Below is a notification from CARB that vehicle owners should be familiar with to ensure you pass your OBD test.
Clean Truck Check (CTC) first-phase readiness criteria will require a minimum of Operation Since codes Cleared (OSC). If the vehicle’s test result does not meet that minimum, the vehicle result will be NOT READY and will not pass the OBD test. This initial phase has a very low OSC threshold and will be increased over time to ensure the vehicle has had adequate operation for emissions monitors to complete their diagnostics checks.
Phase 1 Minimum OSC based on this:
3 Warm-Up Cycles (WUC).
If the vehicle OBD system does not collect WUC, the CTC test will check for a minimum of 100 miles of OSC.
If neither WUC nor mileage is in the test record, the CTC test will check for a minimum of 200 minutes of OSC.
Credentialed Testers: Please check with vehicle owners to ensure they have met the readiness criteria before performing the test. If there is any uncertainty on the vehicle owners' part, remind them to review the readiness criteria and consider additional vehicle operation before proceeding. Ensuring that the vehicle meets all readiness requirements will help avoid unnecessary test failures and the need for retesting.
Getting ready for the CTC OBD test
Things to do to have the best chance at passing the CTC OBD test:
If the Malfunction Indicator Light (right) is on, remind owners to get the vehicle repaired as soon as possible.
Don’t wait - Remind owners to have the OBD test early in the inspection compliance window so there will be time to complete the test if there are problems.
Remind owners to avoid clearing codes. OBD systems require substantial vehicle operation to be able to complete their emission control diagnostic tests. A vehicle that has not been operated enough, or has too many monitors incomplete, will fail the test.
Comments