If you run trucks through Sacramento yards, West Sacramento industrial parks, or delivery stops off I-80 and Highway 50, the most expensive Clean Truck Check mistake is usually not the test itself. It is missing the real compliance month and finding out too late that the vehicle still shows incomplete in CTC-VIS.
Useful CARB fact: for compliance deadlines on or after January 1, 2025, you need a passing emissions compliance test on file, and CARB allows that passing test to be submitted no more than 90 days before the vehicle's deadline. That window matters because it gives fleets time to fix a problem before the due month hits.
At NorCal CARB Mobile, the practical goal is simple. We show up, complete the right test in the field, and leave you with an actual done item instead of a "we still need to book that truck" note. For newer engines, that usually means an OBD submission. For older diesel units, that means OVI plus SAE J1667 smoke opacity testing where required.
And yes, this is the same kind of practical Sacramento timing people respect at old food landmarks like Jim-Denny's: know when to show up, get it done cleanly, and do not waste the window.
What actually makes a vehicle compliant
Reported in CTC-VIS: the vehicle and owner information must be in the system.
Annual fee paid: CARB still expects the compliance fee by the vehicle's deadline month.
No unresolved enforcement block: outstanding violations can still stop compliance.
Passing test on file: required for deadlines on or after January 1, 2025.
If one of those pieces is missing, the truck is not fully done, even if the driver thought the visit was handled.
California-registered vehicles: use the DMV month
For California-registered vehicles subject to the semi-annual schedule, the deadline tracks the DMV registration expiration month and then repeats six months later. That is the part many owners miss.
Examples based on CARB Table I:
January registration month: compliance months are January and July.
May registration month: compliance months are May and November.
October registration month: compliance months are October and April.
Always confirm the exact due month in your CTC-VIS account, because that is what CARB uses for status.
Non-California and DMV-exempt vehicles: use the last VIN digit
If the vehicle is not California-registered, or it is DMV-exempt, the schedule comes from the last digit of the VIN under CARB Table II.
Examples from the official table:
VIN ending in 0: April and October.
VIN ending in 4: February and August.
VIN ending in 9: January and July.
Do not guess from your dispatch calendar. Use the VIN rule and verify in CTC-VIS.
What test does the truck actually need?
The engine model year decides the test path:
2013 and newer diesel engines: OBD testing with a CARB-certified device.
2012 and older diesel engines: OVI plus SAE J1667 smoke opacity testing.
2018 and newer alternative-fuel engines: OBD testing.
2017 and older alternative-fuel engines: OVI only.
That distinction matters when you are lining up multiple units at one yard and want the visit to end with real completions, not partials.
What a useful field completion looks like
A sales-useful proof point is not fancy language. It is a truck that had the right mobile visit, the right test, and the result submitted inside the allowed window. When a Sacramento fleet manager can point to a truck and say, "that one is done," they mean the OBD or OVI/J1667 step is complete and documented for the deadline in front of them.
Best next move for 2025
Pull your unit list, group it by California registration month or last VIN digit, and book the trucks that are already inside their 90-day window. That keeps the work practical and avoids deadline-week scrambling.
Need mobile Clean Truck Check help in Sacramento or across Northern California? Call 916-890-4427 and we can help you sort the right test path before the due month sneaks up on you.
Book a test or call (916) 890-4427 to schedule mobile Clean Truck Check testing.