California Air Resources Board

CARB maintains two separate and ongoing in-use vehicles programs, the In-Use Compliance Program and the In-Use Vehicles Surveillance Program.  These in-use programs though similar in their procurement and testing of privately owned vehicles are utilized for very different purposes with the data generated.

In-Use Compliance Program

IUCP is a key strategy, beginning in 1983, to help California meet ambient air quality standards by ensuring that vehicles do not exceed their emissions standard over time, or their useful life period.  The In-Use Compliance Program relies on California vehicle owners willing to participate in a CARB emissions testing program.  A limited number of private vehicles, of a given test group or engine family, will be procured, inspected, and if needed, minor adjustments to restore the engine to the manufacturer's specifications are completed.  Lastly, the vehicle will undergo emissions testing identical to the testing done by the manufacturer during the vehicle’s emissions certification process.  The emissions testing, defined in Code of Federal Regulations, is done at the CARB Haagen-Smit Laboratory in El Monte, and observed by representatives from the vehicle manufacturer and the CARB test engineer. 

If tested vehicles exceed their specified emissions standard, by test group, the vehicle manufacturer is required to investigate the nonconformity and begin corrective action to correct the nonconformity and ensure that all affected vehicles, identified by test group, operate below their emissions standards.  The corrective action, usually in the form of a statewide recall in which the manufacturer will notify all affected vehicle owners about the issue, what to do to remedy the issue, where the get the necessary repairs, and that the manufacturer will provide the remedy and repair at no cost to the vehicle owner. 

In-Use Verification Program

IUVP is a vehicle testing requirement manufacturers perform annually that monitors emissions and allows CARB and EPA to identify potential concerns. A small sample of vehicles per test group are randomly selected, procured, and tested based on sales volume. The vehicles are grouped and tested by model and mileage. Vehicles with at least 10,000 miles and 1 year of service are tested in the Low Mileage group and vehicles with at least 50,000 miles and 4 years of service are tested in the High Mileage group. If necessary, IUVP can quickly launch into an In-Use Compliance Program if failure criteria are met defined in the Code of Federal Regulations.