forced her into the cabin of the man's truck.

Prosecutors say the mother later siphoned diesel from the truck in exchange for the child.

The prosecutor said they should face similar sentences because the offences were part of a joint criminal enterprise.