California Clean Truck Check Adds J1979-2 Telematics Support

California fleets have a new telematics option for meeting Clean Truck Check emissions-testing requirements on newer heavy-duty vehicles. TheTrucker.com reported October 9 that Geotab received California Air Resources Board certification to add the SAE J1979-2 diagnostic protocol to its connected Clean Truck Check service. The integration is designed to collect and prepare required emissions data through compatible GO9-family devices without a separate manual scan.

J1979-2 is the newer onboard-diagnostics standard used by certain vehicles alongside the J1939 and earlier J1979 protocols. Geotab says its device can identify the eligible vehicle's protocol automatically, allowing a mixed fleet to use one workflow. That can reduce shop visits and administrative handling, but certification of a device does not transfer the fleet's underlying compliance responsibility to the vendor.

CARB guidance says vehicles using J1979-2 with compliance deadlines on or after January 1, 2027, must complete their onboard-diagnostic tests with equipment that supports the protocol. The agency also requires periodic tests to be submitted through a CARB-certified device. Clean Truck Check applies to covered heavy-duty vehicles operating in California, including trucks registered in another state, so interstate carriers should not assume an out-of-state plate creates an exemption.

Fleet managers should first confirm each truck's model year, diagnostic protocol and testing deadline in the CARB system. Then verify that the exact hardware and service configuration appears on the agency's certified-device list, assign continuously connected equipment to the correct vehicle and retain submission records. Drivers should know whether a truck is cleared before dispatch into California. A telematics connection can streamline the test, but registration, fees, accurate vehicle data and timely passing results remain essential parts of compliance.