If you have ever wondered what actually happens when a mobile CARB tester shows up to your yard, this walkthrough covers the entire process from first call to compliance confirmation.
The short version: you call or submit a request, we show up at your location, test your trucks on-site, and handle the CARB paperwork. Most fleet operators are done in under two hours with zero downtime beyond the test itself.
Step 1: Book your appointment
Getting started takes about two minutes. You can submit a request online or call (916) 890-4427 directly. We need three things:
- Your location — the address where the trucks are parked
- Number of vehicles — how many trucks, buses, or motorhomes need testing
- Engine years — this determines whether each vehicle needs OBD or OVI testing
We schedule appointments Monday through Saturday across our service area: Sacramento, Stockton, Fairfield, San Jose, and the entire Bay Area. Most appointments are available within the same week.
Step 2: We come to your yard
On the scheduled day, our certified tester arrives at your location with all necessary equipment. There is nothing you need to prepare beyond having the vehicles accessible — engines off, keys available.
For OBD testing (2013+ engines), the tester connects a diagnostic tool to each vehicle's OBD port, typically located under the dashboard. The tool reads emissions-related fault codes from the engine control module. The entire process takes about 10 to 15 minutes per vehicle.
For OVI testing (pre-2013 engines), the tester uses a calibrated opacity meter positioned at the exhaust outlet. The engine is run through a series of controlled snap-accelerations while the meter measures smoke density. This takes about 15 to 20 minutes per vehicle.
Step 3: Results on the spot
You get your pass or fail result immediately after each vehicle is tested. There is no waiting period — the diagnostic readout or opacity measurement gives a definitive answer on the spot.
If a vehicle passes, you are done with that truck. The compliance record is submitted to CARB electronically.
If a vehicle fails, the tester can typically identify the root cause during the test. Common issues include DPF (diesel particulate filter) problems, faulty O2 sensors, exhaust leaks, or engine control module faults. You get a clear explanation of what needs repair and can schedule a retest after the work is done.
Step 4: CARB paperwork handled
After testing, we submit your results to CARB through the CTC-VIS (Clean Truck Check Vehicle Information System) portal. You do not need to file anything separately or visit a CARB office. Your compliance status updates automatically in the system.
You receive a test report for your records, and your vehicles are marked compliant in the CARB database. If you are enrolled in our Full Care program, we also track your next testing deadline and send reminders before it comes due.
What about fleet testing?
Fleet testing follows the same process — we just test multiple vehicles in sequence at the same location. This is where mobile testing provides the biggest advantage over stationary centers.
At a testing center, each truck has to be driven there individually, wait in line, get tested, and driven back. For a fleet of six trucks, that can consume an entire workday across multiple drivers.
With mobile testing, we come to your yard once and test all six trucks in sequence. Total time on-site: typically under two hours. Your drivers stay on their regular routes or assignments — no one has to make a trip to a testing center.
What does it cost?
NorCal CARB Mobile charges per vehicle with no trip fees or hidden costs:
- OBD test: $75 per vehicle
- OVI (smoke) test: $199 per vehicle
- Motorhome OBD: $99 per vehicle
- Motorhome OVI: $229 per vehicle
Fleet and multi-truck discounts are available. Contact us for a quote.
Ready to schedule?
Most appointments are available within the same week, including Saturdays. Book a test or call (916) 890-4427.
Skip the testing center
We come to your yard and test your trucks on-site. Same-week appointments across Northern California.