Sacramento, California – The California Air Resources Board (ARB) has fined Nissan Motor Company US$4.4 million for failing to meet diagnostic equipment requirements on more than 450,000 vehicles.

The vehicles, from model years 2005 to 2007, did not comply with requirements that the equipment monitor tailpipe emissions and turn on a “check engine” light to alert the driver if tailpipe emissions stray from permissible levels.

The ARB discovered the problems in 2007, during a routine compliance review. The problems concerned inadequate monitoring of engine sensors that govern proper fuel system operation, and whether monitoring takes place as frequently as required.

“California advanced the goal of clean air by pioneering the development and use of the on-board diagnostic system to make sure drivers know when their emissions equipment malfunctions,” said ARB chair Mary Nichols. “We consider it to be a vital tool not only for consumers, but for all of us who want to breathe clean air. Nissan has been cooperative during this investigation, and we are confident that the design process changes they implemented will prevent future problems.”

Nissan’s settlement requires it to pay $3 million to the California Air Pollution Control Fund, $1.2 million to the Environmental Education Initiative, and $200,000 to the National OBD Clearinghouse.