Tesla CEO Elon Musk hit back Monday at a report that said Tesla ignored engineers who urged the company to add more sensors to its vehicles.

"This is false," Musk said Monday on Twitter, referring to The Wall Street Journal's report that Tesla refused calls from its engineers to add more safeguards into its Autopilot driver assistance system because it cost too much.

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"We stand by our reporting," a spokesperson for Dow Jones told CNBC.

In a second tweet, Musk said the probability of fatally crashing a Tesla is far lower than it is for other vehicles.

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The Journal report said engineers were worried there were not enough safeguards in the system and proposed adding sensors that ensured drivers kept their eyes on the road and hands on the wheel. However, senior executives, including Musk, concluded they weren't necessary, the paper said.

Cost was one of the reasons the Journal gave for why Tesla executives rejected the idea. The report also said top Tesla executives thought the devices were ineffective or would annoy drivers too much.

In his Tweet, Musk said the eyetracking systems were rejected for being ineffective.

"Everyone at Tesla is not only encouraged, but expected, to provide criticism and feedback to ensure that we're creating the best, safest cars on the road," Tesla said in a statement. "This is especially true on the Autopilot team, where we make decisions based on what will improve safety and provide the best customer experience, not for any other reason."

Tesla added that it designed Autopilot to deliver an escalating series of warnings to the driver and disengage the system if the warnings are ignored.

"We've explored many technologies and opted for the combination of a hands-on-wheel torsion sensor with visual and audio alerts, and we will of course continue to evaluate new technologies as we evolve the Tesla fleet over time," Tesla said.

Tesla's Autopilot, a driver assistance system, has come under scrutiny after some high-profile accidents. At least two drivers have died in the U.S. while the system was engaged. Most recently, a driver in Mountain View, California, died after crashing into a concrete divider while his vehicle had Autopilot engaged. Before that, a man died in Florida while the system was engaged.

Autopilot is a Level 2 system on a 0-5 scale drawn up by the the Society of Automotive Engineers, where 0 indicates no autonomy and 5 indicates a fully autonomous vehicle. Autopilot can perform some functions, such as help keep a car in its lane. Musk has said that all Tesla cars now made are equipped with all of the hardware needed for full autonomy, a claim others working on self-driving cars have disputed.