Starting on July 19, 2021, smog testing procedures in California will check for modified or non-CARB compliant software in cars. Practically, that will mean that cars with ECU tunes not approved by the California Air Resources Board (CARB) will not pass their smog test.
According to the Bureau of Automotive Repair (BAR), if your car fails its smog check for this reason, you can have it returned to its OEM software version and re-tested. If you unknowingly bought a modified car, you can file a complaint with the bureau.
We’ve reached out to BAR for more information, but Tire Meets Road reports that California has been moving towards OBD-II diagnostics port-based tests for cars from 2000 or later for the last 10 years. Since 2015, smog check machines have been required to communicate with BAR’s database, giving the bureau a wide foundation of information to develop a profile for what a given vehicle’s stock ECU should look like, with room for any abnormalities that wouldn’t qualify as a tune or a smog-failing infringement.
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The good news is that flash-tuned cars can be changed back to their stock configuration fairly simply. There are also companies that provide CARB-certified tunes.
These can be checked for with something called a CVN. Also referred to as a Check Sum, it’s a set number that your car calculates by running several calculations using data programmed into your ECU. It essentially checks if all of your engine’s operations are running correctly.
This is useful for automakers because if the Check Sum doesn’t add up to the number set by the OEM, the car can take corrective action to prevent damage from occurring in your engine. CARB-certified tunes are registered with the BAR and the smog check will recognize them.
As the latest measure designed to ensure that CARB emissions requirements are being met, this will undoubtedly give a few enthusiasts a bit of a headache. But, hopefully, they can at least go into their smog check armed with the knowledge that will help them pass their test.
