OBD Testing
OBD Clean Truck Check at your yard. Same-day results.
Mobile OBD Clean Truck Check testing for 2013 and newer heavy-duty diesel engines. Credentialed tester on-site, results uploaded instantly, DMV hold typically clears same business day.
What OBD testing covers
The electronic test for modern diesel fleets
CARB's Clean Truck Check program requires all 2013 and newer heavy-duty diesel engines with a GVWR over 14,000 pounds to submit periodic OBD (On-Board Diagnostics) compliance tests. The test verifies three things: no active emissions-related trouble codes, completed readiness monitors, and clean communication with the engine's emissions control module.
When your truck passes, the result transmits electronically to CARB in near-real-time. CARB then releases the compliance record to DMV the same business day. If you had a registration hold, it typically lifts within hours.
Vehicles we test with OBD
- • Class 7 and Class 8 heavy-duty trucks (2013+)
- • School buses, motor coaches, and transit buses (2013+)
- • Heavy-duty motorhomes and RVs over 14,000 lbs GVWR
- • Refrigerated delivery trucks, dump trucks, and service fleets
- • Agricultural and utility heavy-duty trucks
How the test runs on-site
- 1. Arrival and check-in. Our credentialed tester confirms your vehicle(s), VINs, and your CARB Clean Truck Check account.
- 2. Scan tool connection. Certified OBD scanner connects to the truck's diagnostic port. The engine is run briefly to verify communication.
- 3. Data capture. The scanner records MIL status, DTCs, readiness monitors, and compliance data.
- 4. Upload to CARB. Results submit electronically while we are still on-site. You receive a digital confirmation.
- 5. Invoice and depart. Cards, e-check, or cash accepted. We can test the next vehicle or head to the next stop.
Quick facts
- Time per vehicle
- 15-20 minutes
- Engine years covered
- 2013 and newer
- DMV clearance
- Same business day on pass
- Results delivery
- Instant, electronic
- Service area
- Sacramento + 100 mi NorCal
Frequently asked questions
What is OBD testing under CARB Clean Truck Check?
OBD (On-Board Diagnostics) testing reads the vehicle's emissions control computer using a certified scan tool. It verifies the engine computer reports no active MIL (Check Engine) codes and that all emissions monitors are ready. CARB requires OBD testing for all 2013 and newer heavy-duty diesel engines.
How long does an OBD test take?
About 15 to 20 minutes per vehicle on average. Setup, scan, upload, and we move to the next truck. Larger fleets can be cycled through quickly because the electronic procedure is fast.
Why do OBD tests clear DMV holds faster than OVI?
OBD results transmit electronically to CARB in near-real-time. CARB releases the compliance record to DMV the same business day. By contrast, OVI tests require manual processing by CARB, which takes several business days.
What makes a truck fail an OBD test?
Three common reasons: an active MIL (Check Engine) code, incomplete readiness monitors (the computer has not run its self-tests since a recent battery disconnect or repair), or communication failure with the emissions control unit. We diagnose which category applies and give you a clear path to fix it.
Do I need to prepare the truck before your tester arrives?
Have the vehicle parked with engine accessible, a fully charged battery, and ideally the last 50 to 100 miles of normal driving completed so readiness monitors are set. Bring your CARB Clean Truck Check account login if you have it. That is all.
Clean Truck Check guides
A clear breakdown of CARB Clean Truck Check costs in 2026, including the $32.13 state compliance fee, test fees, and the hidden expense of drive-in testing.
How CARB Clean Truck Check deadlines work, what happens when you miss one, and the quarterly testing change coming in October 2027.
What to do after a failed CARB Clean Truck Check — diagnosing the cause, repairing, retesting, and restoring compliance to clear your DMV hold.
A complete guide to the CARB Clean Truck Check program — what it is, who it applies to, how testing works, and how to stay compliant in 2026.
Book your OBD Clean Truck Check
Book OBD testing for a single truck or a full fleet. Most Sacramento-area appointments available within 24 hours.