CARB Clean Truck Check 2026: Compliance & Tracking Software

Clean Truck Check — also called the Heavy-Duty Inspection and Maintenance (HD I/M) program — is a California Air Resources Board regulation born from Senate Bill 210 (2019) that requires periodic emissions testing for heavy-duty vehicles operating on California roads. It became effective October 1, 2024 with the first compliance deadlines on January 1, 2025. Nearly all diesel, alternative fuel, and hybrid vehicles over 14,000 pounds GVWR are subject to the program, regardless of registration state — meaning out-of-state fleets operating in California carry the same obligations as California-registered operators. Agricultural vehicles and California-registered motorhomes for recreational or emergency use are subject to reduced (annual) testing frequency. Compliance requires reporting the vehicle to CTC-VIS, paying the annual $31.18 compliance fee, and submitting passing emissions tests by each compliance deadline. Non-compliance can result in DMV registration blocks and enforcement penalties. Always verify current scope and exemption criteria directly with CARB.

Clean Truck Check follows a phased schedule. For 2025 and 2026, most vehicles subject to the program must complete emissions testing twice per year — semi-annually — with deadlines tied to the DMV registration expiration date and 6 months after that date. Starting October 1, 2027, testing frequency increases to four times per year (quarterly) for vehicles equipped with On-Board Diagnostic (OBD) systems, which covers the majority of modern heavy-duty trucks. Older vehicles that undergo opacity testing rather than OBD-based testing remain on the semi-annual schedule. Agricultural vehicles and California-registered motorhomes are required to test annually only. Passing tests can be submitted up to 90 days before each compliance deadline — this window is intentional, giving fleets time to test, identify failures, complete repairs, and retest before the deadline hits. Testing on Day 5 of the window rather than Day 85 is the single most effective way to avoid missed deadlines.

CARB accepts four testing methods. First, testing at a certified testing facility — a smog or emissions shop with a CARB credentialed tester on staff, typically consuming 2–4 hours per truck including transit. Second, PEAQS (Portable Emissions Acquisition and Quality Screening) — mobile testing that can be brought to the fleet yard or roadside, usually about 30 minutes per truck. Third, a non-continuously-connected OBD scan tool operated by an internally credentialed tester — approximately 15 minutes per truck per test event, performed in the fleet yard. Fourth, a continuously-connected telematics device that is CARB-certified — the device captures OBD data during normal vehicle operation and submits it automatically, producing zero incremental downtime per test. All test submissions must be performed by a CARB credentialed tester (except the fully automated telematics option, where the certified device performs the reporting). The Tester Training Course is free through CARB, requires an 80% exam score, and the certificate renews every two years.

Missing a compliance deadline escalates through several enforcement layers. Immediately, the vehicle is out of compliance in the CTC-VIS system, which is visible to CARB enforcement and cross-referenced with the California DMV. The most direct consequence is a DMV registration block — the vehicle cannot renew its California registration until compliance is restored, and for out-of-state vehicles, the compliance status affects the ability to legally operate on California roads. Vehicles flagged as high emitters through roadside emissions monitoring devices or automated license plate readers may receive a Notice to Submit to Testing, which requires a passing test within 30 calendar days — barely enough time if repair work is needed. Beyond the operational impact, fines and enforcement penalties may apply, and repeated non-compliance can trigger additional compliance testing requirements. The financial hit from a single missed deadline typically outweighs a year's worth of compliance fees, because the affected vehicle sits idle while the compliance status is restored.

Effective tracking is per-asset, not fleet-wide. Every subject vehicle has its own two compliance deadlines per year (semi-annual, or quarterly starting October 2027 for OBD-equipped units) that are tied to its specific DMV registration expiration date, not a fleet-wide date. The tracking essentials per asset are: current DMV registration expiration; both computed CTC deadlines; last test date, method, and result; last CTC-VIS submission confirmation; aftertreatment fault history that could affect test readiness; and annual $31.18 compliance fee payment status. A fleet compliance software that opens each asset's 90-day pre-deadline window as a scheduled task — with 90-, 60-, and 30-day alerts — converts what would otherwise be a spreadsheet crisis into a routine maintenance flow. Fleets that adopt this discipline typically produce zero missed deadlines and catch aftertreatment issues that would have failed a test weeks before the test window opens. Always verify current CARB rules and requirements directly at ww2.arb.ca.gov as the program continues to evolve.