The probe includes about 87,000 of the cars from the 2011 model year that have 3.6-liter V-6 engines.
The National Highway Traffic Safety Administration says that it has received 15 complaints that the engines stall without warning while coasting to a stop.
The probe could lead to a recall. The safety agency says it's looking into how often the problem happens.
NHTSA hasn't received any reports of crashes or injuries stemming from the problem, the agency said in documents posted on its website Friday.
Chrysler spokesman Eric Mayne says the company is working with the government. He says engine performance can be affected by many things like software and fuel quality. Mayne says the 3.6-liter engine is in 12 Chrysler models and has traveled millions of miles without problems.
Owners who suspect problems with their 200s should take them to dealers for testing, Mayne said.