NHTSA said the fine was levied for the under-reporting of vehicle crashes, deaths and injuries tied to Fiat-Chrysler vehicles.
"We need (Fiat-Chrysler) and other automakers to move toward a stronger, more proactive safety culture, and when they fall short, we will continue to exercise our enforcement authority to set them on the right path," said U.S. Transportation Secretary Anthony Foxx in a statement.
The automaker was hit earlier this year with another $70-million fine linked to the improper handling of 23 recalls involving 11 million vehicles. The vehicles included the 1993-'98 Jeep Grand Cherokee and 2002-'07 Jeep Liberty SUVs, which were recalled for faulty fuel tanks that could catch fire if the vehicle was struck from behind.
Fiat-Chrysler told Edmunds it "accepts these penalties and is revising its processes to ensure regulatory compliance."
It added: "However, FCA US is confident that it identified and addressed all issues that arose during the relevant time period, using alternate data sources."
Fiat-Chrysler is the fifth vehicle manufacturer in the past 14 years penalized by NHTSA for failure to meet early-warning reporting requirements.
NHTSA is the federal agency responsible for ensuring the safety of 250 million motor vehicles in the U.S.