Federal safety agency has expanded its investigation of Tesla’s Autopilot system.

The federal government's top auto-safety agency is investigating if the technology poses a safety risk

An engineering analysis is a more intensive level of scrutiny that is required before a recall can be ordered by the NHTSA.

The analysis will look at whether the system can prevent drivers from diversion from the road and engage in other risky behavior while using the system.

The NHTSA didn't know if defects in the system could cause cars to crash.

There are 830,000 vehicles sold in the US. The Model S, X, 3, and Y are included.

The agency looked at 11 incidents in which the autopilot-equipped cars crashed into emergency vehicles that were parked and had their lights on. NHTSA said Thursday that it became aware of 191 crashes that needed to be investigated more closely.

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